High Energy Physics - Phenomenology
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- [1] arXiv:2406.12936 [pdf, html, other]
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Title: Global fits of proton PDFs with non-linear corrections from gluon recombinationComments: to appear in the proceedings of the 31st International Workshop on Deep Inelastic Scattering (DIS2024), 8-12 April 2024, Grenoble, FranceSubjects: High Energy Physics - Phenomenology (hep-ph)
We present numerical studies of the leading non-linear corrections to the DGLAP evolution equations of parton distribution functions (PDFs) resulting from gluon recombination, which reduce the pace of evolution at small momentum fractions $x$. The non-linear evolution is implemented in the \textsc{HOPPET} and \textsc{xFitter} toolkits and used to carry out fits of proton PDFs using lepton-proton deep inelastic scattering data from HERA, BCDMS and NMC. While we do not find evidence for non-linear effects, we are able to set upper limits for their strength. We also quantify the potential impact of longitudinal structure function measurements at the Electron-Ion Collider and the Large Hadron Electron Collider on future fits.
- [2] arXiv:2406.12956 [pdf, html, other]
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Title: Cold Darkogenesis: Dark Matter and Baryon Asymmetry in Light of the PTA SignalComments: 5 + 4 pages, 3 figuresSubjects: High Energy Physics - Phenomenology (hep-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Experiment (hep-ex); High Energy Physics - Theory (hep-th)
We build upon the intriguing possibility that the recently reported nano-Hz gravitational wave signal by Pulsar Timing Array (PTA) experiments is sourced by a strong first-order phase transition from a nearly conformal dark sector. The phase transition has to be strongly supercooled to explain the signal amplitude, while the critical temperature has to be in the $\cal{O}$(GeV) range, as dictated by the peak frequency of the gravitational wave spectrum. However, the resulting strong supercooling exponentially dilutes away any pre-existing baryon asymmetry and dark matter, calling for a new paradigm of their productions. We then develop a mechanism of cold darkogenesis that generates a dark asymmetry during the phase transition from the textured dark $SU(2)_{\rm D}$ Higgs field. This dark asymmetry is transferred to the visible sector via neutron portal interactions, resulting in the observed baryon asymmetry. Furthermore, the mechanism naturally leads to the correct abundance of asymmetric dark matter, with self-interaction of the scale that is of the right order to solve the diversity problem in galactic rotation curves. Collider searches for mono-jets and dark matter direct detection experiments can dictate the viability of the model.
- [3] arXiv:2406.12961 [pdf, html, other]
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Title: LO, NLO, and NNLO Parton Distributions for LHC Event GeneratorsComments: 14 pages, 9 figures, PDF sets available from this https URLSubjects: High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Experiment (hep-ex)
We present NNPDF4.0MC, a variant of the NNPDF4.0 set of parton distributions (PDFs) at LO, NLO and NNLO, with and without inclusion of the photon PDF, suitable for use with Monte Carlo (MC) event generators, which require PDFs to satisfy additional constraints in comparison to standard PDF sets. These requirements include PDF positivity down to a low scale $Q\sim 1$ GeV, smooth extrapolation in the very small and large $x$ regions, and numerically stable results even in extreme regions of phase space for all PDFs. We compare the NNPDF4.0MC PDFs to their baseline NNPDF4.0 counterparts, and to the NNPDF2.3LO set entering the Monash tune of the Pythia8 event generator. We briefly assess the phenomenological impact of these PDFs on the cross-sections for hard and soft QCD processes at the LHC.
- [4] arXiv:2406.12970 [pdf, html, other]
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Title: Warm and Fuzzy Dark Matter: Free Streaming of Wave Dark MatterComments: 16 pages, 11 figuresSubjects: High Energy Physics - Phenomenology (hep-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO)
Wave or fuzzy dark matter that is produced with relativistic wavenumbers exhibits free streaming effects analogous to warm or hot particle dark matter with relativistic momenta. Axions produced after inflation provide such a warm or mildly relativistic candidate, where the enhanced suppression and observational bounds are only moderately stronger than that from wave propagation of initially cold axions. More generally, the free streaming damping also impacts isocurvature fluctuations from generation in causally disconnected patches. As coherent spatial fluctuations free stream away they leave incoherent and transient superpositions in their wakes. These multiple wave momentum streams are the wave analogue of particle phase space fluctuations or directional collisionless damping of massive neutrinos or hot dark matter. The observable impact on both adiabatic and isocurvature fluctuations of fuzzy dark matter can differ from their cold dark matter counterparts due to free streaming depending on how warm or hot is their momentum distribution.
- [5] arXiv:2406.13001 [pdf, html, other]
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Title: Echoes of Veltman criteria on the next-two-Higgs-doublet modelComments: 27 pages, 7 figures, 9 tablesSubjects: High Energy Physics - Phenomenology (hep-ph)
We investigate how the Next-Two-Higgs Doublet Model extension (N2HDM) should look if we are to address the naturalness problem using dimensional regularization. In such a model, new Higgs states are predicted, namely: three CP-even $h_{1,2,3}$, one CP-odd $A$, and a pair of charged Higgs boson $H^\pm$. Our calculations of the overall quadratic divergences have been performed with full consistency with the latest data from the Large Hadron Collider (LHC) concerning the observed 125 GeV Higgs boson, alongside precision electroweak data tests and lower mass limits on charged Higgs boson. It is shown that the quadratically divergent quantum corrections $\delta_i$ (i=1,2,3) for the three CP-even Higgs bosons are controllably small, though hidden fine-tuning might still be required. This reveals a significant impact on the model parameter space, Higgs spectrum mass, and notably the singlet-doublet admixture.
- [6] arXiv:2406.13074 [pdf, html, other]
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Title: PIPPIN: Generating variable length full events from partonsSubjects: High Energy Physics - Phenomenology (hep-ph); Machine Learning (cs.LG); High Energy Physics - Experiment (hep-ex); Machine Learning (stat.ML)
This paper presents a novel approach for directly generating full events at detector-level from parton-level information, leveraging cutting-edge machine learning techniques. To address the challenge of multiplicity variations between parton and reconstructed object spaces, we employ transformers, score-based models and normalizing flows. Our method tackles the inherent complexities of the stochastic transition between these two spaces and achieves remarkably accurate results. The combination of innovative techniques and the achieved accuracy demonstrates the potential of our approach in advancing the field and opens avenues for further exploration. This research contributes to the ongoing efforts in high-energy physics and generative modelling, providing a promising direction for enhanced precision in fast detector simulation.
- [7] arXiv:2406.13135 [pdf, html, other]
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Title: Pair creation in electric fieldsComments: 10 pages, 6 figures, to appear in the Proceedings of "45th Symposium on Nuclear Physics", Cocoyoc, Mexico, Jan 8-11, 2024Subjects: High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Theory (hep-th)
Sauter-Schwinger pair creation in electromagnetic fields is a fundamental prediction of QED and one of the motivations for the present efforts in constructing super-strong lasers. I will give a historical review of the subject, and then focus on two recent developments. The first one is the worldline instanton formalism, a sophisticated version of the WKB approximation that makes it possible to calculate the pair creation rate for complicated field configurations. The second one is an adaptation of the Dirac-Heisenberg-Wigner formalism suitable for a detailed study of the formation of real particles in time and space.
- [8] arXiv:2406.13234 [pdf, html, other]
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Title: Probing ALP Lepton Flavour Violation at $\mu$TRISTANComments: 30 pages, 10 figures, 8 tablesSubjects: High Energy Physics - Phenomenology (hep-ph)
Axion-like particles (ALPs) with lepton flavour violating (LFV) interactions are predicted within a wide range of flavoured ALP models. The proposed $\mu$TRISTAN high-energy $e^-\mu^+$ and $\mu^+\mu^+$ collider will provide a good opportunity to explore flavour physics in the charged lepton sector. In this work, based on a model-independent effective Lagrangian describing the ALP leptonic interactions, we investigate the potential of $\mu$TRISTAN to probe ALP LFV couplings. We analyse the testability of selected ALP production channels with potential sensitivity at $\mu$TRISTAN, considering different beams and collision energies, including $e^- \mu^+ \to a \gamma$, $e^- \mu^+ \to e^- \tau^+ a$, $\mu^+ \mu^+ \to \mu^+ \tau^+ a$, and $e^- \mu^+ \to \tau^- \mu^+ a$. The produced ALP $a$ is either long-lived or can promptly decay to flavour violating or conserving charged lepton final states. In particular, combining the above LFV ALP production modes with a suitable LFV decay mode, one can identify signatures that are virtually free of Standard Model background. We show the resulting sensitivity of $\mu$TRISTAN to LFV ALP couplings and compare it with multiple low-energy leptonic constraints and the future improvements thereof. We find that $\mu$TRISTAN can be generally complementary to searches for low-energy LFV processes and measurements of the leptonic magnetic dipole moments and has the capability to explore unconstrained parameter space for ALP masses in the $\mathcal{O}(1)$ to $\mathcal{O}(100)$~GeV range. In the light ALP regime, however, the parameter space that $\mu$TRISTAN is sensitive to, has been already excluded by low-energy searches for LFV decays.
- [9] arXiv:2406.13286 [pdf, html, other]
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Title: Charm and Bottom Hadrons in Hot Hadronic MatterComments: 60 pages, 45 figures. Review article sent to Physics Reports journalSubjects: High Energy Physics - Phenomenology (hep-ph); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
Heavy quarks, and the hadrons containing them, are excellent probes of the QCD medium formed in high-energy heavy-ion collisions, as they provide direct information on the transport properties of the medium and how quarks color-neutralize into hadrons. Large theoretical and phenomenological efforts have been dedicated thus far to assess the diffusion of charm and bottom quarks in the quark-gluon plasma and their subsequent hadronization into heavy-flavor (HF) hadrons. However, the fireball formed in heavy-ion collisions also features an extended hadronic phase, and therefore any quantitative analysis of experimental observables needs to account for rescattering of charm and bottom hadrons. This is further reinforced by the presence of a QCD cross-over transition and the notion that the interaction strength is maximal in the vicinity of the pseudo-critical temperature. We review existing approaches for evaluating the interactions of open HF hadrons in a hadronic heat bath and the pertinent results for scattering amplitudes, spectral functions and transport coefficients. While most of the work to date has focused on $D$ mesons, we also discuss excited states as well as HF baryons and the bottom sector. Both the HF hadro-chemistry and bottom observables will play a key role in future experimental measurements. We also conduct a survey of transport calculations in heavy-ion collisions that have included effects of hadronic HF diffusion and assess their sensitivity to various observables.
- [10] arXiv:2406.13304 [pdf, html, other]
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Title: Dimuon production in neutrino-nucleus collisions -- the SIDIS approachComments: To appear in the proceedings of the 31st International Workshop on Deep Inelastic Scattering (DIS2024), 8-12 April 2024, Grenoble, FranceSubjects: High Energy Physics - Phenomenology (hep-ph)
Dimuon production is in many global parton distribution function analyses calculated by assuming that it is proportional to inclusive charm production. As this assumption breaks down at next-to-leading order in the perturbative expansion, we present a direct calculation of dimuon production that does not require an external acceptance correction. Our calculation utilizes semi-inclusive deep inelastic scattering and a decay function fitted to experimental data. We find our calculation to be in good agreement with available experimental data. Here we also demonstrate that the acceptance correction depends on the used parton distribution and perturbative order.
- [11] arXiv:2406.13306 [pdf, html, other]
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Title: Charge distributions of pseudo-scalar and vector mesons from Dyson-Schwinger equationsComments: 14 pages, 9 figuresSubjects: High Energy Physics - Phenomenology (hep-ph)
We combine the Dyson-Schwinger/Bethe-Salpeter equations framework with modern numerical reconstruction methods to derive the three-dimensional and transverse two-dimensional charge distribution of an array of ground-state pseudoscalar and vector mesons from their elastic electromagnetic form factor in the low-momentum region. The charge radii obtained by averaging over the reconstructed charge distributions have been checked to be consistent with those calculated from the slope of the elastic electromagnetic form factor at zero transferred momentum. The capability of the reconstruction procedure for capturing a reliable low-distance charge distribution is discussed and argued to work down to distances of around 0.1 fm, such that it might be potentially applied to extract, {\it e.g.}, mass densities from gravitational form factors.
- [12] arXiv:2406.13468 [pdf, html, other]
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Title: Leptogenesis assisted by scalar decaysComments: 18 pages, 8 figuresSubjects: High Energy Physics - Phenomenology (hep-ph)
We present a pragmatic approach to lower down the mass scale of right-handed neutrinos in leptogenesis by introducing a scalar decaying to right-handed neutrinos. The key point of our proposal is that the out-of-equilibrium decays of the scalar provide an additional source for right-handed neutrinos and hence the lepton asymmetry. This mechanism works well at low temperatures when the washout of the generated lepton asymmetry is suppressed. Thus, the lepton asymmetry can be effectively produced despite the washout effect is strong or not. Through a comprehensive analysis, we demonstrate that such a scalar-assisted leptogenesis can typically decrease the viable right-handed neutrino mass scale by two to four orders of magnitude.
- [13] arXiv:2406.13530 [pdf, html, other]
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Title: Resonances in the quark modelComments: 17 pages, To appear in Few-Body Systems, special issue on Critical StabilitySubjects: High Energy Physics - Phenomenology (hep-ph); Nuclear Theory (nucl-th)
A discussion is presented of the estimates of the energy and width of resonances in constituent models, with focus on the tetraquark states containing heavy quarks.
- [14] arXiv:2406.13531 [pdf, html, other]
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Title: LQCD constrained magnetic field dependent coupling constant in an effective modelComments: 8 pages, 4 figuresSubjects: High Energy Physics - Phenomenology (hep-ph); Nuclear Theory (nucl-th)
A magnetic field dependent coupling constant $G(eB)$ is investigated in the two-flavor magnetized NJL model. Based on LQCD results of the neutral (charged) pion mass spectra at vanishing temperature and finite magnetic field, we determine the $G(eB)=G^0(eB)$ ($G(eB)=G^+(eB)$) in the NJL model. $G^0(eB)$ and $G^+(eB)$ are both non-monotonic functions of magnetic fields, but they are different from each other. Furthermore, we calculate the pseudo-critical temperatures $T_{pc}(eB)$ of chiral restoration phase transition with $G^0(eB)$ and $G^+(eB)$ in the magnetized NJL model, respectively. The resulting $T_{pc}(eB)$ are non-monotonic functions of magnetic fields. In previous work, $G(eB)$ in the NJL model fitted from the chiral condensate or pseudo-critical temperature of LQCD simulations is a decreasing function of magnetic field. It can not explain the saturation behavior of mass spectra of neutral pion and decreasing behavior of mass spectra of charged pion with strong magnetic field. We conclude that a magnetic field dependent coupling constant $G(eB)$ in the NJL model can not simultaneously explain the reduction of pseudo-critical temperature of chiral restoration phase transition and the light meson mass spectra under external magnetic field.
- [15] arXiv:2406.13593 [pdf, html, other]
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Title: Neutrino trident scattering at the LHC energy regimeComments: 7 pages, 5 figuresSubjects: High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Experiment (hep-ex)
The neutrino trident scattering process in neutrino - tungsten interactions at the LHC energy regime is investigated, and the cross-sections for different leptonic final states in coherent and incoherent interactions are estimated. Furthermore, the associated number of eventsat FASER$\nu$2 detector is estimated considering different predictions for the flux of incident neutrinos on the detector, based on distinct hadronic models for the particle production in $pp$ collisions at ultra-forward rapidities. Our results indicate that the observation of the neutrino trident process is, in principle, feasible at the Forward Physics Facility.
- [16] arXiv:2406.13703 [pdf, html, other]
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Title: Working group 1 summary: $V_{ud}$, $V_{us}$, $V_{cd}$, $V_{cs}$ and semileptonic/leptonic $D$ decaysComments: 12 pages, 3 figures; presented at the 12th Workshop on the CKM Unitarity Triangle, 18-22 September 2023, Santiago de CompostelaSubjects: High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Experiment (hep-ex); High Energy Physics - Lattice (hep-lat); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
We summarize the program of working group 1 at the 12th Workshop on the CKM Unitarity Triangle, whose main subjects covered $V_{ud}$, $V_{us}$, and first-row unitarity as well as $V_{cd}$, $V_{cs}$, and (semi-)leptonic $D$ decays.
- [17] arXiv:2406.13727 [pdf, html, other]
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Title: Neutrino Tomography of the Earth: the Earth Total Mass, Moment of Inertia and Hydrostatic Equilibrium ConstraintsComments: 19 pages, LATEX. arXiv admin note: text overlap with arXiv:2111.13048Subjects: High Energy Physics - Phenomenology (hep-ph)
We investigate the implications of the constraints following from the precise knowledge of the total Earth mass, $M_\oplus$, and moment of inertia, $I_\oplus$, and from the requirement that Earth be in hydrostatic equilibrium (EHE), in the neutrino tomography studies of the Earth density structure. In order to estimate the sensitivity of a given neutrino detector to possible deviations of the inner core (IC), outer core (OC), core (IC + OC) and mantle Earth densities from those obtained using geophysical and seismological data and described by the preliminary reference Earth model (PREM), in the statistical analyses performed within the neutrino tomography studies one typically varies the density of each of these structures. These variations, however, must respect the $M_\oplus$, $I_\oplus$ and EHE constraints. Working with PREM average densities we derive the $M_\oplus$, $I_\oplus$ and EHE constraints on the possible density variations when one approximates the Earth density structure with i) three layers - mantle, outer core and inner core, and ii) four layers - upper mantle, lower mantle, outer core and inner core. We get drastically different results in the two cases.
- [18] arXiv:2406.13753 [pdf, html, other]
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Title: Non-global logarithms up to four loops at finite-N$_c$ for V/H+jet processes at hadron collidersComments: 26 pages, 11 figures, 1 tableSubjects: High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Theory (hep-th)
We extend our previous work [1] on calculating non-global logarithms in $e^+ e^-$ annihilation to Higgs/vector boson production in association with a single hard jet at hadron colliders. We analytically compute non-global coefficients in the jet mass distribution up to four loops using the anti-k$_t$ jet algorithm. Our calculations are performed in the eikonal approximation, assuming strong energy ordering for the emitted gluons, thus capturing only the leading logarithms of the distribution. We compare our analytical results with the all-orders large-N$_c$ numerical solution. In general, the gross features of the non-global logarithm distribution observed in the $e^+ e^-$ case remain valid for the V/H+jet processes.
- [19] arXiv:2406.13756 [pdf, html, other]
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Title: Multi-messenger Approach to Ultra-light ScalarsComments: 16 pages, 5 figures, 1 tableSubjects: High Energy Physics - Phenomenology (hep-ph); High Energy Astrophysical Phenomena (astro-ph.HE); General Relativity and Quantum Cosmology (gr-qc)
We propose a novel method to study the ultra-light scalars, where compact rotating objects undergo the phenomenon of superradiance to create gravitational waves and neutrino flux signals. The neutrino flux results from the 'right' coupling between the ultra-light scalars and the neutrinos. We study the intertwining of gravitational waves and neutrino flux signals produced from a single source and elaborate if and when the signals can be detected in existing and upcoming experiments in a direct manner. We also discuss an indirect way to test it by means of cosmic neutrino background which can be detected by upcoming PTOLEMY experiment.
- [20] arXiv:2406.13818 [pdf, html, other]
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Title: Effective theory tower for $\mu\rightarrow e$ conversionComments: 60 pages, 7 figures, 7 tables, to be submitted to JHEPSubjects: High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Experiment (hep-ex); Nuclear Theory (nucl-th)
We present theoretical predictions for $\mu \rightarrow e$ conversion rates using a tower of effective field theories connecting the UV to nuclear physics scales. The interactions in nuclei are described using a recently developed nonrelativistic effective theory (NRET) that organizes contributions according to bound nucleon and muon velocities, $\vec{v}_N$ and $\vec{v}_\mu$, with $|\vec{v}_N| > |\vec{v}_\mu|$. To facilitate the top-down matching, we enlarge the set of Lorentz covariant nucleon-level interactions mapped onto the NRET operators to include those mediated by tensor interactions, in addition to the scalar and vector interactions already considered previously, and then match NRET nonperturbatively onto the Weak Effective Theory (WET). At the scale $\mu \approx 2$ GeV WET is formulated in terms of $u$, $d$, $s$ quarks, gluons and photons as the light degrees of freedom, along with the flavor-violating leptonic current. We retain contributions from WET operators up to dimension 7, which requires the full set of 26 NRET operators. The results are encoded in the open-source Python- and Mathematica-based software suite MuonBridge, which we make available to the theoretical and experimental communities interested in $\mu \rightarrow e$ conversion.
- [21] arXiv:2406.13850 [pdf, html, other]
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Title: Quasi-Dirac Heavy Neutral Leptons in the Left-Right Symmetric ModelComments: 31 pages, 11 figuresSubjects: High Energy Physics - Phenomenology (hep-ph)
We discuss the phenomenology of a pair of degenerate GeV-scale Heavy Neutral Leptons within the Left-Right Symmetric Model (LRSM) framework, with the third fermion serving as a dark matter candidate. We highlight the potential of the recently approved SHiP experiment to test the existence of the light DM species, and the signatures of lepton number violation as a possible experimental probe of the model in various experiments. Our findings include concrete predictions, in some part of the model's parameter space, for the effective right-handed couplings $(V^{R}_{e})^2:(V^{R}_{\mu})^2:(V^{R}_{\tau})^2 = 0.16:0.47:0.38$ (normal neutrino hierarchy), $0.489 : 0.22 : 0.30$ (inverted hierarchy) of the degenerate pair.
- [22] arXiv:2406.14061 [pdf, html, other]
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Title: Topological diagrams of charmed baryon decays in the $SU(3)_F$ limitComments: 18 pages, 1 figureSubjects: High Energy Physics - Phenomenology (hep-ph)
Charm baryon decay palys an important role in studying the non-perturbative baryonic transition. In this work, we investigate the topological diagram of charmed baryon decays into light baryon octet and light meson by their invariant tensor expressions. The number of topologies contributing to the $\mathcal{B}_{c\overline 3}\to \mathcal{B}_8 M$ decay is counted by permutation. And the linear correlation of topologies in the $SU(3)_F$ limit is clarified by tensor analysis. It is found there are thirteen independent amplitudes contributing to the $\mathcal{B}_{c\overline 3}\to \mathcal{B}_8 M$ decays in the Standard Model.
- [23] arXiv:2406.14172 [pdf, html, other]
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Title: Dynamics of Phase Transition in Quark-Gluon Plasma Droplet Formation under Magnetic FieldSubjects: High Energy Physics - Phenomenology (hep-ph); Nuclear Theory (nucl-th)
Pre-existing density of states for a Quark-Gluon Phase, based on Thomas-Fermi and Bethe mode, is expanded by incorporation of new variables. Results from recent study indicate that perturbations in the form of a finite non-zero chemical potential T, B, dynamic thermal masses M and of course Temperature T are indeed vital to fully comprehend the formation and dynamics of QGP. Simulations depict an overall increase in the stability of QGP in the paradigm of the statistical model. On the top of Free Energy, Entropy and heat capacity are calculated for the phase transition. The overall qualitative behavior, of entropy or Heat Capacity determines the order of phase transition of the QGP. Investigation of order of phase transition is carried out in this study through Monte-Carlo based differential element, which ensures the inclusion of the randomness of the collisions at the particle colliders.
- [24] arXiv:2406.14202 [pdf, html, other]
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Title: {\pi} Meson-Octet Baryon Coupling Constant Obtained by Hard-Wall AdS/QCD ModelComments: 1 tableJournal-ref: Russian Physics Journal 67, no. 5 (2024): 660-666. Russian Physics Journal, Volume 67, Issue 5, p.660-666Subjects: High Energy Physics - Phenomenology (hep-ph)
The paper studies a strong coupling constant between {\pi} meson and octet baryon using the hard-wall AdS/QCD model, which considers SU(3)f symmetry-breaking effects. Briefly mentioned are profile functions for pseudoscalar meson and baryon fields. The obtained baryon coupling constants are in agreement with those obtained in theoretical calculations.
- [25] arXiv:2406.14389 [pdf, html, other]
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Title: Exploring new physics via effective interactionsComments: 14 pages, 8 figuresJournal-ref: International Journal of Modern Physics A (2024) 2450038Subjects: High Energy Physics - Phenomenology (hep-ph)
We investigate self-conjugate Dark Matter (DM) particles that primarily interact with standard model electroweak gauge bosons within an effective field theoretical framework. Our analysis focuses on effective contact interactions, invariant under the standard model gauge group, between Majorana fermions, and real scalar DM, with SM neutral electroweak gauge bosons. We calculate the Wilson coefficients for interaction terms up to dimension-8 and establish constraints on the theory's parameters. These constraints are derived from the observed relic density, and indirect detection observations. We discuss the potential for dark matter-nucleon scattering in direct detection experiments. Additionally, we utilize low-energy LEP data to assess sensitivity to the pair production of low-mass ($\leq$ 80 GeV) DM particles. Furthermore, we highlight the potential of the proposed International Linear Collider (ILC) in probing effective operators through the pair production of DM particles with masses $\geq$ 50 GeV in association with mono-photons.
- [26] arXiv:2406.14437 [pdf, html, other]
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Title: Complex Dark Photon Dark Matter EFTComments: 39 pages, 8 tables, 8 figuresSubjects: High Energy Physics - Phenomenology (hep-ph)
We construct an effective field theory for complex Stueckelberg dark photon dark matter. Such an effective construction can be realized by writing down a complete set of operators up to dimension six built with the complex dark photon and Standard Model fields. Classifying the effective operators, we find that in order to properly take into account the non-renormalizable nature of an interacting massive vector, the size of the Wilson coefficients should be naturally smaller than naively expected. This can be consistently taken into account by a proper power counting, that we suggest. First we apply this to collider bounds on light dark matter, then to direct detection searches by extending the list of non-relativistic operators to include the case of complex vectors. In the former we correctly find scaling limits for small masses, while in the latter we mostly focus on electric dipole interactions, that are the smoking gun of this type of dark matter. Simple UV completions that effectively realize the above scenarios are also outlined.
- [27] arXiv:2406.14454 [pdf, html, other]
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Title: Collective description of low energy mesonic statesSubjects: High Energy Physics - Phenomenology (hep-ph)
The phenomenology of hadronic states at high energy is well described in the framework of Quantum Chromodynamics. The theory, well established by now, cannot be applied to the description of quark-antiquark states at low energy unless their degrees of freedom are treated as effective ones, a condition resulting from confinement. Own to the similarities with other quantum many-body systems we have adopted a non-perturbative scheme where quarks are treated as quasiparticles, which further interact between them, allowing meson-like states to be described as collective superposition of quasiparticle-pairs. The results of the calculations, performed in the context of the random phase approximation method, show that this scheme is a suitable one to describe meson states up to energies of the order of couple of GeV.
- [28] arXiv:2406.14480 [pdf, html, other]
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Title: $P$ & $m_e$Subjects: High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Experiment (hep-ex)
Curiously in the minimal left right symmetric model, chiral ($\chi$) symmetry that protects the electron's mass ($m_e$), due to parity (P) implies the vanishing of its neutrino mixing angles. We break the $\chi$ symmetry to generate the observed neutrino mixing which causes the electron to acquire its mass on RGE running, and in turn determines the B-L gauge symmetry breaking scale ($v_R$) to be $10^{10} GeV \lesssim v_R \leq 10^{15} GeV $ (and with fine-tuning can be at $10 TeV$ scale). If the muon's mass is also generated radiatively, the B-L breaking scale is $\sim 10^{14-15}$ GeV. Regardless of how the high scale $v_R$ is, this is a testable model for obtaining the mass of the electron (and muon), since on RGE running and P breaking, a large strong CP phase ($\bar{\theta} >> 10^{-10}$) which depends logarithmically on $v_R$ is generated if there is O(1) CP violation in leptonic Yukawa couplings. Hence we expect that leptonic CP phases including the Dirac CP phase $\delta_{CP}$ of the PMNS matrix must be consistent with $0$ or $180^o$ to within a degree, which can be verified or excluded by neutrino experiments such as DUNE and Hyper-Kamiokande. In lieu of P, if charge conjugation C is used, the same results follow. However with C and no P, axions would likely need to be added anyway, in which case there is no constraint on $\delta_{CP}$.
New submissions for Friday, 21 June 2024 (showing 28 of 28 entries )
- [29] arXiv:2406.12713 (cross-list from hep-th) [pdf, other]
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Title: Structure of Massive Gauge/Gravity Scattering Amplitudes, Equivalence Theorems, and Extended Double-Copy with Compactified Warped SpaceComments: 84 pagesSubjects: High Energy Physics - Theory (hep-th); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Phenomenology (hep-ph)
We study the structure of scattering amplitudes of massive Kaluza-Klein (KK) states in the compactified 5-dimensional warped gauge and gravity theories. We present systematic formulations of the gauge theory equivalence theorem (GAET) and the gravitational equivalence theorem (GRET) for warped KK theories in $R_\xi^{}$ gauge, where the GAET connects the scattering amplitudes of longitudinal KK gauge bosons to that of the corresponding KK Goldstone bosons and the GRET connects the scattering amplitudes of KK gravitons of helicity-zero (helicity-one) to that of the corresponding gravitational KK Goldstone bosons. We analyze the structure of 3-point and 4-point scattering amplitudes of massive KK gauge bosons and of massive KK gravitons as well as their corresponding Goldstone bosons. We first prove the GAET and GRET explicitly for the fundamental 3-point KK gauge/gravity scattering amplitudes. We then demonstrate that the validity of the GAET and GRET for 4-point gauge/gravity scattering amplitudes can be reduced to the validity of GAET and GRET for 3-point gauge/gravity scattering amplitudes at tree level. With these, we study the double-copy construction of KK scattering amplitudes in the warped gauge/gravity theories. We newly realize the double-copy for massive 3-point full gauge/gravity amplitudes at tree level under proper correspondences of color-kinematics and of gauge/gravity couplings, whereas we can construct the double-copy for 4-point KK gauge/gravity amplitudes to the leading order (LO) of high energy expansion. We also conjecture that this LO double-copy construction can be extended to $N$-point scattering amplitudes with $N\!\geqslant\!5$.
- [30] arXiv:2406.12976 (cross-list from astro-ph.CO) [pdf, html, other]
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Title: Large Blue Spectral Index From a Conformal Limit of a Rotating Complex ScalarComments: 52 pages of main text, 13 figuresSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Phenomenology (hep-ph)
One well known method of generating a large blue spectral index for axionic isocurvature perturbations is through a flat direction not having a quartic potential term for the radial partner of the axion field. In this work, we show how one can obtain a large blue spectral index even with a quartic potential term associated with the Peccei-Quinn symmetry breaking radial partner. We use the fact that a large radial direction with a quartic term can naturally induce a conformal limit which generates an isocurvature spectral index of 3. We point out that this conformal representation is intrinsically different from both the ordinary equilibrium axion scenario or massless fields in Minkowski spacetime. Another way to view this limit is as a scenario where the angular momentum of the initial conditions slows down the radial field or as a superfluid limit. Quantization of the non-static system in which derivative of the radial field and the derivative of the angular field do not commute is treated with great care to compute the vacuum state. The parametric region consistent with axion dark matter and isocurvature cosmology is discussed.
- [31] arXiv:2406.12985 (cross-list from astro-ph.CO) [pdf, html, other]
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Title: CMB Spectral Distortions: A Multimessenger Probe of the Primordial UniverseComments: 8 pages, contribution to the 2024 Cosmology session of the 58th Rencontres de MoriondSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Phenomenology (hep-ph)
The frequency spectrum of the cosmic microwave background (CMB) is a relatively untapped source of data which can allow us to peer beyond the surface of last scattering. Small deviations away from a perfect blackbody shape will encode valuable information about the state of the primordial Universe which may not be accessible by other means. Here, we briefly review some key science goals of CMB spectral distortions, with an emphasis on how future generations of experiments can be used in tandem with complementary observational probes to perform model discrimination of exotic physics scenarios. We focus here on synergies between spectral distortions, gravitational waves, and 21cm cosmology.
- [32] arXiv:2406.13020 (cross-list from gr-qc) [pdf, html, other]
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Title: Microscale torsion resonators for short-range gravity experimentsSubjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Phenomenology (hep-ph); Instrumentation and Detectors (physics.ins-det)
Measuring gravitational interactions on sub-100-$\mu$m length scales offers a window into physics beyond the Standard Model. However, short-range gravity experiments are limited by the ability to position sufficiently massive objects to within small separation distances. Here we propose mass-loaded silicon nitride ribbons as a platform for testing the gravitational inverse square law at separations currently inaccessible with traditional torsion balances. These microscale torsion resonators benefit from low thermal noise due to strain-induced dissipation dilution while maintaining compact size (<100$\,\mu$g) to allow close approach. Considering an experiment combining a 40$\,\mu$g torsion resonator with a source mass of comparable size (130$\,\mu$g) at separations down to 25$\,\mu$m, and including limits from thermomechanical noise and systematic uncertainty, we predict these devices can set novel constraints on Yukawa interactions within the 1-100$\,\mu$m range.
- [33] arXiv:2406.13056 (cross-list from astro-ph.CO) [pdf, html, other]
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Title: Mildly boosted dark matter annihilation and reconciling indirect galactic signalsComments: 6 pages, 3 figuresSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics - Phenomenology (hep-ph)
The galactic center excess is a possible non-gravitational observation of dark matter; however, the canonical dark matter model (thermal freeze-out) is in conflict with other gamma-ray observations, in particular those made of the Milky Way's satellite dwarf galaxies. Here we consider the effects of a two-component dark matter model which results in minimally boosted particles that must remain bound to their host galaxy in order to produce an observational signal. This leads to a signal that is heavily dependent on galactic scale and can help reconcile the differences in the galactic center and dwarf galaxy measurements under the dark matter paradigm.
- [34] arXiv:2406.13082 (cross-list from gr-qc) [pdf, other]
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Title: The Hanbury-Brown and Twiss effect in inflationary cosmological perturbationsSubjects: General Relativity and Quantum Cosmology (gr-qc); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Theory (hep-th)
The simplest model of inflation is based around an inflaton field that starts in a coherent false vacuum state with a positive cosmological constant, rolls slowly to the true vacuum and relaxes to it via reheating. We examine whether the scale of the transition from coherence to chaoticity can be examined via the Hanbury-Brown and Twiss (HBT) effect, in parallel with analogous problems of heavy ion physics (the ``pion laser'' and the thermalizing glasma).
We develop an ansatz which contains a definition of ''chaoticity'' which parallels that of the usual setups where HBT is used.
However, we also discuss the differences between the inflationary setup and more mainstream uses of HBT and conclude that these are more significant than the similarities, making the use of the developed methodology uncertain. - [35] arXiv:2406.13394 (cross-list from gr-qc) [pdf, html, other]
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Title: Gravitational Wave Birefringence from Fuzzy Dark MatterComments: 7 pagesSubjects: General Relativity and Quantum Cosmology (gr-qc); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Phenomenology (hep-ph)
Gravitational wave (GW) birefringence is a remarkable phenomenon that can be used to test the parity violation in gravity. By coupling the fuzzy dark matter (FDM) scalar to the gravitational Chern-Simons term, we explore the GW birefringence effects in the FDM background. In particular, in light of the highly oscillating granular FDM structure at the galactic scale, we are led to investigating the GW propagation in the Chern-Simons gravity over the general nontrivial scalar profile, which is a natural extension of previous studies on the homogeneous and isotropic configurations. As a result, it is found that GWs of both circularly polarized modes propagate in the straight line with the speed of light, and does not show any velocity birefringence. However, when considering the imaginary part of the dispersion relation, GWs exhibit the amplitude birefringence in which one circular polarization is enhanced while the other suppressed. Due to its local nature, the FDM-induced amplitude birefringence only depends on the GW frequency without any reliance on the GW event distance. More importantly, the birefringence factor shows a periodic time variation with the period reflecting the FDM scalar mass, which is the smoking gun for testing this new birefringence mechanism. Finally, we also study the extra-galactic FDM contribution to the GW birefringence, which is shown to be suppressed by the cosmological DM density and thus subdominant compared with the galactic counterpart.
- [36] arXiv:2406.13480 (cross-list from astro-ph.CO) [pdf, html, other]
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Title: Neutron stars and Pulsar timing arrays as Axion giant gyroscopesComments: 6 pages, 2 figuresSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Phenomenology (hep-ph)
We consider the three-dimensional rotating motions of neutron stars blown by the "axion wind". Neutron star precession and spin can change from the magnetic moment coupling to the oscillating axion background field, in analogy to the gyroscope motions with a driving force and the laboratory Nuclear Magnetic Resonance(NMR) detections of the axion. This effect modulates the pulse arrival time of the pulsar timing arrays. It shows up as a signal on the timing residual and two-point correlation function on the recent data of Nanograv and PPTA. The current measurement of PTAs can thus cast constraints on the axion-nucleon coupling as g_{ann} ~ 10^{-12}{GeV}^{-1}.
- [37] arXiv:2406.13520 (cross-list from nucl-th) [pdf, html, other]
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Title: Energy dependence of particle production in Au+Au collisions at $\sqrt{s_{\text{NN}}}$ = 7.7-200 GeV using a multiphase transport modelSubjects: Nuclear Theory (nucl-th); High Energy Physics - Experiment (hep-ex); High Energy Physics - Phenomenology (hep-ph)
In this study, we employ a multi-phase transport (AMPT) model to understand the production of $\pi^{\pm}$, $K^{\pm}$, $p$, $\overline{p}$, $K^{0}_{s}$, $\Lambda$, $\bar{\Lambda}$, and $\phi$ in Au + Au collisions at $\sqrt{s_{NN}} = 7.7$, $27$, $39$, $62.4$, and $200$ GeV. We have studied the energy dependence of various bulk properties of the system such as transverse momentum ($p_T$) spectra, particle yields ($dN/dy$), mean transverse mass ($\langle m_T \rangle$), and anti-particle to particle ratios. Model calculations using both default and string melting versions of the AMPT with three distinct sets of initial conditions are compared to the data from the STAR experiment. In the case of $\pi^{\pm}$, $K^{\pm}$, $p$, and $\overline{p}$, we observe that the string melting version shows better agreement with data at higher energies, while the default version performs better at lower collision energies. However, for $K^{0}_{s}$, $\Lambda$, and $\phi$, it is observed that the default version is able to describe the data better at all energies. In addition, we have used the blast-wave model to extract the kinetic freeze-out properties, like the kinetic freeze-out temperature and the radial flow velocity. We observe that these parameters are comparable with the data.
- [38] arXiv:2406.13594 (cross-list from hep-th) [pdf, html, other]
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Title: Supergeometric Quantum Effective ActionComments: 45 pages, no figuresSubjects: High Energy Physics - Theory (hep-th); High Energy Physics - Phenomenology (hep-ph)
Supergeometric Quantum Field Theories (SG-QFTs) are theories that go beyond the standard supersymmetric framework, since they allow for general scalar-fermion field transformations on the configuration space of a supermanifold, without requiring an equality between bosonic and fermionic degrees of freedom. After revisiting previous considerations, we extend them by calculating the one-loop effective action of minimal SG-QFTs that feature non-zero fermionic curvature in two and four spacetime dimensions. By employing an intuitive approach to the Schwinger-DeWitt heat-kernel technique and a novel field-space generalised Clifford algebra, we derive the ultra-violet structure of all effective-field-theory (EFT) operators up to four spacetime derivatives that emerge at the one-loop order. Upon minimising the impact of potential ambiguities due to the so-called multiplicative anomalies, we find that the EFT interactions resulting from the one-loop supergeometric effective action are manifestly diffeomorphically invariant in configuration space. The extension of our approach to evaluating higher-loops of the supergeometric quantum effective action is described. The emerging landscape of theoretical and phenomenological directions for further research of SG-QFTs is discussed.
- [39] arXiv:2406.13643 (cross-list from hep-th) [pdf, html, other]
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Title: Geometry of Classical Nambu-Goldstone FieldsComments: 20 pagesSubjects: High Energy Physics - Theory (hep-th); Strongly Correlated Electrons (cond-mat.str-el); High Energy Physics - Phenomenology (hep-ph)
A coordinate-free formulation of first order effective field theory, in which Nambu-Goldstone fields are described as sections on associated bundle, is presented. This construction, which is based only on symmetry considerations, allows for a direct derivation of number and types of Nambu-Goldstone fields in a classical field theory without any reference to effective Lagrangian. A central role in classification is shown to be played by Lorentz-symmetry breaking order parameter which induces symplectic structure in the field space of the theory.
- [40] arXiv:2406.13717 (cross-list from nucl-th) [pdf, html, other]
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Title: Beyond modified Urca: the nucleon width approximation for flavor-changing processes in dense matterComments: 6 pages, 6 figuresSubjects: Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Phenomenology (hep-ph)
Flavor-changing charged current ("Urca") processes are of central importance in the astrophysics of neutron stars. Standard calculations approximate the Urca rate as the sum of two contributions, direct Urca and modified Urca. Attempts to make modified Urca calculations more accurate have been impeded by an unphysical divergence at the direct Urca threshold density. In this paper we describe a systematically improvable approach where, in the simplest approximation, instead of modified Urca we include an imaginary part of the nucleon mass (nucleon width). The total Urca rate is then obtained via a straightforward generalization of the direct Urca calculation, yielding results that agree with both direct and modified Urca at the densities where those approximations are valid. At low densities, we observe an enhancement of the rate by more than an order of magnitude, with important ramifications for neutron star cooling and other transport properties.
- [41] arXiv:2406.13737 (cross-list from hep-th) [pdf, html, other]
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Title: The Born regime of gravitational amplitudesComments: 35 pages + appendices, 6 figuresSubjects: High Energy Physics - Theory (hep-th); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Phenomenology (hep-ph)
We study the $2 \to 2$ scattering in the regime where the wavelength of the scattered objects is comparable to their distance but is much larger than any Compton wavelength in the quantum field theory. We observe that in this regime - which differs from the eikonal - the Feynman diagram expansion takes the form of a geometric series, akin to the Born series of quantum mechanics. Conversely, we can define the Feynman diagram expansion as the Born series of a relativistic effective-one-body (EOB) Schrödinger equation. For a gravitational theory in this regime we observe that the EOB Schrödinger equation reduces to the Regge-Wheeler or Teukolsky wave equations. We make use of this understanding to study the tree-level Compton scattering off a Kerr black hole. We compute the scalar and photon Compton amplitude up to $O(a^{30})$ in the black hole spin $a$ and propose an all-order expression. Remarkably, we find that boundary terms, which are typically neglected, give non-zero contact pieces necessary for restoring crossing symmetry and gauge invariance of the Kerr-Compton amplitude.
- [42] arXiv:2406.13738 (cross-list from hep-th) [pdf, other]
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Title: Abelian Instantons and Monopole ScatteringComments: 43 pages main text, 12 pages appendix, 4 figuresSubjects: High Energy Physics - Theory (hep-th); High Energy Physics - Phenomenology (hep-ph)
It is usually assumed that $4D$ instantons can only arise in non-Abelian theories. In this paper we re-examine this conventional wisdom by explicitly constructing instantons in an Abelian gauge theory: ${\rm QED}_4$ with $N_f$ flavors of Dirac fermions, in the background of a Dirac monopole. This is the low-energy effective field theory for fermions interacting with a 't Hooft-Polyakov monopole, in the limit where the monopole is infinitely heavy (hence pointlike) and static. This theory, whose non-topological sectors were studied by Rubakov and Callan, has a far richer structure than previously explored. We show how to calculate the topological instanton number, demonstrate the existence of 't Hooft zero modes localized around such instantons, and show how instantons in the path integral provide the underlying mechanism for the Callan-Rubakov process: monopole-catalyzed baryon decay with a cross section that saturates the unitarity bound. Our computation relies on correctly identifying the relevant $2D$ EFT for monopole catalysis as Axial ${\rm QED}_2$ in an effective $AdS_2$ metric.
- [43] arXiv:2406.14001 (cross-list from astro-ph.HE) [pdf, html, other]
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Title: High-energy Neutrino Emission from NGC 1068 by Outflow-cloud InteractionsComments: 7 Pages, 4 figures, 1 table; submittedSubjects: High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics - Phenomenology (hep-ph)
As the hottest high-energy neutrino spot, NGC 1068 has received much attention in recent years. Here we focus on the central region of the active galactic nuclei (AGN) and propose an outflow-cloud interaction model that could probably explain the observed neutrino data. Considering the accretion process adjacent to the central supermassive black hole (SMBH) of NGC 1068, strong outflows will be generated, which will likely interact with surrounding clouds floating in the corona region. Particles carried by the outflow will be accelerated to very high energy by the shocks forming during the outflow-cloud interactions. For the accelerated high-energy protons, $p\gamma$ interactions with the background photon field of the corona and disk and $pp$ interaction with the surrounding gas will produce considerable high-energy $\gamma$-rays and neutrino. However, because of the extremely dense photon fields in the corona and disk, the newly generated $\gamma$-rays will be significantly attenuated through the $\gamma\gamma$ absorptions. In our scenario, the expected GeV-TeV $\gamma$-ray emission will be suppressed to a much lower level than the neutrino emission, consistent with the observational characteristics of NGC 1068, while the generated 1-30\,TeV neutrino flux can fit the IceCube data very well.
- [44] arXiv:2406.14002 (cross-list from astro-ph.HE) [pdf, html, other]
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Title: A Collaborative Explanation of Cosmic Ray Spectrum Based on the Gluon Condensation ModelSubjects: High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics - Phenomenology (hep-ph)
Based on the Gluon Condensation (GC) model, the relationship between the spectra of electrons, $\gamma$ rays, and neutrinos in cosmic rays can be deduced. It has been found that these particles share the same parameter, $\beta_p$, and have an identical GC threshold values. This paper explores the connection between the second excess spectra of electron and the spectra of gamma rays and neutrinos. According to the observed gamma-ray data, it is suggested that the source LHAASO J2108+5157 might contribute to the second excess of electron.
- [45] arXiv:2406.14152 (cross-list from astro-ph.CO) [pdf, html, other]
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Title: Clocking the End of Cosmic InflationComments: 24 pages, 2 figures, uses jcappubSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Theory (hep-th)
Making observable predictions for cosmic inflation requires determining when the wavenumbers of astrophysical interest today exited the Hubble radius during the inflationary epoch. These instants are commonly evaluated using the slow-roll approximation and measured in e-folds $\Delta N=N-N_\mathrm{end}$, in reference to the e-fold $N_\mathrm{end}$ at which inflation ended. Slow roll being necessarily violated towards the end of inflation, both the approximated trajectory and $N_\mathrm{end}$ are determined at, typically, one or two e-folds precision. Up to now, such an uncertainty has been innocuous, but this will no longer be the case with the forthcoming cosmological measurements. In this work, we introduce a new and simple analytical method, on top of the usual slow-roll approximation, that reduces uncertainties on $\Delta N$ to less than a tenth of an e-fold.
- [46] arXiv:2406.14157 (cross-list from gr-qc) [pdf, html, other]
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Title: Exact solutions for differentially rotating galaxies in general relativityComments: 5 pages, 2 figuresSubjects: General Relativity and Quantum Cosmology (gr-qc); Cosmology and Nongalactic Astrophysics (astro-ph.CO); Astrophysics of Galaxies (astro-ph.GA); High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Theory (hep-th)
A class of stationary axisymmetric solutions of Einstein's equations for isolated differentially rotating dust sources is presented. The low-energy asymptotic regime is extracted, requiring a self-consistent coupling of quasilocal energy and angular momentum. The Raychaudhuri equation reduces to a balance equation, with two important limits. These limits can be interpreted empirically for rotationally supported configurations such as galaxies. The net energy including quasilocal kinetic contributions vanishes on the inner vortex surface, and the outer rotosurface. These new geometrical objects potentially shed light on virialization. Whether or not abundant collisionless dark matter exists, the new solutions suggest that the phenomenology of galactic rotation curves be fundamentally reconsidered, for consistency with general relativity.
- [47] arXiv:2406.14225 (cross-list from quant-ph) [pdf, html, other]
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Title: Comment on "Covariant quantum field theory of tachyons"Comments: 5 pages, 1 figure; comment to arXiv:2308.00450, which was accepted by PRDSubjects: Quantum Physics (quant-ph); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Theory (hep-th)
Recently, Paczos et al. (2308.00450) proposed a covariant quantum field theory for free and interacting tachyon fields. We show that the proposed Feynman propagator is not Lorentz invariant, proper asymptotic (in/out) tachyon states do not exist, and the proposed S-matrix describing interactions of tachyons and subluminal matter is ill-defined. Since tachyons behave as bosons, interacting tachyons may also self-interact, e.g., any interaction with ordinary matter generates such terms. As a result, the physical vacuum, instead of being at the origin of the potential, may correspond to the proper minimum of the tachyon potential, or such state does not exist at all. Our analysis indicates that quantum tachyon field does not describe a physical on-shell particle with negative mass squared.
- [48] arXiv:2406.14357 (cross-list from hep-th) [pdf, html, other]
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Title: Black holes with electroweak hairComments: 5+8 pages, 5+1 figuresSubjects: High Energy Physics - Theory (hep-th); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Phenomenology (hep-ph)
We construct static and axially symmetric magnetically charged hairy black holes in the gravity-coupled Weinberg-Salam theory. Large black holes merge with the Reissner-Nordström (RN) family, while the small ones are extremal and support a hair in the form of a ring-shaped electroweak condensate carrying superconducting W-currents and up to $22\%$ of the total magnetic charge. The extremal solutions are asymptotically RN with a mass {\it below} the total charge, $M<|Q|$, due to the negative Zeeman energy of the condensate interacting with the black hole magnetic field. Therefore, they cannot decay into RN black holes. As their charge increases, they show a phase transition when the horizon symmetry changes from spherical to oblate. At this point they have the mass typical for planetary size black holes of which $\approx 11\%$ are stored in the hair. Being obtained within a well-tested theory, our solutions are expected to be physically relevant.
- [49] arXiv:2406.14419 (cross-list from hep-th) [pdf, html, other]
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Title: Spin Statistics and Surgeries of Topological Solitons in QCD Matter in Magnetic FieldComments: 38 pages, 8 figuresSubjects: High Energy Physics - Theory (hep-th); High Energy Physics - Phenomenology (hep-ph)
The ground state of QCD with two flavors (up and down quarks) at finite baryon density in sufficiently strong magnetic field is in a form of either a chiral soliton lattice(CSL), an array of solitons stacked along the magnetic field, or a domain-wall Skyrmion phase in which Skyrmions are spontaneously created on top of the CSL In the latter, one 2D (baby) Skyrmion in the chiral soliton corresponds to two 3D Skyrmions (baryons) in the bulk. In this paper, we study spin statistics of topological solitons by using the following two methods: the conventional Witten's method by embedding the pion fields of two flavors into those of three flavors with the Wess-Zumino-Witten (WZW) term, and a more direct method by using the two-flavor WZW term written in terms of a spin structure. We find that a chiral soliton of finite quantized size called a pancake soliton and a hole on a chiral soliton are fermions or bosons depending on odd or even quantizations of their surface areas, respectively, and a domain-wall Skyrmion is a boson. We also propose surgeries of topological solitons: a domain-wall Skyrmion (boson) can be cut into a pancake soliton (fermion) and a hole (fermion), and a chiral soliton without Skyrmions can be cut into a pancake soliton (fermion) and a hole (fermion).
- [50] arXiv:2406.14554 (cross-list from astro-ph.CO) [pdf, html, other]
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Title: Neutrino mass bounds from DESI 2024 are relaxed by Planck PR4 and cosmological supernovaeComments: 5 pages, 3 figures, 2 tables, plus appendicesSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Phenomenology (hep-ph)
The recent DESI 2024 Baryon Acoustic Oscillations (BAO) measurements combined with the CMB data from the Planck 18 PR3 dataset and the Planck PR4+ACT DR6 lensing data, with a prior on the sum of the neutrino masses $\sum m_\nu>0$, leads to a strong constraint, $\sum m_\nu<0.072$ eV, which would exclude the inverted neutrino hierarchy and put some tension on even the standard hierarchy. We show that actually this bound gets significantly relaxed when combining the new DESI measurements with the HiLLiPoP+LoLLiPoP likelihoods, based on the Planck 2020 PR4 dataset, and with supernovae datasets. We note that the fact that neutrino masses are pushed towards zero, and even towards negative values, is known to be correlated with the so-called $A_L$ tension, a mismatch between lensing and power spectrum measurements in the Planck PR3 data, which is reduced by HiLLiPoP+LoLLiPoP to less than 1$\sigma$. We find $\sum m_\nu<0.1$ eV and $\sum m_\nu<0.12$ eV, with the supernovae Pantheon+ and DES-SN5YR datasets respectively. The shift caused by these datasets is more compatible with the expectations from neutrino oscillation experiments, and both the normal and inverted hierarchy scenarios remain now viable, even with the $\sum m_\nu>0$ prior. Finally, we analyze neutrino mass bounds in an extension of $\Lambda$CDM that addresses the $H_0$ tension, with extra fluid Dark Radiation, finding that in such models bounds are further relaxed and the posterior probability for $\sum m_\nu$ begins to exhibit a peak at positive values.
Cross submissions for Friday, 21 June 2024 (showing 22 of 22 entries )
- [51] arXiv:2012.13946 (replaced) [pdf, html, other]
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Title: Broadband Dark Matter Axion Detection using a Cylindrical CapacitorComments: 9 pages, 9 figures, 2 tables; matches published versionJournal-ref: Nucl. Phys. B 1005 (2024) 116602Subjects: High Energy Physics - Phenomenology (hep-ph); Instrumentation and Methods for Astrophysics (astro-ph.IM); High Energy Physics - Experiment (hep-ex)
Cosmological axions/axion-like particles can compose a significant part of dark matter; however, the uncertainty of their mass is large. Here, we propose to search the axions using a cylindrical capacitor, in which the static electric field converts dark matter axions into an oscillating magnetic field. Due to the odd CPs, the axions couple to the electric field differently compared to the magnetic field. The axion couples to the electric field via a derivative that carries spatial information of incoming dark matter flux, while the coupling to the magnetic field depends on the dark matter density. This difference could be helpful in searching the axions and studies of the integrity of the theory, especially when the axions are very light, in which case the magnetic field-induced signal is DC-like. Orientation dependence could also be used to reduce the kinetic fluctuation-induced noise when multiple detectors operate simultaneously. In addition, a cylindrical setup shields the electric field to the laboratory and encompasses the axion-induced magnetic field within the capacitor. The induced oscillating magnetic field can then be picked up by a sensitive magnetometer. Adding a superconductor ring-coil system into the scheme can further boost the sensitivity and maintain the axion dark matter inherent bandwidth. This proposed setup could be capable of wide mass range searches.
- [52] arXiv:2107.10829 (replaced) [pdf, html, other]
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Title: High-energy $\pi\pi$ scattering without and with photon radiationComments: 57 pages, 20 figures, v3 is a final version including corrections from the published ErratumJournal-ref: Phys.Rev.D 105 (2022) 014022; Erratum: Phys.Rev.D 109 (2024) 099901Subjects: High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Experiment (hep-ex)
We discuss the processes $\pi \pi \to \pi \pi$ and $\pi \pi \to \pi \pi \gamma$ from a general quantum field theory (QFT) point of view. We study the soft-photon limit where the photon energy $\omega \to 0$ and where we have the theorems due to F.E. Low and S. Weinberg. We consider for the radiative amplitude the Laurent expansion in $\omega$ and calculate the terms of order $\omega^{-1}$ and $\omega^{0}$. The pole term $\propto \omega^{-1}$ is given by Weinberg's soft-photon theorem. Then we calculate the amplitudes for the above reactions for high center-of-mass energies and small momentum transfers, that is, in the soft-diffraction regime using the tensor-pomeron model. We identify places where "anomalous" soft photons could come from. Three soft-photon approximations (SPAs) are introduced. The corresponding SPA results are compared to those obtained from the full tensor-pomeron model for center-of-mass energies $\sqrt{s} = 10$ GeV and 100 GeV. The kinematic regions where the SPAs are a good representation of the full amplitude are determined. Finally we make some remarks on the type of fundamental information one could obtain from high-energy exclusive hadronic reactions without and with soft photon radiation.
- [53] arXiv:2202.09217 (replaced) [pdf, html, other]
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Title: Indirect search of Heavy Neutral Leptons using the DUNE Near DetectorComments: 11 pages, 13 figures; the chi2 is now calculated by comparing the neutrino CC spectra instead of the total CC eventsJournal-ref: Frontiers in Physics 12 (2024)Subjects: High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Experiment (hep-ex)
We evaluate the potential of the DUNE Near Detector (DUNEND) for establishing bounds for heavy neutral leptons (HNL). This is achieved by studying how the presence of HNLs affects the production rates of active neutrinos, therefore, creating a deficit in the neutrino charged current (CC) events at the LArTPC of the DUNEND. The estimated bounds on HNLs are calculated for masses between 1 eV and 500 MeV. We consider 10 years of operation (5 in neutrino and antineutrino mode) and obtain limits of $|U_{\mu4}|^2 < 9 \times 10^{-3} (4 \times10^{-2})$ and $|U_{e4}|^2 < 7\times10^{-3} (3 \times10^{-2})$ for masses below 10 MeV and a 5\%(20\%) overall normalization uncertainty in the neutrino charged current event rates prediction. These limits, within the region of masses below 2(10) MeV, are better than those that can be achieved by DUNE direct searches for the case of a 5\%(20\%) uncertainty. When a conservative 20\% uncertainty is present, our limits can only improve current constraints on $|U_{e4}|^2$ by up to a factor of 3 in a small region around 5 eV and set limits on $|U_{\mu4}|^2$ in a mass region free of constraints (40 eV - 1 MeV).
- [54] arXiv:2204.00564 (replaced) [pdf, html, other]
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Title: Reach and complementarity of $\mu\to e$ searchesComments: some typos corrected; version accepted for publicationSubjects: High Energy Physics - Phenomenology (hep-ph)
In Effective Field Theory, we describe $\mu\leftrightarrow e$ flavour changing transitions using an operator basis motivated by experimental observables. In a six-dimensional subspace probed by $\mu \to e \gamma$, $\mu \to 3e$ and $\mu\to e$ conversion on nuclei, we derive constraints on the New Physics scale from past and future experiments, illustrating the complementarity of the processes in an intuitive way. We also recall that a precise determination of the scalar quark currents in the nucleon will be required to distinguish scalar $\mu\to e$ interactions on u-quarks from those on d-quarks.
- [55] arXiv:2209.14309 (replaced) [pdf, html, other]
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Title: Symmetry energy in holographic QCDComments: LaTeX: 29 pages, 5 figures; V2: extended version; V3: comments, references and appendices C through E addedJournal-ref: SciPost Phys. 16, 156 (2024)Subjects: High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Theory (hep-th); Nuclear Theory (nucl-th)
We study the symmetry energy (SE), an important quantity in nuclear physics, in the Witten-Sakai-Sugimoto model and in a much simpler hard-wall model of holographic QCD. The SE is the energy contribution to the nucleus due to having an unequal number of neutrons and protons. Using a homogeneous Ansatz representing smeared instantons and quantizing their isospin, we extract the SE and the proton fraction assuming charge neutrality and beta-equilibrium, using quantization of the isospin zeromode. We also show the equivalence between our method adapted from solitons and the usual way of the isospin controlled by a chemical potential at the holographic boundary. We find that the SE can be well described in the WSS model if we allow for a larger 't Hooft coupling and lower Kaluza-Klein scale than is normally used in phenomenological fits.
- [56] arXiv:2301.07036 (replaced) [pdf, html, other]
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Title: EFT analysis of New Physics at COHERENTComments: 52 pages, 7 figures, 3 tables, typos correctedSubjects: High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Experiment (hep-ex)
Using an effective field theory approach, we study coherent neutrino scattering on nuclei, in the setup pertinent to the COHERENT experiment. We include non-standard effects both in neutrino production and detection, with an arbitrary flavor structure, with all leading Wilson coefficients simultaneously present, and without assuming factorization in flux times cross section. A concise description of the COHERENT event rate is obtained by introducing three generalized weak charges, which can be associated (in a certain sense) to the production and scattering of $\nu_e$, $\nu_\mu$ and $\bar{\nu}_\mu$ on the nuclear target. Our results are presented in a convenient form that can be trivially applied to specific New Physics scenarios. In particular, we find that existing COHERENT measurements provide percent level constraints on two combinations of Wilson coefficients. These constraints have a visible impact on the global SMEFT fit, even in the constrained flavor-blind setup. The improvement, which affects certain 4-fermion LLQQ operators, is significantly more important in a flavor-general SMEFT. Our work shows that COHERENT data should be included in electroweak precision studies from now on.
- [57] arXiv:2304.10779 (replaced) [pdf, html, other]
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Title: eHIJING: an Event Generator for Jet Tomography in Electron-Ion CollisionsComments: 32 pages, 35 figuresSubjects: High Energy Physics - Phenomenology (hep-ph)
We develop the first event generator, the electron-Heavy-Ion-Jet-INteraction-Generator (eHIJING), for the jet tomography study of electron-ion collisions. In this generator, energetic jet partons produced from the initial hard scattering undergo multiple collisions with the nuclear target. The collision rate is proportional to the transverse-momentum-dependent (TMD) gluon density in the nucleus, which is given by a simple model inspired by the physics of gluon saturation. Medium-modified QCD splitting functions within the higher-twist (HT) and generalized higher-twist (GHT) frameworks are utilized to simulate parton showering in the nuclear medium that takes into account the non-Abelian Landau-Pomeranchuck-Midgal interference effect. Employing eHIJING, we revisit hadron production in semi-inclusive deep inelastic scattering (SIDIS) as measured by EMC, HERMES, and recent CLAS experiments. eHIJING with both GT and GHT frameworks gives reasonably good descriptions of these experimental data. Predictions for experiments at the future electron-ion colliders are also provided. It is demonstrated that future measurements of the transverse momentum broadening of single hadron spectra can be used to map out the two-dimensional kinematic ($Q^2, x_B$) dependence of the jet transport coefficient $\hat{q}$ in cold nuclear matter.
- [58] arXiv:2307.09595 (replaced) [pdf, html, other]
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Title: Gauge $SU(2)_f$ flavour transfersComments: 50 pages, 8 figures, 1 table. References addedJournal-ref: JHEP 05 (2024) 313Subjects: High Energy Physics - Phenomenology (hep-ph)
We introduce the idea of flavour transfer from a non-abelian horizontal $SU(2)_f$ flavour gauge group embedded in the Standard Model flavour structure. The new flavour vector bosons, in the mass range from the tens of GeV to multi-TeV do not induce large flavour-changing currents and meson oscillations, which usually provide the dominant constraints on this type of structure. Instead, the dominant constraints arise from "flavour-transfer" operators that we will study in details. Several explicit models are presented and their prospects are thoroughly explored, including their phenomenology in the lepton and quark sectors at colliders and lower energy experiments. We finally perform a complete numerical fit in one such scenario, showing that LHC-based lepton-flavour violating searches are competitive with intensity frontier observables.
- [59] arXiv:2309.15602 (replaced) [pdf, html, other]
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Title: Dispersive determination of fourth generation quark massesComments: 12 pages, 5 figures, version to appear in PRDSubjects: High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Experiment (hep-ex)
We determine the masses of the sequential fourth generation quarks $b'$ and $t'$ in the extension of the Standard Model by solving the dispersion relations associated with the mixing between the neutral states $Q\bar q$ and $\bar Qq$, $Q$ ($q$) being a heavy (light) quark. The box diagrams responsible for the mixing, which provide the perturbative inputs to the dispersion relations, involve multiple intermediate channels, i.e., the $ut$ and $ct$ channels, $u$ ($c$, $t$) being an up (charm, top) quark, in the $b'$ case, and the $db'$, $sb'$ and $bb'$ ones, $d$ ($s$, $b$) being a down (strange, bottom) quark, in the $t'$ case. The common solutions for the above channels lead to the masses $m_{b'}=(2.7\pm 0.1)$ TeV and $m_{t'}\approx 200$ TeV unambiguously. We show that these superheavy quarks, forming bound states in a Yukawa potential, barely contribute to Higgs boson production via gluon fusion and decay to photon pairs, and bypass current experimental constraints. The mass of the $\bar b'b'$ ground state is estimated to be about 3.2 TeV. It is thus worthwhile to continue the search for $b'$ quarks or $\bar b'b'$ resonances at the (high-luminosity) large hadron collider.
- [60] arXiv:2312.02278 (replaced) [pdf, html, other]
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Title: Learning PDFs through Interpretable Latent Representations in Mellin SpaceComments: 22 pages, 11 figures; updated link to public code, this https URLSubjects: High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Lattice (hep-lat); Nuclear Theory (nucl-th)
Representing the parton distribution functions (PDFs) of the proton and other hadrons through flexible, high-fidelity parametrizations has been a long-standing goal of particle physics phenomenology. This is particularly true since the chosen parametrization methodology can play an influential role in the ultimate PDF uncertainties as extracted in QCD global analyses; these, in turn, are often determinative of the reach of experiments at the LHC and other facilities to non-standard physics, including at large $x$, where parametrization effects can be significant. In this study, we explore a series of encoder-decoder machine-learning (ML) models with various neural-network topologies as efficient means of reconstructing PDFs from meaningful information stored in an interpretable latent space. Given recent effort to pioneer synergies between QCD analyses and lattice-gauge calculations, we formulate a latent representation based on the behavior of PDFs in Mellin space, i.e., their integrated moments, and test the ability of various models to decode PDFs from this information faithfully. We introduce a numerical package, $\texttt{PDFdecoder}$, which implements several encoder-decoder models to reconstruct PDFs with high fidelity and use this tool to explore strengths and pitfalls of neural-network approaches to PDF parametrization. We additionally dissect patterns of learned correlations between encoded Mellin moments and reconstructed PDFs which suggest opportunities for further improvements to ML-based approaches to PDF parametrizations and uncertainty quantification.
- [61] arXiv:2401.13101 (replaced) [pdf, html, other]
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Title: Singlet Dirac dark matter streamlinedComments: 19 pages, 11 figures; v2: journal versionSubjects: High Energy Physics - Phenomenology (hep-ph)
We propose a new and compact realization of singlet Dirac dark matter within the WIMP framework. Our model replaces the standard $Z_2$ stabilizing symmetry with a $Z_6$, and uses spontaneous symmetry breaking to generate the dark matter mass, resulting in a much simplified scenario for Dirac dark matter. Concretely, we extend the Standard Model (SM) with just two new particles, a Dirac fermion (the dark matter) and a real scalar, both charged under the $Z_6$ symmetry. After acquiring a vacuum expectation value, the scalar gives mass to the dark matter and mixes with the Higgs boson, providing the link between the dark sector and the SM particles. With only four free parameters, this new model is extremely simple and predictive. We study the dark matter density as a function of the model's free parameters and use a likelihood approach to determine its viable parameter space. Our results demonstrate that the dark matter mass can be as large as $6$ TeV while remaining consistent with all known theoretical and experimental bounds. In addition, a large fraction of viable models turns out to lie within the sensitivity of future direct detection experiments, furnishing a promising way to test this appealing scenario.
- [62] arXiv:2401.13393 (replaced) [pdf, html, other]
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Title: Effect of continuum states on the double-heavy hadron spectraComments: 20 pages, 4 figures, Journal versionSubjects: High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Experiment (hep-ex); High Energy Physics - Lattice (hep-lat)
We present the leading order coupling of double-heavy hadrons to heavy hadron pairs in Born-Oppenheimer effective field theory. We obtain the expressions for the contribution of heavy hadron pairs to the masses and widths of double-heavy hadrons. We apply our result for the specific case of the coupling of the lowest lying heavy hybrids and $D_{(s)}^{(*)}\bar{D}_{(s)}^{(*)}(B_{(s)}^{(*)}\bar{B}_{(s)}^{(*)})$ obtaining a set of selection rules for the decays. We build a model for the coupling potential and compute the corresponding decay widths and the contributions to the mass of the heavy hybrids. We compare our results with the experimental exotic quarkonium spectrum and discuss the most likely experimental candidates for quarkonium hybrids.
- [63] arXiv:2401.14917 (replaced) [pdf, html, other]
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Title: Direct WIMP detection rates for transitions in isomeric nucleiSubjects: High Energy Physics - Phenomenology (hep-ph); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
The direct detection of dark matter constituents, in particular the weakly interacting massive particles (WIMPs), is central to particle physics and cosmology. In this paper we study WIMP induced transitions from isomeric nuclear states for two possible isomeric candidates: $\rm^{180}Ta$ and $\rm^{166}Ho$. The experimental setup, which can measure the possible decay of $\rm^{180}Ta$ induced by WIMPs, was proposed. The corresponding estimates of the half-life of $\rm^{180}Ta$ are given in the sense that the WIMP-nucleon interaction can be interpreted as ordinary radioactive decay.
- [64] arXiv:2401.17365 (replaced) [pdf, html, other]
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Title: Polarized ZZ pairs in gluon fusion and vector boson fusion at the LHCComments: Published version: additional discussion, results, and references. 16 pages, 6 figures, FeynRules UFO available from this https URL, mg5amc configuration files available from this https URLJournal-ref: Phys. Lett. B 855 (2024) 138787Subjects: High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Experiment (hep-ex)
Pair production of helicity-polarized weak bosons $(V_\lambda=W^\pm_\lambda, Z_\lambda)$ from gluon fusion $(gg\to V_\lambda V'_{\lambda'})$ and weak boson fusion $(V_1V_2\to V_\lambda V'_{\lambda'})$ are powerful probes of the Standard Model, new physics, and properties of quantum systems. Measuring cross sections of polarized processes is a chief objective of the Large Hadron Collider's (LHC) Run 3 and high luminosity programs, but progress is limited by the simulation tools that are presently available. We propose a method for computing polarized cross sections that works by directly modifying Feynman rules instead of (squared) amplitudes. The method is applicable to loop-induced processes, and can capture the interference between arbitrary polarization configurations, interference with non-resonant diagrams, as well as off-shell/finite-width effects. By construction, previous results that work at the (squared) amplitude level are recoverable. As a demonstration, we report the prospect of observing and studying polarized $Z_\lambda Z_{\lambda'}$ pairs when produced via gluon fusion and electroweak processes in final-states with four charged leptons at the LHC, using the new method to simulate the gluon fusion process. Our Feynman rules are publicly available as a set of \textit{Universal FeynRules Object} libraries called \texttt{SM\_Loop\_VPolar}.
- [65] arXiv:2402.15088 (replaced) [pdf, html, other]
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Title: Hyperon semileptonic decays in QCD sum rulesComments: 18 pages, 2 figuresSubjects: High Energy Physics - Phenomenology (hep-ph)
We investigate the hyperon semileptonic decays within the framework of QCD sum rules. The flavor $ SU(3) $ symmetry breaking effects are analyzed via the relevant form factors and corresponding branching fractions. Employing the $ z $-series parameterization to capture the $ q^2 $ dependence of form factors, we calculate the hyperon semileptonic decay rates and confront them with the recent experimental measurements. Moreover, we calculate as well the non-standard tensor form factors, which involve certain new physics beyond the standard model.
- [66] arXiv:2403.06133 (replaced) [pdf, html, other]
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Title: Transverse polarization of Lambda hyperons in hadronic collisionsComments: 13 pages, 15 figuresSubjects: High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Experiment (hep-ex); Nuclear Theory (nucl-th)
The transverse polarization of $\Lambda$ hyperon within reconstructed jets in hadronic collisions offers a complementary platform to probe the polarized fragmentation function $D_{1T}^\perp$. We illustrate that by performing a global analysis of the transverse polarization of $\Lambda$ hyperons produced in different kinematic regions and in different hadronic collisions, such as $pp$, $p\bar p$, $pA$, and $\gamma A$ collisions, we can pin down the flavor dependence of $D_{1T}^\perp$ which has been poorly constrained. Besides the single inclusive jet production, the $\gamma/Z^0$-boson associated jet production supplements with more capability in removing ambiguities in the flavor dependence of $D_{1T}^\perp$.
- [67] arXiv:2403.16623 (replaced) [pdf, html, other]
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Title: Direct Production of Light Scalar in the Type-I Two-Higgs-Doublet Model at the Lifetime Frontier of LHCComments: 14 pages+refs, 7 figures, to be published in PRDSubjects: High Energy Physics - Phenomenology (hep-ph)
A light pseudoscalar $A$ in the sufficient large $\tan\beta$ region of type-I two-Higgs-doublet model (2HDM) can be naturally a long-lived particle (LLP). We focus on $H^{\pm}A$, $HA$ and $AA$ pair productions via the electroweak processes mediated by the bosons at the LHC, including $pp \rightarrow W^\pm/Z \rightarrow H^{\pm}/H A$ and $pp \rightarrow h \rightarrow AA$ at the 14 TeV LHC. The possibility of probing $A$ as a LLP at the FASER-2, FACET, MoEDAL-MAPP-2, MATHUSLA is discussed. We find that FASER-2 fails to probe any parameter space within 0.2 GeV $< m_A <$ 10 GeV for all the considered processes. For 130 $< m_{H\pm} = m_H <$ 400 GeV, FACET, MoEDAL-MAPP-2 and MATHUSLA can probe $\tan \beta \lesssim 10^{4-6}$ for $m_A \lesssim 3$ GeV, and $\tan \beta \lesssim 10^{6-8}$ for 3 GeV $\lesssim m_A <$ 10 GeV from $pp \rightarrow W^\pm/Z \rightarrow H^{\pm}/Z A$ processes. And $pp \rightarrow h \rightarrow AA$ process covers similar parameter space. All processes can surpass the current limits.
- [68] arXiv:2404.02085 (replaced) [pdf, html, other]
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Title: On the model uncertainties for the predicted muon content of extensive air showersComments: Version accepted for Astroparticle PhysicsSubjects: High Energy Physics - Phenomenology (hep-ph); High Energy Astrophysical Phenomena (astro-ph.HE)
Motivated by the excess of the muon content of cosmic ray induced extensive air showers (EAS), relative to EAS modeling, observed by the Pierre Auger Observatory, and by the tension between Auger data and air shower simulations on the maximal muon production depth $X^{\mu}_{\max}$, we investigate the possibility to modify the corresponding EAS simulation results, within the Standard Model of particle physics. We start by specifying the kinematic range for secondary hadron production, which is of relevance for such predictions. We further investigate the impact on the predicted EAS muon number and on $X^{\mu}_{\max}$ of various modifications of the treatment of hadronic interactions, in the framework of the QGSJET-III model, in particular the model calibration to accelerator data, the amount of the "glue" in the pion, and the energy dependence of the pion exchange process. None of the considered modifications of the model allowed us to enhance the EAS muon content by more than 10\%. On the other hand, for the maximal muon production depth, some of the studied modifications of particle production give rise up to $\sim 10$ g/cm$^2$ larger $X^{\mu}_{\max}$ values, which increases the difference with Auger observations.
- [69] arXiv:2404.04826 (replaced) [pdf, html, other]
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Title: Two-photon production of $f_0$ and $a_0$ resonances as hadronic molecules composed of two vector mesonsLi-Ke Yang (1 and 2), Zheng-Li Wang (2), Jia-Jun Wu (2), Bing-Song Zou (3, 1, 2) ((1) CAS Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing, China, (2) School of Physics, University of Chinese Academy of Sciences (UCAS), Beijing, China, (3) Department of Physics, Tsinghua University, Beijing, China)Subjects: High Energy Physics - Phenomenology (hep-ph)
Ascribed as $\rho\rho$ and $K^* \bar{K}^*$ molecular states, respectively, iso-scalar $f_0(1500)$ and $f_0(1710)$ states are expected to have iso-vector partners, potentially identified as $a_0(1450)$ and $a_0(1710)$. The predicted dominant decay modes for these two $a_0$ resonances are $a_0(1450) \to \omega\pi\pi$ and $a_0(1710) \to \omega\pi\pi,\,\phi\pi\pi$. We estimate cross sections for two-photon production of these four resonances within the hadronic molecular picture, and demonstrate that SuperKEKB's luminosity is sufficient for their observation and more precise parameter measurements.
- [70] arXiv:2404.08598 (replaced) [pdf, html, other]
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Title: Next-to-next-to-leading order event generation for Z-boson production in association with a bottom-quark pairComments: 5 pages + supplementary material, 2 figures, 2 tablesSubjects: High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Experiment (hep-ex)
We consider the production of a Z boson decaying to leptons in association with a bottom-quark pair in hadronic collisions. For the first time, we compute predictions at next-to-next-to-leading order (NNLO) in QCD, and we combine them with the all-orders radiative corrections from a parton-shower simulation (NNLO+PS). Our method represents the first approach to NNLO+PS event generation applicable to processes featuring a colour singlet and a heavy-quark pair in the final state. The novel two-loop corrections are computed for massless bottom quarks, and the leading mass corrections are restored through a small-mass expansion. The calculation is carried out in the four-flavour scheme, and we find that the sizeable NNLO QCD corrections lift the long-standing tension between lower-order predictions in four- and five-flavour schemes. Our predictions are compared to a CMS measurement for Z boson plus b-jet production, achieving an excellent description of the data.
- [71] arXiv:2404.12654 (replaced) [pdf, html, other]
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Title: Semileptonic $\Omega_{b}\rightarrow \Omega_{c}{\ell}\bar\nu_{\ell}$ transition in full QCDComments: 19 Pages, 9 Figures and 5 TablesSubjects: High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Experiment (hep-ex); High Energy Physics - Lattice (hep-lat)
We investigate the semileptonic decay of $\Omega_b\to\Omega_c~{\ell}\bar\nu_{\ell}$ in three lepton channels. To this end, we use QCD sum rule method in three point framework to calculate the form factors defining the matrix elements of these transitions. Having calculated the form factors as building blocks, we calculate the decay widths and branching fractions of the exclusive decays in all lepton channels and compare the results with other theoretical predictions. The obtained results for branching ratios and ratio of branching fractions at different leptonic channels may help experimental groups in their search for these weak decays. Comparison of the obtained results with possible future experimental data can be useful to check the order of consistency between the standard model theory predictions and data on the heavy baryon decays.
- [72] arXiv:2404.13814 (replaced) [pdf, html, other]
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Title: Discovering Quirks through Timing at FASER and Future Forward Experiments at the LHCComments: 29 pages, 11 figures, version to appear in JHEPSubjects: High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Experiment (hep-ex)
Quirks are generic predictions of strongly-coupled dark sectors. For weak-scale masses and a broad range of confining scales in the dark sector, quirks can be discovered only at the energy frontier, but quirk--anti-quirk pairs are produced with unusual signatures at low $p_T$, making them difficult to detect at the large LHC detectors. We determine the prospects for discovering quirks using timing information at FASER, FASER2, and an "ultimate detector" in the far-forward region at the LHC. NLO QCD corrections are incorporated in the simulation of quirk production, which can significantly increase the production rate. To accurately propagate quirk pairs from the ATLAS interaction point to the forward detectors, the ionization energy loss of charged quirks traveling through matter, the radiation of infracolor glueballs and QCD hadrons during quirk pair oscillations, and the annihilation of quirkonium are properly considered. The quirk signal is separated from the large muon background using timing information from scintillator detectors by requiring either two coincident delayed tracks, based on arrival times at the detector, or two coincident slow tracks, based on time differences between hits in the front and back scintillators. We find that simple cuts preserve much of the signal, but reduce the muon background to negligible levels. With the data already collected, FASER can discover quirks in currently unconstrained parameter space. FASER2, running at the Forward Physics Facility during the HL-LHC era, will greatly extend this reach, probing the TeV-scale quirk masses motivated by the gauge hierarchy problem for the broad range of dark-sector confining scales between 100 eV and 100 keV.
- [73] arXiv:2405.00094 (replaced) [pdf, html, other]
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Title: How to rule out $(g-2)_\mu$ in $U(1)_{L_\mu-L_\tau}$ with White Dwarf CoolingComments: 17 pages, 6 figures, 2 data files; v2: improved discussion of the cooling limit, matches journal version to appear in JHEPSubjects: High Energy Physics - Phenomenology (hep-ph)
In recent years, the gauge group $U(1)_{L_\mu-L_\tau}$ has received a lot of attention since it can, in principle, account for the observed excess in the anomalous muon magnetic moment $(g-2)_\mu$, as well as the Hubble tension. Due to unavoidable, loop-induced kinetic mixing with the SM photon and $Z$, the $U(1)_{L_\mu-L_\tau}$ gauge boson $A'$ can contribute to stellar cooling via decays into neutrinos. In this work, we perform for the first time an \textit{ab initio} computation of the neutrino emissivities of white dwarf stars due to plasmon decay in a model of gauged $U(1)_{L_\mu-L_\tau}$. A key result is that current observations of the early-stage white dwarf neutrino luminosity at the 30\% level exclude previously allowed regions of the parameter space favoured by a simultaneous explanation of the $(g-2)_\mu$ and $H_0$ anomalies. In this work, we present the relevant white dwarf cooling limits over the entire $A'$ mass range. In particular, we have performed a rigorous computation of the luminosities in the resonant regime, where the $A'$ mass is comparable to the white dwarf plasma frequencies.
- [74] arXiv:2405.04681 (replaced) [pdf, html, other]
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Title: Onset of scaling violation in pion and kaon elastic electromagnetic form factorsComments: 8 pages, 5 figures, 1 tableSubjects: High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Experiment (hep-ex); High Energy Physics - Lattice (hep-lat); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
Using a symmetry-preserving truncation of the quantum field equations describing hadron properties, parameter-free predictions are delivered for pion and kaon elastic electromagnetic form factors, $F_{P=\pi,K}$, thereby unifying them with kindred results for nucleon elastic electromagnetic form factors. Regarding positive-charge states, the analysis stresses that the presence of scaling violations in QCD entails that $Q^2 F_P(Q^2)$ should exhibit a single maximum on $Q^2>0$. Locating such a maximum is both necessary and sufficient to establish the existence of scaling violations. The study predicts that, for charged $\pi$, $K$ mesons, the $Q^2 F_P(Q^2)$ maximum lies in the neighbourhood $Q^2 \simeq 5\,$GeV$^2$. Foreseeable experiments will test these predictions and, providing their $Q^2$ reach meets expectations, potentially also provide details on the momentum dependence of meson form factor scaling violation.
- [75] arXiv:2405.05653 (replaced) [pdf, html, other]
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Title: On supposed oscillations of differential cross sections in pp-scattering at sqrt{s} = 13 TeVComments: 9 pages, 5 figuresSubjects: High Energy Physics - Phenomenology (hep-ph)
The question of possible existence of oscillations in the region of the diffraction peak in pp-scattering is considered in detail at sqrt{s}=13 TeV. It is shown that within the framework of the available experimental data published by the TOTEM and ALFA/ATLAS collaborations, raising the question of searching for such a subtle effect looks premature.
- [76] arXiv:2405.12692 (replaced) [pdf, html, other]
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Title: EW one-loop corrections to the longitudinally polarized Drell-Yan process. Charged-current case IIS. Bondarenko (1,5), Ya. Dydyshka (2,3,5), L. Kalinovskaya (2,4), A. Kampf (2,4), R. Sadykov (2), V. Yermolchyk (2,3,5) ((1) Bogoliubov Laboratory of Theoretical Physics, Joint Institute for Nuclear Research, Dubna, Russia, (2) Dzhelepov Laboratory of Nuclear Problems, Joint Institute for Nuclear Research, Dubna, Russia, (3) The Institute for Nuclear Problems, Belarusian State University, Minsk, Belarus, (4) Lomonosov Moscow State University, Moscow 119991, Russia, (5) Dubna State University, Dubna 141980, Russia)Subjects: High Energy Physics - Phenomenology (hep-ph)
Complete one-loop electroweak radiative corrections to the charged-current Drell-Yan processes $pp \to \ell^{+}\nu_{\ell}(+X)$ and $pp \to \ell^{-}\bar{\nu}_{\ell}(+X)$ are presented for the case of longitudinal polarization of initial particles. The results can be used to obtain precise predictions for the kinematic distributions of polarized $W^{\pm}$ production cross sections, and polarized single- and double-spin asymmetries. Numerical results are obtained using the Monte-Carlo generator ReneSANCe. This study is a contribution to the research program of the STAR and PHENIX collaborations in experiments of RHIC.
- [77] arXiv:2406.03440 (replaced) [pdf, other]
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Title: Analysis of experimental data on neutron decay for the possibility of the existence of a right vector boson $W_R$Comments: 6 pages, 6 figuresSubjects: High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Experiment (hep-ex)
Due to the assumption that sterile neutrinos are right-handed neutrinos, an analysis of the modern experimental situation in neutron decay for right-handed currents was carried out. As a result of the analysis, it was found that there are indications of the existence of a right-handed vector boson $W_R$ with a mass $M_{W_R}\approx 870_{-140}^{+260} \text{GeV}$ and a mixing angle with $W_L$: $\zeta=0.061_{-0.024}^{+0.017}$. This circumstance is the basis for discussing the possibility of expanding the Standard Model with an additional gauge vector boson $W_R$ and right-handed neutrinos.
- [78] arXiv:2406.08313 (replaced) [pdf, html, other]
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Title: Searching for bound states in the open strangeness systemsComments: More comments addedSubjects: High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Experiment (hep-ex)
Inspired by the recent findings of $Z_{cs}$ and $P_{cs}$ states, we investigate the strong interactions of the systems with open strangeness(es) from the light sector to the heavy sector (no beauty quark), where the interaction potential is derived from the vector meson exchange mechanism in $t$- and $u$-channels. In the current work, we discuss all of single channel cases for the open strangeness in the systemic framework, where the resonances $X_0(2866)$, $D^*_{s0}(2317)$ and $D_{s1}(2460)$ are dynamically generated. Furthermore, there are many new exotics predicted. In addition, the left-hand cut problem in $t$- and $u$-channels is discussed in detail.
- [79] arXiv:2105.13481 (replaced) [pdf, html, other]
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Title: Hyperon Polarization from the Vortical Fluid in Low Energy Nuclear CollisionsComments: 5 pages, 4 figures, new results for hyperon local polarization are addedJournal-ref: Phys. Rev. C 104, 041902 (2021)Subjects: Nuclear Theory (nucl-th); High Energy Physics - Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
In 2017, STAR Collaboration reported the measurements of hyperon global polarization in heavy ion collisions, suggesting the subatomic fireball fluid created in these collisions as the most vortical fluid. There remains the interesting question: at which beam energy the truly most vortical fluid will be located. In this work we perform a systematic study on the beam energy dependence of hyperon global polarization phenomenon, especially in the interesting $\hat{O}(1\sim 10)\ \rm GeV$ region. We find a non-monotonic trend, with the global polarization to first increase and then decrease when beam energy is lowered from $27~\rm GeV$ down to $3~\rm GeV$. The maximum polarization signal has been identified around $\sqrt{s_{NN}} = 7.7~\rm GeV$, where the heavy ion collisions presumably create the most vortical fluid. Detailed experimental measurements in the $\hat{O}(1\sim 10)\ \rm GeV$ beam energy region are expected to test the prediction very soon.
- [80] arXiv:2206.08327 (replaced) [pdf, html, other]
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Title: The BOSS bispectrum analysis at one loop from the Effective Field Theory of Large-Scale StructureComments: JCAP version, 23+18 pages, 6 figures, 5 tablesSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Theory (hep-th)
We analyze the BOSS power spectrum monopole and quadrupole, and the bispectrum monopole and quadrupole data, using the predictions from the Effective Field Theory of Large-Scale Structure (EFTofLSS). Specifically, we use the one loop prediction for the power spectrum and the bispectrum monopole, and the tree level for the bispectrum quadrupole. After validating our pipeline against numerical simulations as well as checking for several internal consistencies, we apply it to the observational data. We find that analyzing the bispectrum monopole to higher wavenumbers thanks to the one-loop prediction, as well as the addition of the tree-level quadrupole, significantly reduces the error bars with respect to our original analysis of the power spectrum at one loop and bispectrum monopole at tree level. After fixing the spectral tilt to Planck preferred value and using a Big Bang Nucleosynthesis prior, we measure $\sigma_8=0.794\pm 0.037$, $h = 0.692\pm 0.011$, and $\Omega_m = 0.311\pm 0.010$ to about $4.7\%$, $1.6\%$, and $3.2\%$, at $68\%$ CL, respectively. This represents an error bar reduction with respect to the power spectrum-only analysis of about $30\%$, $18\%$, and $13\%$ respectively. Remarkably, the results are compatible with the ones obtained with a power-spectrum-only analysis, showing the power of the EFTofLSS in simultaneously predicting several observables. We find no tension with Planck.
- [81] arXiv:2209.02741 (replaced) [pdf, html, other]
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Title: Probing ultralight scalar, vector and tensor dark matter with pulsar timing arraysComments: 6 pages, 3 figures, accepted by PLBSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Theory (hep-th)
Pulsar timing arrays (PTAs) are sensitive to oscillations in the gravitational potential along the line-of-sight due to ultralight particle pressure. We calculate the probing power of PTAs for ultralight bosons across all frequencies, from those larger than the inverse observation time to those smaller than the inverse distance to the pulsar. We show that since the signal amplitude grows comparably to the degradation in PTA sensitivity at frequencies smaller than inverse observation time, the discovery potential can be extended towards lower masses by over three decades, maintaining high precision. We demonstrate that, in the mass range $10^{-26} -10^{-23}$ eV, existing 15-year PTA data can robustly detect or rule out an ultralight component down to $O(1 - 10)\%$ of the total dark matter. Non-detection, together with other bounds in different mass ranges, will imply that ultralight scalar/axion can comprise at most $1-10\%$ of dark matter in the $10^{-30}\!-\!10^{-17}$ eV range. With 30 years of observation, current PTAs can extend the reach down to $0.1-1 \%$, while next-generation PTAs such as SKA can attain the $0.01-0.1\%$ precision. We generalize the analysis and derive predictions for ultralight spin-1 vector (i.e. dark photon) and spin-2 tensor dark components.
- [82] arXiv:2303.14156 (replaced) [pdf, html, other]
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Title: Non-Gaussianity in rapid-turn multi-field inflationComments: 33 pages, 9 figuresJournal-ref: JCAP 03 (2024) 014Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Theory (hep-th)
We show that theories of inflation with multiple, rapidly turning fields can generate large amounts of non-Gaussianity. We consider a general theory with two fields, an arbitrary field-space metric, and a potential that supports sustained, rapidly turning field trajectories. Our analysis accounts for non-zero field cross-correlation and does not fix the power spectra of curvature and isocurvature perturbations to be equal at horizon crossing. Using the $\delta N$ formalism, we derive a novel, analytical formula for bispectrum generated from multi-field mixing on super-horizon scales. Rapid-turn inflation can produce a bispectrum with several potentially large contributions that are not necessarily of the local shape. We exemplify the applicability of our formula with a fully explicit model and show that the new contributions indeed can generate a large amplitude of local non-Gaussianity, $f_{\rm NL}^{\rm loc}\sim {\cal O}(1)$. These results will be important when interpreting the outcomes of future observations.
- [83] arXiv:2305.03703 (replaced) [pdf, html, other]
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Title: Impact of the pre-equilibrium phase for the determination of nuclear geometry in high-energy isobar collisionsComments: v2: 26 pages, 12 figures. Extended discussion and new resultsSubjects: Nuclear Theory (nucl-th); High Energy Physics - Phenomenology (hep-ph)
Ultrarelativistic isobar collisions have been proposed as a useful tool to investigate nuclear structure. These systems are not created in equilibrium, rather undergo a prethermalization phase. In this phase, some of the initial structure information may be lost and additional effects introduced. The objective of this paper is to study this possibility in the extreme case of a "free-streaming" pre-equilibrium phase. We do this by computing estimators for ratios of various measured (or measurable) quantities (elliptic and triangular flows, mean transverse momentum and associated cumulants, correlators between elliptic or triangular flows and mean transverse momentum, symmetric cumulant and two-plane correlator) and study their sensitivity to the duration of the free-streaming phase. We find that the correlators between elliptic or triangular flows and mean transverse momentum, the so-called $\rho_2$ and $\rho_3$, are indeed sensitive to the duration of the free-streaming phase and that the normalized symmetric cumulant, $\epsilon NSC(2,3)$ might also depend on this duration.
- [84] arXiv:2308.03356 (replaced) [pdf, html, other]
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Title: Relativistic model-free prediction for neutrinoless double beta decay at leading orderComments: 8 pages, 4 figuresJournal-ref: Phys. Lett. B 855 (2024) 138782Subjects: Nuclear Theory (nucl-th); High Energy Physics - Lattice (hep-lat); High Energy Physics - Phenomenology (hep-ph)
Starting from a manifestly Lorentz-invariant chiral Lagrangian, we present a model-free prediction for the transition amplitude of the process $nn\rightarrow pp e^-e^-$ induced by light Majorana neutrinos, which is a key process of the neutrinoless double beta decay ($0\nu\beta\beta$) in heavy nuclei employed in large-scale searches. Contrary to the nonrelativistic case, we show that the transition amplitude can be renormalized at leading order without any uncertain contact operators. The predicted amplitude defines a stringent benchmark for the previous estimation with model-dependent inputs, and greatly reduces the uncertainty of $0\nu\beta\beta$ transition operator in the calculations of nuclear matrix elements. Generalizations of the present framework could also help to address the uncertainties in $0\nu\beta\beta$ decay induced by other mechanisms. In addition, the present work motivates a relativistic {\it ab initio} calculation of $0\nu\beta\beta$ decay in light and medium-mass nuclei.
- [85] arXiv:2310.11260 (replaced) [pdf, html, other]
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Title: Effective Theory Approach for Axion WormholesComments: 25 pages, 6 figures, v2: To appear in JHEP, added discussions on the cutoff scale and an appendix on the potential contributionSubjects: High Energy Physics - Theory (hep-th); High Energy Physics - Phenomenology (hep-ph)
We employ the effective field theory approach to analyze the characteristics of Euclidean wormholes within axion theories. Using this approach, we obtain non-perturbative instantons in various complex scalar models with and without a non-minimal coupling to gravity, as well as models featuring the $R^2$ term for a range of coupling values. This yields a series of analytical expressions for the axion wormhole action, shedding light on the model parameters and field dependencies of contributions in both the ultraviolet and infrared domains. Consequently, model-dependent local operators that disrupt axion shift symmetries are generated at lower energy levels. This, in turn, provides crucial insights into the gravitational influences on the axion quality problem.
- [86] arXiv:2311.07557 (replaced) [pdf, html, other]
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Title: Backreaction of axion-SU(2) dynamics during inflationComments: 25 pages, 13 figures, 2 tablesJournal-ref: JCAP04(2024)018Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Theory (hep-th)
We consider the effects of backreaction on axion-SU(2) dynamics during inflation. We use the linear evolution equations for the gauge field modes and compute their backreaction on the background quantities numerically using the Hartree approximation. We show that the spectator chromo-natural inflation attractor is unstable when back-reaction becomes important. Working within the constraints of the linear mode equations, we find a new dynamical attractor solution for the axion field and the vacuum expectation value of the gauge field, where the latter has an opposite sign with respect to the chromo-natural inflation solution. Our findings are of particular interest to the phenomenology of axion-SU(2) inflation, as they demonstrate the instability of the usual trajectory due to large backreaction effects. The viable parameter space of the model becomes significantly altered, provided future non-Abelian lattice simulations confirm the existence of the new dynamical attractor. In addition, the backreaction effects lead to characteristic oscillatory features in the primordial gravitational wave background that are potentially detectable with upcoming gravitational wave detectors.
- [87] arXiv:2311.12259 (replaced) [pdf, other]
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Title: Analytical models of supermassive black holes in galaxies surrounded by dark matter halosComments: revtex4-2, no figures. Version to appear in Phys. Lett. B 855 (2024) 138797Journal-ref: Phys. Lett. B 855 (2024) 138797Subjects: General Relativity and Quantum Cosmology (gr-qc); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Theory (hep-th)
In this Letter, we present five analytical models in closed forms, each representing a supermassive black hole (SMBH) located at the center of a galaxy surrounded by dark matter (DM) halo. The density profile of the halo vanishes inside twice the Schwarzschild radius of the hole and satisfies the weak, strong, and dominant energy conditions. The spacetime are asymptotically flat, and the difference among the models lies in the slopes of the density profiles in the spike and regions far from the center of the galaxy. Three of them represent cusp models, whereas the other two represent core models. With the well-known (generalized) Newman-Janis algorithm, rotating SMBHs with DM halos can be easily constructed from these models.
- [88] arXiv:2401.09908 (replaced) [pdf, html, other]
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Title: Algorithm for differential equations for Feynman integrals in general dimensionsComments: 47 pages. v2: Clarifications and comments added. Version to appear in Letters in Mathematical Physics. Results for differential operators are on the repository : this https URLSubjects: High Energy Physics - Theory (hep-th); High Energy Physics - Phenomenology (hep-ph); Mathematical Physics (math-ph)
We present an algorithm for determining the minimal order differential equations associated to a given Feynman integral in dimensional or analytic regularisation. The algorithm is an extension of the Griffiths-Dwork pole reduction adapted to the case of twisted differential forms. In dimensional regularisation, we demonstrate the applicability of this algorithm by explicitly providing the inhomogeneous differential equations for the multiloop two-point sunset integrals: up to 20 loops for the equal mass case, the generic mass case at two- and three-loop orders. Additionally, we derive the differential operators for various infrared-divergent two-loop graphs. In the analytic regularisation case, we apply our algorithm for deriving a system of partial differential equations for regulated Witten diagrams, which arise in the evaluation of cosmological correlators of conformally coupled $\phi^4$ theory in four-dimensional de Sitter space.
- [89] arXiv:2402.15628 (replaced) [pdf, html, other]
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Title: Toward extracting the scattering phase shift from integrated correlation functions II: a relativistic lattice field theory modelComments: match to PRD accepted versionSubjects: High Energy Physics - Lattice (hep-lat); High Energy Physics - Phenomenology (hep-ph); Nuclear Theory (nucl-th)
In present work, a relativistic relation that connects the difference of interacting and non-interacting integrated two-particle correlation functions in finite volume to infinite volume scattering phase shift through an integral is derived. We show that the difference of integrated finite volume correlation functions converge rapidly to its infinite volume limit as the size of periodic box is increased. The fast convergence of our proposed formalism is illustrated by analytic solutions of a contact interaction model, the perturbation theory calculation, and also Monte Carlo simulation of a complex $\phi^4$ lattice field theory model.
- [90] arXiv:2403.04316 (replaced) [pdf, html, other]
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Title: Testing scale-invariant inflation against cosmological dataComments: 39 pages, 4 figures, 1 table. v2: additional references added, clarified some aspects of the analysis with regards to reheating and convergence of the results, clarified differences with respect to earlier results. Version accepted for publication in JCAPSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Theory (hep-th)
There is solid theoretical and observational motivation behind the idea of scale-invariance as a fundamental symmetry of Nature. We consider a recently proposed classically scale-invariant inflationary model, quadratic in curvature and featuring a scalar field non-minimally coupled to gravity. We go beyond earlier analytical studies, which showed that the model predicts inflationary observables in qualitative agreement with data, by solving the full two-field dynamics of the system -- this allows us to corroborate previous analytical findings and set robust constraints on the model's parameters using the latest Cosmic Microwave Background (CMB) data from Planck and BICEP/Keck. We demonstrate that scale-invariance constrains the two-field trajectory such that the effective dynamics are that of a single field, resulting in vanishing entropy perturbations and protecting the model from destabilization effects. We derive tight upper limits on the non-minimal coupling strength, excluding conformal coupling at high significance. By explicitly sampling over them, we demonstrate an overall insensitivity to initial conditions. We argue that the model \textit{predicts} a minimal level of primordial tensor modes set by $r \gtrsim 0.003$, well within the reach of next-generation CMB experiments. These will therefore provide a litmus test of scale-invariant inflation, and we comment on the possibility of distinguishing the model from Starobinsky and $\alpha$-attractor inflation. Overall, we argue that scale-invariant inflation is in excellent health, and possesses features which make it an interesting benchmark for tests of inflation from future CMB data.
- [91] arXiv:2403.15305 (replaced) [pdf, html, other]
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Title: X-ray emission spectrum for axion-photon conversion in magnetospheres of strongly magnetized neutron starsComments: Accepted in European Physical Journal C (15 pages, 17 figures)Subjects: High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics - Phenomenology (hep-ph)
Detecting axionic dark matter (DM) could be possible in an X-ray spectrum from strongly magnetized neutron stars (NSs). We examine the possibility of axion-photon conversion in the magnetospheres of strongly magnetized NSs. In the current work, we investigate how the modified Tolman Oppenheimer Volkoff (TOV) system of equations (in the presence of a magnetic field) affects the energy spectrum of axions and axions-converted-photon flux. We have considered the distance-dependent magnetic field in the modified TOV system of equations. We employ three different equations of states (EoSs), namely APR, FPS, and SLY, to solve these equations. We obtain the axions emission rate by including the Cooper-pair-breaking formation process and Bremsstrahlung process in the core of NSs using the NSCool code. We primarily focus on Magnificient seven (M7) star RXJ 1856.5-3754. We further investigate the impact of the magnetic field on the actual observables, such as axion energy spectrum and axion-converted-photon flux at an axion mass in meV range by assuming mass $M_{NS} \sim 1.4M_{\odot}$. We compare our calculated axion-converted-photon flux from all available archival data sets from PN+MOS+Chandra. We also study the variation of the energy spectrum at a fixed energy with varying central magnetic fields. Our predicted axion-converted-photon flux values as a function of axion energy closely follow the experimentally archival data, which allows us to put bounds on the axion mass for the three EoS.
- [92] arXiv:2404.03503 (replaced) [pdf, html, other]
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Title: Wilson Loops and Random MatricesComments: 23 pages, 12 figuresSubjects: High Energy Physics - Theory (hep-th); High Energy Physics - Lattice (hep-lat); High Energy Physics - Phenomenology (hep-ph)
Linear confinement with Casimir scaling of the string tension in confining gauge theories is a consequence of a certain property of the Polyakov loop related to random matrices. This mechanism does not depend on the details of the theories (neither the gauge group nor dimensions) and explains approximate Casimir scaling below string-breaking length. In this paper, we study 3d SU(2) pure Yang-Mills theory numerically and find the same random-matrix behavior for rectangular Wilson loops. We conjecture that this is a universal feature of strongly coupled confining gauge theories.