Fri·May 29, 2026Friday·May 29, 2026

1. 01*

   Twilight of the WIMP: Comprehensive Phenomenology of Electroweak Triplet Dark Matter

   Gaurav🇮🇳 · Niharika Shrivastava🇮🇳 · Rahul Srivastava🇮🇳 · Sushant Yadav🇮🇳

   We present a comprehensive study of dark matter phenomenology in standard model extensions featuring an electroweak triplet scalar or fermion with hypercharge $Y=0$ or $Y=2$. These minimal triplet extensions provide well-motivated dark matter candidates stabilised by the $Z_2$ discrete symmetry. We perform a detailed analysis of the parameter space consistent with current cosmological and experimental constraints, including the relic abundance, direct detection limits, and indirect detection bounds. We find that the scalar triplet with $Y=0$ is ruled out by a combination of relic density, direct detection and indirect detection constraints. On the other hand, the scalar and fermionic triplets with $Y=2$ are both excluded by current direct detection experiments due to their large spin-independent scattering cross-sections. The viable parameter space of the remaining $Y=0$ fermion triplet dark matter lies within the projected sensitivity of near-future experiments, particularly those targeting indirect detection signatures. Collider prospects for these triplet extensions are also discussed in the Appendix.

   hep-phgr-qchep-ex0 citations
2. 02*

   Visible inelasticity as a probe of tau flavor content of astrophysical neutrinos

   Alex Y. Wen🇺🇸 · Carlos A. Argüelles🇺🇸 · Sergio Palomares-Ruiz🇪🇸

   Astrophysical neutrinos provide a unique probe of neutrino flavor changes over cosmological baselines. While the tau component of the neutrino flux is expected to arise almost entirely from mixing, current measurements rely primarily on rare double-cascade signatures. We investigate a complementary method to measure the tau fraction using the visible inelasticity of starting track events in neutrino telescopes. Muonic decays of tau leptons produce tracks with systematically larger visible inelasticity than those from muon neutrino interactions, potentially enabling statistical separation of the two flavors. Using realistic IceCube exposures and detector performance, we show that this observable already yields competitive sensitivity to the tau-to-muon flux ratio, $R_{\tau \mu }$, achievable with existing data. This approach may further enable flavor measurements of individual sources and the selection of tau-enhanced source catalogs. Starting-track inelasticity thus provides a powerful and immediately accessible probe of astrophysical neutrino flavor and of potential physics beyond standard neutrino mixing.

   hep-phastro-ph.HEhep-ex1 citation
3. 03*

   Dynamical Tsallis WIMP Freeze-Out and Residual Memory Channels in the Radiation Sector

   Matias P. Gonzalez🇨🇱

   In this work we generalize the thermal decoupling, or freeze-out, of weakly interacting massive particle dark matter within the Tsallis nonextensive formalism. The generalization is implemented through $q$-deformed distribution functions obtained from the maximum entropy principle with Curado-Tsallis constraints. The Tsallis parameter $q$, which measures deviations from extensivity with respect to the limit $q=1$, is promoted to a dynamical quantity depending on the dimensionless variable $x=m_{\chi }/T$, where $m_{\chi }$ is the dark matter mass. This dynamical evolution is characterized by a relaxation toward extensivity, while requiring that the nonextensive deformation is not completely erased before freeze-out. We solve the Boltzmann equation assuming a sectorial deformation, where only the dark matter equilibrium abundance is generalized and the radiation background remains extensive. The relic abundance is computed for different dark matter masses and initial values of the Tsallis parameter. From this evolution, we extract the residual value $q_{\chi }^{\mathrm{fo}}$ at freeze-out, which is then used as the initial input for a phenomenological memory channel. This channel propagates the residual nonextensivity into the radiation sector, specifically into the electron-positron plasma and neutrinos, while photons are kept extensive in order to avoid direct tensions with CMB physics. The resulting deformation modifies the neutrino energy density and the photon reheating contribution, producing a correction to $N_{\mathrm{eff}}$. We compare the predicted values with the compressed CMB+BAO constraint on $N_{\mathrm{eff}}$ and find that the residual-memory scenario can remain phenomenologically compatible with current bounds.

   hep-phastro-ph.COcond-mat.stat-mech0 citations
4. 04*

   Hiding in the Shadow of the Upsilon: Ditaus from a Light Pseudoscalar

   Matthew R Buckley🇺🇸 · David Shih🇺🇸 · Isaac R Wang🇺🇸

   The CMS collaboration has reported a measurement of ${\rm Y}$ decays to ditaus using $61.9{\mathrm{fb}}^{-1}$ of scouting data. If interpreted as the decay of ${\rm Y}(1S,2S,3S)$, the measured ditau rate is more than ten times that seen in the dimuon final states at the $\sim 3\sigma$ level, and is likewise inconsistent with the branching ratios measured at $B$-factories. If confirmed with more data and at higher significance, such a violation of lepton flavor universality would necessitate new physics. In this Letter, we present a simple model with a light pseudoscalar coincidentally near the ${\rm Y}(1S)$ mass, which mixes with two Higgs doublets in the alignment limit. Such a particle naturally decays primarily to taus and evades all existing experimental constraints, while implying a number of predictions that can be tested in the near future.

   hep-phhep-ex2 citations
5. 05*

   Alignment and Enhanced Multi-Higgs Production

   Subhojit Roy🇺🇸 · Carlos E. M. Wagner🇺🇸

   Contrary to conventional expectations, we identify a class of extended scalar-sector scenarios in which final states with two, three, or four Higgs bosons constitute the leading discovery channels for new physics at the LHC. In these scenarios, higher-dimensional interactions, together with suppressed Higgs-scalar mixing near the alignment limit, reorganize the decay patterns of new scalar states, suppressing conventional modes while enhancing multi-Higgs final states. We illustrate the emergence of dominant triple- and quadruple-Higgs signatures in two representative realizations: a single-scalar extension of the Standard Model, where higher-dimensional operators suppress conventional two-body decays while preserving couplings to higher-multiplicity Higgs final states; and a two-singlet scenario, where similar signatures arise through cascade decays with a simpler operator structure. In both cases, the new scalar states can be produced via gluon fusion, yielding potentially observable rates for multi-Higgs production at the LHC. Although both realizations lead to identical final states, they exhibit distinct kinematic features reflecting their underlying topologies, providing a direct handle on the dynamics.

   hep-phhep-ex2 citations
6. 06*

   High-Quality Axion Dark Matter without Isocurvature Problem

   Masahiro Kawasaki🇯🇵 · Jie Sheng🇯🇵 · Tsutomu T. Yanagida🇯🇵

   Axion dark matter in high-scale inflation is subject to the isocurvature constraint, since quantum fluctuations of the axion field during inflation may exceed the current CMB bound. One conventional way to suppress these fluctuations is to assume that the Peccei-Quinn field has a large expectation value during inflation. However, this mechanism becomes ineffective when the axion domain wall number is large. In this work, we point out that a high-quality axion protected by a discrete gauge symmetry can naturally evade this problem. A Peccei-Quinn-violating but gauge-invariant operator induces a large effective axion mass during inflation, thereby suppressing the axion fluctuation. The same setup can address both the axion quality problem and the isocurvature problem, while leading to a prediction for the axion parameter space to be verified in future experiments.

   hep-phgr-qc2 citations
7. 07*

   Charmonium production at SPS and FAIR energies

   Taesoo Song🇩🇪 · Jiaxing Zhao🇩🇪 · Joerg Aichelin🇫🇷 · Elena Bratkovskaya🇩🇪

   In this study we apply the Remler formalism to charmonium production at SPS and GSI/FAIR energies in order to investigate the effects of baryon-rich matter on charmonium production and dissociation in heavy-ion collisions within the Parton-Hadron-String Dynamics (PHSD). As a first step the Remler formalism is tested in p+p collisions and then applied to p+A collisions in order to extract the nuclear absorption cross section of charmonium, which is then utilized in heavy-ion collisions. We find that the Remler formalism successfully describes charmonium production in heavy-ion collisions at SPS energies when an in-medium heavy quark potential is implemented, in which $J/\psi$ dissociates near $T_c$. Finally the same formalism is applied to the low CERN/SPS energy and GSI/FAIR energies, where we estimate charmonium production.

   hep-ph2 citations
8. 08*

   Polyakov-loop potential of accelerated gluonic matter and thermodynamic subtleties

   Hao-Lei Chen🇨🇳 · Kenji Fukushima🇯🇵 · Yu-Han Gao🇨🇳 · Xu-Guang Huang🇨🇳 · Yusuke Shimada🇯🇵 · Zhi-Bin Zhu🇨🇳

   We study the one-loop Polyakov-loop effective potential in pure gluonic matter under constant acceleration. We perform the computation in both the Euclidean Rindler spacetime and the optical spacetime, which are related via a conformal transformation. The results from the two formulations correspond to physically different observables, and we clarify their connection to specific components of the energy-momentum tensor. This identification resolves a discrepancy previously noted for fields on conical backgrounds. For the Polyakov-loop expectation value, we should minimize the effective potential computed in the optical metric formulation, which concludes that real acceleration strengthens deconfining properties. We also discuss analytic continuation from real to imaginary acceleration and find a perturbatively confined phase. We point out some suggestive similarities and differences between systems under imaginary acceleration and imaginary rotation.

   hep-phPRD(2026)·0 citations
9. 09*

   Quantum field theory of massive chiral fields

   Massimo Blasone🇮🇹 · Petr Jizba🇨🇿 · Luca Smaldone🇮🇹

   We present a quantum-field-theoretic treatment of massive chiral fields in which particles possess well-defined chirality and helicity. This framework reproduces the chiral oscillation formula previously obtained in first-quantized approaches and provides a consistent description of weak-interaction processes. We further derive corresponding chiral-energy uncertainty relations.

   hep-phhep-th0 citations
10. 10*

    Thermodynamics in symmetry-improved Cornwall-Jackiw-Tomboulis formalism: application to the low-energy effective theory of QCD

    Yuepeng Guan🇨🇳 · Mamiya Kawaguchi🇺🇸 · Shinya Matsuzaki🇨🇳 · Akio Tomiya🇯🇵

    We study the thermodynamics of the symmetry-improved Cornwall-Jackiw-Tomboulis (SICJT) formalism and apply it to a low-energy effective theory of QCD. In the symmetry-improved formulation, Ward-Takahashi identities are restored by auxiliary sources whose values are fixed self-consistently by the equilibrium state. While this construction improves the symmetry properties of the loop-wise truncated two-particle-irreducible (2PI) theory, it also makes the thermodynamic interpretation of the pressure nontrivial. We formulate several pressure prescriptions, including the conventional vacuum-subtracted pressure, a source-matched subtraction, and a pulled-back pressure in which the explicit source-induced energy shift is removed. Using the three-flavor linear sigma model with quarks, we analyze the equation of state, isentropic trajectories, adiabatic sound velocity, and trace anomaly across the chiral transition. We find that the global thermodynamic structure is stable under the different prescriptions, while quantitative differences are concentrated near the crossover and first-order transition region. These results establish a practical framework for constructing thermodynamically consistent observables in symmetry-improved 2PI approaches.

    hep-phhep-thPRD(2026)·0 citations
11. 11*

    HyperPrecision: A Mathematica package for High-Precision Numerical Evaluation of Multivariate Hypergeometric Functions

    Sumit Banik🇺🇸 · Souvik Bera🇰🇷

    In this paper, we present HyperPrecision, a Mathematica package for high-precision numerical evaluation of general Horn-type multivariate hypergeometric functions and their Laurent expansions in a small parameter $ϵ$. Such functions appear widely in physics and mathematics, with applications ranging from quantum field theory and string theory to number theory and statistics. Their high-precision numerical evaluation, however, remains challenging, since their defining series converge only in restricted domains and analytic continuation beyond these domains is, in general, non-trivial. HyperPrecision addresses this problem by automatically constructing the Pfaffian system of partial differential equations for a given hypergeometric function and restricting it to a one-dimensional contour in the space of variables connecting the starting to the target point. The resulting ordinary differential equation is then solved by the Frobenius method, with boundary conditions fixed analytically by the defining series. We illustrate the use of the package by evaluating commonly occurring multivariate hypergeometric functions, including the Appell $F_1$, $F_2$, $F_3$, and $F_4$ functions, the Horn $G$- and $H$-series, and the Lauricella $F_A$, $F_B$, $F_C$, and $F_D$ functions, as well as by considering applications to angular integrals, Feynman integrals, and cosmological and holographic correlators.

    hep-phhep-thmath-phmath.MPComput.Phys.Commun.(2026)·1 citation
12. 12*

    Leptonic CP Phase Determination from Fisher Information in NO$\nu$A and T2K

    Neetu Raj Singh Chundawat🇮🇳 · Luis A. Delgadillo🇨🇳 · Yu-Feng Li🇨🇳

    The precise determination of the leptonic CP phase ${\delta }_{\mathrm{CP}}$ remains one of the central objectives of current and future long-baseline (LBL) neutrino oscillation experiments. Quantum estimation theory provides a natural framework to quantify the ultimate precision limits for estimating physical parameters encoded in quantum states. In this work, we employ the quantum Fisher information to investigate how much information about ${\delta }_{\mathrm{CP}}$ is intrinsically encoded in neutrino states and how efficiently it is extracted in present LBL experiments such as T2K and NO$\nu$A. We first analyze the intrinsic quantum sensitivity of neutrino and antineutrino states and demonstrate how matter effects generate a neutrino mass-ordering dependent information structure. To compare the intrinsic information content of the quantum state with the information experimentally accessible through flavor measurements, we compute the event-level Fisher information from reconstructed event spectra using Poisson statistics. We find that both experiments extract only a small fraction of the total information available in the underlying quantum state. This extraction efficiency becomes particularly suppressed near maximally CP-violating regions, where the reconstructed event spectra exhibit reduced sensitivity to small variations in ${\delta }_{\mathrm{CP}}$. Our analysis provides a complementary information-theoretic perspective on precise estimation of oscillation parameters in LBL neutrino experiments.

    hep-phquant-ph5 citations
13. 13*

    Quark-Lepton Color-Flavor Unification

    Antonio Delgado🇺🇸 · Seth Koren🇺🇸

    We present an $SU(12)\times SU(2{)}_L\times U(1{)}_R$ model unifying $SU(9)$ quark color-flavor with $SU(3)$ lepton flavor as a flavorful alternative to conventional theories of unification. We begin in the ultraviolet with a single yukawa shared by the unified up-type quarks and neutrinos, and no further new fermions. We show that gauged quark color-flavor and lepton flavor instantons dynamically generate the bottom and tau yukawas, which implements a massless quark solution to the strong CP problem and sets up a flavored type-I seesaw mechanism. Only two new scalar irreps are needed for the symmetry-breaking steps, which include quark color-flavor deconstruction and then infrared reunification, and the Standard Model gauge group in this theory emerges as \[G_{\rm SM} = \frac{SU(3)_C \times SU(2)_L \times U(1)_Y \times \mathbb{Z}^X_{18}}{\mathbb{Z}_{3} \times \Gamma \times \mathbb{Z}_3},\] where $\Gamma \in \{1,{\mathbb{Z}}_2\}$ is the electroweak global structure and there is a discrete gauge symmetry $X=B-3(L_i+L_j-L_k)$ which brings additional ${\mathbb{Z}}_3$ global structure to the SM. This gauge symmetry acts as a flavorful upgrade of the ${\mathbb{Z}}_{18}^{B+L}$ anomaly-free global symmetry of the SM and stabilizes the proton absolutely. Non-invertible chiral symmetry-breaking is crucial to our model, and we discuss the rich spectrum of emergent generalized symmetries and topological defects appearing at various stages. In the infrared, the novel shared quotient between continuous and discrete groups links the one-form and two-form global symmetries of the Standard Model.

    hep-phhep-th1 citation
14. 14*

    A Bandpass Axion Or: How I Learned To Stop Worrying About Stars And Love The Lab

    Dawid Brzeminski🇺🇸 · Anson Hook🇺🇸

    Axion-like particles coupled to photons are one of the most compelling new physics scenarios. We demonstrate that an axion-photon coupling resulting from a non-anomalous PQ symmetry under which light fermions are charged acts as a bandpass filter: both high- and low-energy probes experience a parametrically suppressed coupling while intermediate-energy probes remain unaffected. An immediate result of this bandpass is that lab-based constraints can naturally be the dominant constraint for almost all values of the axion mass. High-energy constraints coming from stellar dynamics as well as low-energy constraints coming from photon-axion conversion in galactic/stellar magnetic fields are simultaneously suppressed, while lab-based experiments, such as light-shining-through-a-wall experiments, done at intermediate energies are unsuppressed.

    hep-ph0 citations
15. 15*

    New quantum information perspectives in the axion--photon and neutrino systems

    Aaditya Datar🇮🇳 · Arun M. Thalapillil🇮🇳 · Palak Thareja🇮🇳

    In this work, we broach a quantum information-theoretic treatment of axion--photon mixing. Motivated by an emerging class of quantum-enhanced axion searches, we analyse the two-level single-excitation sector of axion--photon oscillations, demonstrating how the coupled dynamics naturally generate bipartite axion--photon mode entanglement. We study in detail the ensuing aspects of entanglement entropy, concurrence, negativity, quantum mutual information and discord, and capacity of entanglement, and the corresponding neutrino analogues wherever novel and previously unaddressed. In particular, we highlight the characteristic features that connect maximal axion--photon entanglement to resonant or strong-mixing conversion, and the distinct thresholds for the extremal values attained by the quantum information measures. We study aspects of the Mandelstam--Tamm and Margolus--Levitin quantum speed limits for both the axion--photon and neutrino systems. While orthogonalisation occurs only at axion--photon resonance, or at maximal neutrino mixing, where the two bounds coincide, away from these limits, the Margolus--Levitin bound is saturated at maximal conversion, while the Mandelstam--Tamm bound is generally weaker. We also study an entanglement quantum speed limit for axion--photon conversion, that separates into detuning-dominated and magnetic-mixing-dominated regimes, and find that it is saturated for a period and then the bound becomes weak. The results in this work identify the quantum resources and limiting timescales intrinsic to axion--photon conversion, and connect axion phenomenology, neutrino oscillations and quantum information theory.

    hep-phhep-exhep-thquant-ph0 citations
16. 16*

    Millicharged Particle Constraints from Asymptotic Giant Branch Stars

    Damiano F.G. Fiorillo🇮🇹 · Giuseppe Lucente🇺🇸 · Jeremy Sakstein🇺🇸 · Edoardo Vitagliano🇮🇹

    We investigate the effect of millicharged particles (MCPs) with electric charge $qe\ll e$ and mass $m_{\chi }$ on the late-stage evolution phases of low-mass stars in globular clusters. We predict the $R_2$ parameter -- the ratio of the number of stars in the asymptotic giant branch (AGB) phase to the number of stars in the horizontal branch (HB) phase -- and compare it against globular cluster data. While the production of MCPs shortens both the HB and AGB lifetimes, a larger reduction in the AGB phase arises from the higher temperatures in the helium-burning shell. We find the strongest bounds in the range $10\mathrm{keV}\lesssim m_{\chi }\lesssim 100\mathrm{keV}$, reaching charges as small as $q\simeq 5\times 10^{-13}$ and surpassing existing constraints by up to two orders of magnitude.

    hep-phastro-ph.SR1 citation
17. 17*

    Nonlinear Dynamics of Rapidly Driven Systems

    Afshin Besharat🇨🇦 · Alexander A. Penin🇨🇦

    We consider systems characterized by the presence of a rapidly oscillating force. A general method is presented for the construction of the effective action governing the large-scale nonlinear dynamics of such systems order by order in inverse powers of the oscillation frequency $\omega$. The explicit expression for the effective Lagrangian is derived up to $\mathcal{O}(1/{\omega }^6)$ next-to-next-to-leading approximation. The general structure of the high-frequency expansion reveals a broad class of nonlinear systems whose transition curves are identical to those of the linear Mathieu equation, which enables a fully nonperturbative stability analysis in the case of strong driving and nonlinearity. The method is generalized to velocity-dependent forces and configuration space with curvature, characteristic to systems with constraints. Several applications are discussed in detail, including the dynamical magnetic trapping of electric charges.

    ↳ nlin.CDcond-mat.mes-hallhep-phphysics.atom-ph+10 citations
18. 18*

    Bayesian constraints on the transport coefficients $\eta /s$ and $\zeta /s$ from spin polarization in relativisitic heavy-ion collisions

    Sushant K. Singh🇮🇹 · Eduardo Grossi🇮🇹 · Francesco Becattini🇮🇹

    Bayesian analyses in the context of relativistic heavy-ion collisions have so far relied almost exclusively on bulk hadronic observables constructed from momentum degrees of freedom to constrain the transport properties of the quark-gluon plasma. In this work, we perform the Bayesian inference after incorporating the longitudinal spin polarization of $\Lambda$ hyperons alongside conventional bulk measurements in Pb+Pb collisions at $\sqrt{s_{NN}}=5.02$ TeV to constrain the shear and bulk viscosity to entropy density ratios, $\eta /s$ and $\zeta /s$. We demonstrate that the inclusion of spin polarization, which provides complementary sensitivity to the space-time structure and vorticity of the medium, shifts the posterior distribution of $\zeta /s$ toward larger values, although current uncertainties do not allow a statistically significant separation at the 68% credibility level. Nevertheless, the results establish spin polarization as a valuable probe in quantitative studies of QGP transport properties and indicate that it should be incorporated in comprehensive and systematically constrained Bayesian extractions of the medium's dynamical parameters.

    ↳ nucl-thhep-ph0 citations
19. 19*

    Magic Relations and Critical Varieties of Feynman Integrals

    Giulio Crisanti🇬🇧 · Hjalte Frellesvig🇨🇳 · Andrzej Pokraka🇳🇱 · Sid Smith🇮🇹

    Magic relations are a class of integration-by-parts identities where all integrals in the generating sector drop out. Since their presence causes several otherwise successful methods in the Feynman-integral computational pipeline to break down, they are important to detect and understand. In this paper, we take a first step toward a systematic characterization of such identities. Specifically, we observe and argue that the occurrence of magic relations always coincides with the presence of higher-dimensional critical varieties in the generating sector. This provides a practical computational test to check if a family of Feynman integrals can contain magic relations and to find them, which we implement in the ancillary Mathematica file Magic-Test.m. Additionally, we discuss how to count the number of master integrals in the presence of higher-dimensional critical varieties, classify the behavior of magic relations under symmetries, and we discuss their interplay with cuts.

    ↳ hep-thhep-phmath-phmath.MP3 citations
20. 20*

    Electromagnetic pion mass splitting using a Pauli-Villars-regulated photon propagator

    Alessandro De Santis🇩🇪 · Dominik Erb🇩🇪 · Harvey B. Meyer🇩🇪

    We present a lattice QCD calculation of the charged-neutral pion mass splitting $M_{{\pi }^{+}}-M_{{\pi }^0}$ at $\mathcal{O}({\alpha }_{\mathrm{em}})$ using a recently proposed framework based on a Pauli-Villars (PV) regulated photon propagator defined in the continuum and infinite-volume limit, with $\Lambda$ acting as an additional UV cutoff scale. The use of this propagator avoids power-law finite-volume effects, allowing for a straightforward treatment of the infinite-volume limit. We perform the calculation using CLS ensembles, studying finite-volume effects, the continuum limit and the extrapolation to the physical point for several values of the scale $\Lambda$. By means of the Cottingham formula, we further decompose the result into elastic and inelastic contributions at fixed $\Lambda$. Our final result, after removing the cutoff scale $\Lambda$, is $M_{{\pi }^{+}}-M_{{\pi }^0}=4.56(22)$ MeV, in good agreement with the experimental measurement. This calculation serves as a validation of the formalism in a well-controlled setting and offers useful insights into the application of electromagnetic corrections to other observables.

    ↳ hep-lathep-ph0 citations
21. 21*

    Black Hole Photon Rings Saturate the Quantum Chaos Bound

    D. Giataganas🇹🇼 · G.F. Giudice🇦🇪 · A. Kehagias🇬🇷 · F. Quevedo🇬🇧 · A. Riotto🇨🇭

    We study the quantum chaos bound in the photon ring region surrounding black holes. By evaluating the Lyapunov exponent associated with unstable null geodesics in a broad class of generalized Kerr geometries, as well as the temperature induced by a string probe, we show that the quantum chaos bound is exactly saturated on equatorial circular orbits of the photon ring. We confirm our result by deriving the same exponent from out-of-time-order correlators in the near ring region. As a byproduct, we show that the photon ring saturation of the quantum chaos bound implies the saturation of the Bekenstein bound on the rate of information emission from the ringdown phase through the quasi-normal modes in the eikonal limit. Our results extend the known correspondence between black hole thermodynamics and chaotic dynamics, highlighting the role of the photon ring as a probe of the fundamental limits on thermalization and information scrambling in black holes.

    ↳ hep-thastro-ph.COgr-qchep-ph6 citations
22. 22*

    Higher Mellin Moments of the Unpolarized PDF of the Pion and the Kaon from Lattice QCD

    Constantia Alexandrou (Univ. of Cyprus and The Cyprus Inst.)🇨🇾 · Simone Bacchio (The Cyprus Inst.)🇨🇾 · Priyajit Jana (Univ. of Cyprus and The Cyprus Inst.)🇨🇾 · Marcus Petschlies (Univ. of Bonn)🇩🇪 · Luis Alberto Rodriguez Chacon (The Cyprus Inst. and Univ. of Ferrara)🇨🇾 · Gregoris Spanoudes (Univ. of Cyprus)🇨🇾 · Fernanda Steffens (Univ. of Bonn)🇩🇪 · Carsten Urbach (Univ. of Bonn)🇩🇪 · Urs Wenger (Univ. of Bern)🇨🇭

    We present results on the Mellin moments of the unpolarized parton distribution function (PDF) of the pion and kaon up to the fourth order. The computation is done using one $N_f=2+1+1$ gauge ensemble of twisted mass fermions with quark masses tuned to approximately their physical values. We reconstruct the valence pion and kaon PDFs using the connected contributions to the three Mellin moments. We compare our results on the Mellin moments and the reconstructed PDFs with other lattice QCD and phenomenological determinations.

    ↳ hep-lathep-exhep-phnucl-th3 citations
23. 23*

    Mellin Moments of the Unpolarized Gluon PDF in the Proton from Nonlocal Operators in Lattice QCD

    Joseph Delmar🇺🇸 · Krzysztof Cichy🇵🇱 · Martha Constantinou🇺🇸 · Yong Zhao🇺🇸

    We present a lattice QCD determination of the Mellin moments of the unpolarized gluon parton distribution function in the proton. The analysis is based on matrix elements of nonlocal gluon operators coupled to momentum-boosted proton states. The calculation relies on an $N_f=2+1+1$ ensemble of maximally twisted mass fermions with clover improvement and the Iwasaki-improved gauge action, at a pion mass of approximately 260 MeV. Working within the short-distance operator product expansion (OPE) of the reduced gluon Ioffe-time distribution, we extract ratios of higher-order gluon moments, $⟨x^n⟩$ with $n>1$, to the gluon momentum fraction, $⟨x⟩$. We investigate systematic effects associated with the truncation of the order of moment in the OPE, the choice of minimum and maximum Wilson-line separations entering the analysis, and the treatment of mixing with the quark-singlet under perturbative matching. The stability of the extracted moments is further studied under scale evolution using DGLAP equations, allowing us to assess uncertainties related to perturbative truncation by varying the scale. Our work provides a determination of the ratio $⟨x^3{⟩}_g/⟨x{⟩}_g$ at a scale of 2 GeV, with uncertainties that account for both statistical and the dominant theoretical systematic uncertainties.

    ↳ hep-lathep-phhep-thnucl-th1 citation
24. 24*

    The relative interfacial thermal contraction as a possible origin of the low-energy excess in cryogenic calorimeters

    Vanessa Zema🇩🇪 · Pasquale Pavone🇩🇪

    Low threshold cryogenic calorimeters are a key technology for the advancement of rare-event searches. However, since a few years their sensitivity reach is challenged by the presence of a rising spectrum at low energies named low-energy excess (LEE), ascribed to an unknown background. In this work, we describe the LEE as absorber events induced by the relative thermal-contraction coefficient mismatch between the absorber and the SiO${}_2$ amorphous layer underneath the transition-edge sensors (TESs), present for example in the case of CRESST detectors. The relative contraction in processes with temperature changes, such as during sensor fabrication and cooldown from room temperature to the temperature of operation, can induce surface dislocation nucleation. Other interfaced materials with thermal-expansion mismatch can also generate dislocations during temperature-variation processes. We formulate a simple elastic model to bridge this solid-state effect and the LEE observations. Double-TES modules have been designed to provide surface background rejection. We highlight that the presence of the LEE in the coincident event band of double-TES modules does not exclude the explanation given in this work. Exemplary, we discuss the role of the thermal boundary resistance between absorber and sensor as explanation for the presence of the LEE in the coincident-event band. We propose detector designs to test these hypotheses and mitigate the LEE.

    ↳ physics.ins-dethep-ph0 citations
25. 25*

    Late-time Quantum Vacuum Decay and its Cosmological Implications

    Yang Bai🇺🇸 · Sida Lu🇨🇳 · Nicholas Orlofsky🇵🇱

    The existence of a landscape of metastable vacua raises the possibility that our Universe may have undergone quantum vacuum decay at late times. This work explores how such a transition can be tested with cosmological observables, focusing on precision distance measurements and cosmic microwave background (CMB) anisotropies. A set of phenomenological models is constructed in which late-time quantum tunneling changes the vacuum energy and may convert a subcomponent of dark matter into dark radiation, possibly accompanied by domain-wall production. The resulting expansion histories are compared with DESI DR2 baryon acoustic oscillation data; supernova distance measurements from DES-Dovekie, Pantheon+, and Union3; and a compressed CMB likelihood. For quantum-tunneling models, current cosmological distance measurements still allow a 50% decrease in the total vacuum energy for a transition redshift $z_t<1$. The model with dark-matter conversion and domain-wall production provides a good fit to resolve the tension between cosmological observables and the $\Lambda$CDM model, with a preferred transition around $z_t\sim 7$ and about 10% of dark matter participating in the transition. Additionally, CMB anisotropy constraints from bubble nucleation and the associated domain-wall network are derived and shown to strongly restrict slow or sparse late transitions. Applied to the minimal quantum-tunneling model, these constraints allow an $\mathcal{O}(10\%)$ decrease in the total vacuum energy for a transition redshift $z_t$ of order unity. For nonminimal models, dark-matter-density-dependent tunneling can proceed rapidly enough to evade such bounds. These results demonstrate that late-time quantum vacuum decay is a testable cosmological phenomenon and provide a concrete observational handle on metastable-vacuum physics motivated by landscape scenarios.

    ↳ astro-ph.COhep-phhep-th2 citations
26. 26*

    Axions Create Singularities on Extremal Horizons

    Gary T. Horowitz🇺🇸 · Maciej Kolanowski🇺🇸 · Grant N. Remmen🇺🇸 · Jorge E. Santos🇬🇧

    We show that axions cause extremal black holes to have singular horizons. This is true for almost all values of the axion mass and coupling provided the black hole is rotating and has some arbitrarily small nonzero charge. When the axion mass becomes large, these singularities are related to the recently discovered singularities induced by higher-derivative corrections to the Einstein-Maxwell equations. Away from extremality, this effect produces anomalously large tidal forces in the vicinity of near-extremal horizons, causing breakdown of the effective theory.

    ↳ hep-thastro-ph.HEgr-qchep-ph2 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.