Thu·Feb 27, 2025Thursday·February 27, 2025

1. 01*

   Next-to-next-to-leading order threshold soft function for $tW$ production

   Jia-Le Ding🇨🇳 · Hai Tao Li🇨🇳 · Jian Wang🇨🇳

   We compute the two-loop soft function for the associated production of a top quark and a $W$ boson near the threshold, where the invariant mass of the $tW$ system approaches the collider energy. We employ the reverse unitarity technique and integration-by-parts identities to reduce soft loop integrals to a minimal basis of master integrals. These master integrals are analytically evaluated using the method of differential equations, yielding results expressed in terms of multiple polylogarithms. Additionally, we analyze the asymptotic behavior of the soft function in the low and high energy limits. Our results provide a vital component for threshold resummation at the next-to-next-to-next-to-leading logarithmic level in this process.

   hep-phJHEP(2025)·3 citations
2. 02*

   Machine Learning Approaches to Top Quark Flavor-Changing Four-Fermion Interactions in Trilepton Signals at the LHC

   Meisam Ghasemi Bostanabad🇮🇷 · Mojtaba Mohammadi Najafabadi🇮🇷

   We explore the top quark flavor-changing 4-Fermi interactions ($tuee$ and $tcee$) with scalar, vector, and tensor structures using machine learning models to analyze tri-lepton processes at the LHC. The study is performed using $t\bar{t}$ and $tW$ processes, where a top quark decays into $u/c+e^{+}+e^{-}$. The analysis incorporates both reducible and irreducible backgrounds while accounting for realistic detector effects. The dominant backgrounds for these trilepton signatures arise from $t\bar{t}$ production, single top quark production in association with $V$, and $VV$ production (where $V=W,Z$). These backgrounds are significantly reduced using machine learning-based classification models, which optimize event selection and improve signal sensitivity. For an integrated luminosity of 3000 fb${}^{-1}$ at the LHC, we find that the expected $95\%$ confidence level (CL) limits on the scale of 4-Fermi FCNC interactions reach $\Lambda \le 5.5$ TeV for $tuee$ and $\Lambda \le 5.7$ TeV for $tcee$ in the $t\bar{t}$ channel, and $\Lambda \le 1.9$ TeV ($tuee$) and $\Lambda \le 2.0$ TeV ($tcee$) in the $tW$ channel. We also provide an interpretation of our EFT analysis in the context of a specific $Z^{\prime }$ model, illustrating how the derived constraints translate into bounds on the parameter space of a heavy neutral gauge boson mediating flavor-changing interactions.

   hep-phPRD(2025)·4 citations
3. 03*

   Quarkonium Polarization Kinetic Equation from Open Quantum Systems and Effective Field Theories

   Di-Lun Yang🇹🇼 · Xiaojun Yao🇺🇸

   Recent measurements of polarization phenomena in relativistic heavy ion collisions have aroused a great interest in understanding dynamical spin evolution of the QCD matter. In particular, the spin alignment signature of $J/\psi$ has been recently observed in Pb-Pb collisions at LHC, which may infer nontrivial spin transport of quarkonia in quark gluon plasmas. Motivated by this, we study the spin-dependent in-medium dynamics of quarkonia by using the potential nonrelativistic QCD (pNRQCD) and the open quantum system framework. By applying the Markovian approximation and Wigner transformation, we systematically derive the Boltzmann transport equation for vector quarkonia with polarization dependence in the quantum optical limit. As opposed to the previous study for the spin-independent case where the collision terms depend on chromoelectric correlators, the new kinetic equation incorporates gauge invariant correlators of chromomagnetic fields that determine the recombination and dissociation terms with polarization dependence at the order we are working in the multipole expansion. In the quantum Brownian motion limit, the Lindblad equation with new transport coefficients defined in terms of the chromomagnetic field correlators have also been derived. Our formalism is generic and valid for both weakly-coupled and strongly-coupled quark gluon plasmas. It may be further applied to study spin alignment of vector quarkonia in heavy ion collisions.

   hep-phnucl-thPoS(2025)·0 citations
4. 04*

   $keV$ sterile neutrino as dark matter in doublet left-right symmetric model with $A_4$ modular symmetry

   Ankita Kakoti🇮🇳 · Mrinal Kumar Das🇮🇳

   Left-Right Symmetric Model(LRSM) in this work is extended with a sterile fermion per generation, the lightest of the same is considered to be a suitable dark matter candidate for the study and analysis of the associated properties. The model has been realized using $A_4$ modular symmetry, the advantage being the non-requirement of the use of extra fields, hence keeping the model minimal. Because of the extension of LRSM with the sterile fermion, the neutrino mass in this work will be generated by the double seesaw mechanism as described thoroughly within the manuscript. And for phenomenological studies, we have considered neutrinoless double beta decay the details of which have been discussed thoroughly within the work.

   hep-phPTEP(2025)·0 citations
5. 05*

   A hybrid model for multi-particle production and multi-fragment emission in electron-nucleus collisions at the forthcoming Electron-Ion Collider

   Ting-Ting Duan🇨🇳 · Sahanaa Büriechin🇨🇳 · Hai-Ling Lao🇨🇳 · Fu-Hu Liu🇨🇳 · Khusniddin K. Olimov🇺🇿

   To present a prediction of the multi-particle production and multi-fragment emission in electron-nucleus ($eA$) collisions at the forthcoming Electron-Ion Collider (EIC), a simple hybrid model which is based on the multi-source thermal model and the ideal gas model is proposed in this article. According to the hybrid model, some statistical laws such as the two-component Erlang distribution and others are presented, which means a two-source production. These statistical laws are hopeful to describe the bulk properties of multiple particles produced in the scattering of electron-nucleon ($eN$) and multiple fragments emitted in the fragmentation of excited residual nucleus. Although both the scattering and fragmentation can occur in $eA$ collisions at the EIC, their two-sources are different. In $eN$ scattering, the multiple particles come from the soft excitation and hard scattering processes respectively, which are classified as two different types of events. In nuclear fragmentation, the multiple fragments come from the cold and hot sources which exist in the same excited nucleus.

   hep-phhep-exnucl-exnucl-thMod.Phys.Lett.A(2025)·0 citations
6. 06*

   Interplay of ALP Couplings at a Muon Collider

   So Chigusa🇺🇸 · Sudhakantha Girmohanta🇨🇳 · Yuichiro Nakai🇨🇳 · Yufei Zhang🇨🇳

   Axion-like particles can couple to Standard Model gluons, electroweak gauge bosons, and massive fermions. A future multi-TeV muon collider provides a favorable environment to probe axion-like particles through multiple production channels, including vector boson fusion via electroweak gauge boson couplings and the top-associated production mediated by direct fermionic couplings. Motivated by the quality issue of the QCD axion, we focus on axion-like particles with masses and decay constants around the TeV scale. We explore how different axion-like particle couplings shape its production and decay modes, revealing a rich and intricate phenomenological landscape.

   hep-phhep-exhep-thJHEP(2025)·4 citations
7. 07*

   Axion Emission from Proton Cooper Pairs in Neutron Stars

   Koichi Hamaguchi🇯🇵 · Natsumi Nagata🇯🇵 · Jiaming Zheng🇨🇳

   We investigate axion emission from singlet proton Cooper pairs in neutron stars, a process that dominates axion emission in young neutron stars in the KSVZ model. By re-deriving its emissivity, we confirm consistency with most existing literature, except for a recent study that exhibits a different dependence on the effective mass. This discrepancy results in more than an order-of-magnitude deviation in emissivity, significantly impacting constraints on the KSVZ axion from the cooling observations of the Cassiopeia A neutron star. Furthermore, we examine uncertainties arising from neutron-star equations of state and their role in the discrepancy, finding that the large deviation persists regardless of the choice of equations of state.

   hep-phJCAP(2025)·3 citations
8. 08*

   Demonstrating the ability of IceCube DeepCore to probe Earth's interior with atmospheric neutrino oscillations

   Sharmistha Chattopadhyay🇺🇸 · Krishnamoorthi J🇺🇸 · Anuj Kumar Upadhyay (For the IceCube Collaboration)🇺🇸

   The IceCube Neutrino Observatory is an optical Cherenkov detector instrumenting one cubic kilometer of ice at the South Pole. The Cherenkov photons emitted following a neutrino interaction are detected by digital optical modules deployed along vertical strings within the ice. The densely instrumented bottom central region of the IceCube detector, known as DeepCore, is optimized to detect GeV-scale atmospheric neutrinos. As upward-going atmospheric neutrinos pass through Earth, matter effects alter their oscillation probabilities due to coherent forward scattering with ambient electrons. These matter effects depend upon the energy of neutrinos and the density distribution of electrons they encounter during their propagation. Using simulated data at the IceCube Deepcore equivalent to its 9.3 years of observation, we demonstrate that atmospheric neutrinos can be used to probe the broad features of the Preliminary Reference Earth Model. In this contribution, we present the preliminary sensitivities for establishing the Earth matter effects, validating the non-homogeneous distribution of Earth's electron density, and measuring the mass of Earth. Further, we also show the DeepCore sensitivity to perform the correlated density measurement of different layers incorporating constraints on Earth's mass and moment of inertia.

   hep-phhep-exphysics.geo-phphysics.ins-detEur.Phys.J.ST(2025)·9 citations
9. 09*

   Scaling for count-in-cell and factorial moment analysis

   Valeria Zelina Reyna Ortiz🇵🇱 · Maciej Rybczynski🇵🇱 · Zbigniew Wlodarczyk🇵🇱

   The investigation of remnants associated with the QCD chiral critical point is a primary objective in high-energy ion collision experiments. Numerous studies indicate that a scaling relation between higher-order factorial moments of hadron multiplicity distributions and the second factorial moment may serve as a diagnostic tool for identifying the QCD critical point. However, we demonstrate that this scaling behavior is not exclusive to critical phenomena but rather arises as a general consequence of the phase-space partitioning procedure employed in the analysis. This finding is examined in the context of recent intermittency analyses conducted by the STAR experiment at RHIC.

   hep-phNPB(2025)·2 citations
10. 10*

    Updating TMD parton densities in a proton within the Kimber-Martin-Ryskin approach

    A.V. Kotikov🇷🇺 · A.V. Lipatov🇷🇺

    We present analytical expressions for the Transverse Momentum Dependent (TMD, or unintegrated) gluon and quark densities in a proton derived at leading order of QCD running coupling and valid at both small and large x. The calculations are performed using the Kimber-Martin-Ryskin/Watt-Martin-Ryskin prescription (in both differential and integral formulations) with different treatment of kinematical constraint, which reflects the angular and strong ordering conditions for parton emissions. As an input, analytical solution of QCD evolution equations for conventional (collinear) parton distributions is applied, where the valence and non-singlet quark parts obey the Gross-Llewellyn-Smith and Gottfried sum rules and momentum conservation for the singlet quark and gluon densities is taken into account. Several phenomenological parameters are extracted from combined fit to precision data on the proton structure function $F_2(x,Q^2)$ collected by the BCDMS, H1 and ZEUS Collaborations, comprising a total of 933 points from 5 data sets. Comparison with the numerical results obtained by other groups is presented and phenomenological application to the inclusive b-jet production at the LHC is given.

    hep-phPRD(2025)·5 citations
11. 11*

    Chiral Representation of the Nucleon Mass at Leading Two-loop Order

    Ze-Rui Liang🇨🇳 · Han-Xue Chen🇨🇳 · Feng-Kun Guo🇨🇳 · Zhi-Hui Guo🇨🇳 · De-Liang Yao🇨🇳

    We calculate the nucleon mass in a manifestly relativistic baryon chiral perturbation theory up to the leading two-loop order. Through dimensional counting analysis, we perform the chiral expansion and verify the validity of the extended-on-mass-shell scheme at the two-loop level. As a result, we obtain the complete chiral representation of the nucleon mass up to $\mathcal{O}(p^5)$, which preserves the original analytic properties and satisfies the correct power counting. The obtained chiral result is well-suited for chiral extrapolation and provides an excellent description of lattice QCD data across a broad range of pion masses. We find that the $\mathcal{O}(p^5)$ contribution is small, approximately $10$ MeV, and varies only mildly with increasing pion mass, demonstrating good convergence of the nucleon mass up to pion masses of about 350 MeV at two-loop order.

    hep-phhep-latnucl-thJHEP(2025)·8 citations
12. 12*

    Towards the strong decays of light strange four-quark states with $J^P=1^{+}$

    Ye Xing🇨🇳 · Zhi-Peng Xing🇨🇳 · Yu-Ji Shi🇨🇳

    This thesis considers the decays of fully light four quark exotic as the main subject. In the context, we study the possible decays from general symmetric analysis: $uu\bar{d}\bar{s}$, $dd\bar{s}\bar{u}$, $ds\bar{u}\bar{u}$, and $su\bar{d}\bar{d}$. Using the light quark flavor symmetry, we discuss the decay modes of decuplet and 27 multiplet with $J^P=1^{+}$. Further more, the phenomenological hadronic molecular approach is employed for the calculation of respective decay modes. Our results show that the total decay widths of $T_{\rho K}$ and $S_{\rho K^{\ast }}$ can reach several MeV. The two-body and three-body decay widths are further obtained respectively. These are excepted to be fairly valuable supports for future search experiments.

    hep-ph0 citations
13. 13*

    Search for oscillating fundamental constants using a paired detector and vibrational spectroscopy

    René Oswald🇩🇪 · Victor Vogt🇩🇪 · Stephan Schiller🇩🇪

    Ultralight dark matter (UDM) may manifest itself through oscillating fundamental constants of normal matter. These can be experimentally searched for by implementing two dissimilar oscillators producing a beat between their frequencies and analyzing the beat-frequency time series for the presence of any temporal oscillations. Typically, the time series of such a detector contains contributions from nonstationary noise. In order to reduce the influence of such noise we propose and demonstrate paired detectors: two nominally identical detectors whose signals are synchronously recorded. The cross-spectrum of the two individual beat time series is then analyzed for UDM signatures. This approach permits us to suppress spurious signals appearing in uncorrelated fashion in either detector. We furthermore demonstrate detectors that are based on a vibrational molecular transition, which are advantageous due to their larger sensitivity to oscillations of the nuclear masses. The analysis of 274 hours of data yielded improved bounds for the coupling constants of UDM to nuclear mass and to electron mass in the frequency ranges 10-500 Hz and 10-122 kHz, with improvement factors between 6 and 10. These bounds are currently the strongest. Similar bounds are obtained for the fine-structure constant. The present approach may be generalized to large ensembles of detectors.

    hep-phquant-phPRD(2025)·4 citations
14. 14*

    Chiral vortical conductivities and the moment of inertia of a rigidly rotating Fermi gas

    M. Abedlou Ahadi🇮🇷 · N. Sadooghi🇮🇷

    We determine the chiral vortical conductivities, as well as the orbital and spin moment of inertia of a charged, chiral, and rigidly rotating free Fermi gas. To this purpose, we begin by calculating the vacuum expectation values of a vector and axial vector current using the free fermion propagator in this medium. This propagator is derived by employing the Fock-Schwinger method based on the solutions of the Dirac equation in the presence of rotation and finite axial chemical potential. We present a complete derivation of these solutions. We demonstrate that in the first approximation, the chiral vortical conductivity associated with the vector current is proportional to the product of the vector and axial chemical potentials. In contrast, the chiral vortical conductivity related to the axial vector current depends on the temperature, the vector, and the axial vector chemical potential squares. We use the relation between the axial vector current and the angular momentum density associated with spin to determine the spin and the orbital moment of inertia of a rigidly rotating Fermi gas in a charged and chirally imbalanced medium separately. In addition, we compute the total moment of inertia by utilizing the methods presented in the first part of the paper and show that the orbital moment of inertia of a free fermion gas vanishes.

    hep-phcond-mat.quant-gasnucl-thPRD(2025)·5 citations
15. 15*

    Cosmological Magnetic Fields from Ultralight Dark Matter

    Robert Brandenberger🇨🇦 · Jürg Fröhlich🇨🇭 · Hao Jiao (McGill and ETH Zurich)🇨🇦

    We propose a mechanism for the generation of magnetic fields on cosmological scales that is operative after recombination. An essential ingredient is an instability (of parametric resonance type) of the electromagnetic field driven by an oscillating pseudo-scalar dark matter field, $\varphi$, that is coupled to the electromagnetic field tensor via a $\varphi F\wedge F$ term in the Lagrangian of axion-electrodynamics. We find that magnetic fields larger than the observational lower bounds can be generated soon after recombination on scales of $1\mathrm{Mpc}$.

    hep-phastro-ph.COgr-qchep-thPRL(2026)·18 citations
16. 16*

    Topological Susceptibility in the Superconductive Phases of Quantum Chromodynamics: a Dyson-Schwinger Perspective

    Fabrizio Murgana🇮🇹 · Giorgio Comitini🇮🇹 · Marco Ruggieri🇮🇹

    We test non-perturbative gluon propagators recently studied in the literature, by computing the topological susceptibility, $\chi$, of the superconductive phases of Quantum Chromodynamics at high density. We formulate the problem within the High-Density Effective Theory, and use the 2-particle irreducible formalism to compute the effective potential of the dense phases. We focus on superconductive phases with two and three massless flavors. Within this formalism, we write a Dyson-Schwinger equation in the rainbow approximation for the anomalous part of the quark propagator in the superconductive phases, in which the non-perturbative gluon propagator plays its role. We complete the model by adding a $U(1{)}_A$-breaking term whose coupling is fixed perturbatively at large quark chemical potential. We then use the effective potential to compute $\chi$ in the superconductive phases. We finally discuss implications of the results for the axion mass in superdense phases of Quantum Chromodynamics.

    hep-phhep-thnucl-thPRD(2025)·4 citations
17. 17*

    Correlation function for the $p{f}_1(1285)$ interaction

    Pablo Encarnación🇪🇸 · Albert Feijoo🇪🇸 · Eulogio Oset🇪🇸

    We have addressed here the problem of calculating the correlation function of a stable particle with a resonance, in particular one resonance that qualifies as a molecular state of two components. The formalism used requires to evaluate the scattering matrix of the stable particle with the molecule, a nuclear problem which we address by means of the fixed center approximation. We have applied the method to the interaction of a proton with the $f_1(1285)$ resonance, presently under investigation by the ALICE collaboration, where the $f_1(1285)$ is taken as a $K^{\ast }\bar{K}-{\bar{K}}^{\ast }K$ molecule. We find that the $p{f}_1(1285)$ interaction develops a resonance state below the $p{f}_1(1285)$ threshold, which leads to a depletion in the $p{f}_1(1285)$ correlation function for small values of the proton momentum. The discussion presented shows that these type of studies can provide much information on the nature of some resonances and the existence of three-body bound states involving mesons and baryons.

    hep-phnucl-thPRD(2025)·13 citations
18. 18*

    Probing a low-mass $Z^{\prime }$ gauge boson at IceCube and prospects for IceCube-Gen2

    Reinaldo Francener🇧🇷 · Victor P. Goncalves🇧🇷 · Diego R. Gratieri🇧🇷

    In this work, we investigate the impact of the $L_{\mu }-L_{\tau }$ model, which predicts a new massive gauge boson, $Z^{\prime }$, on astrophysical neutrino events at the IceCube Observatory. This new gauge boson couples with leptons from the second and third families, and would break the power law of the astrophysical neutrino flux due to the interaction of this flux with the cosmic neutrino background. We derive the sensitivity of the IceCube to this model considering the HESE data from 12 years of observation by assuming different assumptions for the redshift distributions of astrophysical neutrino sources, mass ordering, and sum of neutrino masses. Our results indicate that the current IceCube data is able to probe small coupling and masses of the order of some few MeV, with the covered parameter space being larger if a distribution of neutrino sources is described by the star formation rate model. In addition, we demonstrate that the IceCube-Gen2 will cover a large region of the parameter space and will allow us to improve our understanding of the $L_{\mu }-L_{\tau }$ model.

    hep-phastro-ph.HEhep-exPRD(2025)·2 citations
19. 19*

    Collinear and TMD distributions with dynamical soft-gluon resolution scale

    F. Hautmann🇧🇪 · L. Keersmaekers🇧🇪 · A. Lelek🇧🇪 · S. Sadeghi Barzani🇮🇷 · S. Taheri Monfared🇩🇪

    Soft-gluon resolution scales characterize parton branching Monte Carlo implementations of the evolution equations for parton distribution functions in Quantum Chromodynamics (QCD). We examine scenarios with dynamical, i.e., branching-scale dependent, resolution scale, and discuss physical implications for both collinear and transverse-momentum dependent (TMD) distributions. We perform the first determination of parton distributions with dynamical resolution scale, at next-to-leading order (NLO) in perturbation theory, from fits to precision deep-inelastic scattering measurements from HERA. We present an application of TMD distributions with dynamical resolution scale to Drell-Yan lepton-pair transverse momentum spectra at the LHC, and comment on the extraction of non-perturbative intrinsic-kT parameters from Drell-Yan data at small transverse momenta.

    hep-phJHEP(2025)·7 citations
20. 20*

    Comment on "Dark Energy from Time Crystals"

    James M. Cline🇨🇦

    It was recently proposed (arxiv:2502.08887) that the time crystal Lagrangian introduced by Shapere and Wilczek in 2012 could be a model of dark energy. I point out that the model has an instability that drives its energy density to negative values, which may render it unsuitable as a model of dark energy.

    hep-phgr-qchep-th2 citations
21. 21*

    Neutrino-Nucleus Cross Section Impacts on Neutrino Oscillation Measurements

    Nina M. Coyle🇺🇸 · Shirley Weishi Li🇺🇸 · Pedro A. N. Machado🇺🇸

    The challenges in neutrino-nucleus cross section modeling and its impact on neutrino oscillation experiments are widely recognized. However, a comprehensive and theoretically robust estimation of cross section uncertainties has been lacking, and few studies have quantitatively examined their impact on oscillation measurements. In this work, we evaluate the effect of cross section uncertainties on oscillation parameters using setups inspired by NOvA and DUNE. To characterize these uncertainties, we adopt multiple neutrino-nucleus event generators and simulate a realistic experimental procedure that incorporates near-detector data and near-to-far-detector extrapolation. Our results confirm that cross section uncertainties cannot significantly bias oscillation results in current statistics-dominated experiments like NOvA. However, they could lead to substantial bias for future systematics-dominated experiments like DUNE, even when near-detector data are employed to mitigate uncertainties. These findings underscore the need for further studies on the quantitative impacts of cross section modeling, improved strategies to utilize near-detector data and the PRISM concept, and more robust cross section models to optimize the success of future experiments.

    hep-phPRD(2025)·17 citations
22. 22*

    Detecting Supernova Axions with IAXO

    P. Carenza🇸🇪 · J. A. García Pascual🇪🇸 · M. Giannotti🇪🇸 · I. G. Irastorza🇪🇸 · M. Kaltschmidt🇪🇸 · A. Lella🇮🇹 · A. Lindner🇩🇪 · G. Lucente🇺🇸 · A. Mirizzi🇮🇹 · M. J. Puyuelo🇪🇸 · T. Schiffer🇩🇪

    We investigate the potential of IAXO and its intermediate version, BabyIAXO, to detect axions produced in core-collapse supernovae (SNe). Our study demonstrates that these experiments have realistic chances of identifying SN axions, offering crucial insights into both axion physics and SN dynamics. IAXO's sensitivity to SN axions allows for the exploration of regions of the axion parameter space inaccessible through solar observations. In addition, in the event of a nearby SN, $d\sim O(100)$ pc, and sufficiently large axion couplings, $g_{a\gamma }\gtrsim 10^{-11}Ge{V}^{-1}$, IAXO could have a chance to significantly advance our understanding of axion production in nuclear matter and provide valuable information about the physics of SNe, such as pion abundance, the equation of state, and other nuclear processes occurring in extreme environments.

    hep-phastro-ph.HEastro-ph.SRhep-exJCAP(2025)·15 citations
23. 23*

    Sub-GeV dark matter and nano-Hertz gravitational waves from a classically conformal dark sector

    Sowmiya Balan🇩🇪 · Torsten Bringmann🇳🇴 · Felix Kahlhoefer🇩🇪 · Jonas Matuszak🇩🇪 · Carlo Tasillo🇩🇪

    Strong first-order phase transitions in a dark sector offer a compelling explanation for the stochastic gravitational wave background in the nano-Hertz range recently detected by pulsar timing arrays (PTAs). We explore the possibility that such a phase transition at the same time gives mass to a stable fermion that accounts for the observed dark matter abundance and leads to testable effects in laboratory experiments. Concretely, we consider a classically conformal dark sector with a hidden $U(1{)}^{\prime }$ gauge symmetry that couples to the Standard Model via kinetic mixing. Since the PTA signal requires a phase transition in the MeV temperature range, spontaneous symmetry breaking gives rise to a sub-GeV dark matter candidate that couples to the Standard Model via a dark photon mediator and obtains its relic abundance via annihilations into electrons and dark Higgs bosons. Such a scenario is tightly constrained by laboratory searches for dark photons and cosmological constraints on the decays of dark Higgs bosons after the phase transition. We show that viable parameter regions can be found both for the case that the dark Higgs bosons remain in equilibrium with the Standard Model and that they decouple and only decay much later. In the latter case, the parameter regions preferred by the PTA signal and the dark matter relic abundance can be fully explored by future beam-dump experiments searching for missing energy.

    hep-phastro-ph.COJCAP(2025)·40 citations
24. 24*

    Misconceptions in Neutrino Oscillations in presence of a non-Unitary Mixing

    Mattias Blennow🇸🇪 · Pilar Coloma🇪🇸 · Enrique Fernández-Martínez🇪🇸 · Josu Hernández-García🇪🇸 · Jacobo López-Pavón🇪🇸 · Xabier Marcano🇪🇸 · Daniel Naredo-Tuero🇪🇸 · Salvador Urrea🇫🇷

    Deviations from unitarity of the CKM matrix in the quark sector are considered excellent windows to probe physics beyond the Standard Model. In its leptonic counterpart, the PMNS matrix, these searches are particularly motivated, as the new physics needed to generate neutrino masses often leads to non-unitary mixing among the standard neutrinos. It is then interesting to consider how neutrino oscillations are affected in such scenario. This simple question is, however, subject to several subtleties: What is the correct way to define oscillation probabilities for a non-unitary mixing matrix? Do these probabilities add up to one? Does a non-unitary mixing matrix lead to observable flavor transitions at zero distance? What is the interplay between unitarity constraints obtained from neutrino oscillations and from electroweak precision data? This work aims to shed light on these issues and to clarify the corresponding misconceptions commonly found in the literature. We also compile updated bounds from neutrino oscillation searches to compare with those from flavour and electroweak precision observables.

    hep-phhep-exNPB(2025)·10 citations
25. 25*

    Extended IDM theory with low scale seesaw mechanisms

    D. T. Huong🇻🇳 · A.E. Cárcamo Hernández🇨🇱 · H. T. Hung🇻🇳 · T. T. Hieu🇻🇳 · Nicolás A. Pérez-Julve🇨🇱 · N. T. Duy🇻🇳

    We have developed an extension of the inert doublet model in which the CP-phases in the weak sector are generated from one-loop level corrections mediated by dark fields, while the strong-CP phase arises at three-loop. In this framework, the tiny masses of the active neutrinos are produced through a radiative inverse seesaw mechanism at a two-loop level, the masses of the first and second families of SM-charged fermions arise from a one-loop level radiative seesaw mechanism, and the third generation of SM charged fermion masses are generated at tree level. We have demonstrated that the proposed model successfully accounts for SM fermion masses and mixings. The radiative nature of the seesaw mechanisms is attributed to preserved discrete symmetries, which are required for ensuring the stability of fermionic and scalar dark matter candidates. The preserved discrete symmetries also allow for multi-component dark matter, whose annihilation processes permits to successfully reproduce the measured amount of dark matter relic abundance for an appropriate region of parameter space, which has shown to be compatible with current dark matter direct detection limits. Besides that, we explore the model's ability to explain the $95$ GeV diphoton excess observed by the CMS collaboration, showing that it readily accommodates this anomaly. We have shown that charged lepton flavor violating decays acquire rates within the current experimental sensitivity.

    hep-phPRD(2026)·5 citations
26. 26*

    Theoretical and Experimental Constraints on ${\mathbb{Z}}_{2n}$ Multi-Component Dark Matter Models

    J. P. Carvalho-Corrêa🇧🇷 · I. M. Pereira🇧🇷 · B. L. Sánchez-Vega🇧🇷 · A. C. D. Viglioni🇧🇷

    A complete assessment of any dark matter model requires confronting its low-energy phenomenology with its high-scale theoretical viability. We undertake such a dual analysis for a class of two-component scalar dark matter models stabilized by ${\mathbb{Z}}_{2n}$ symmetries, specifically the ${\mathbb{Z}}_4$, ${\mathbb{Z}}_6(23)$, and ${\mathbb{Z}}_6(13)$ frameworks. Each model is tested against the latest observational data, including the Planck relic abundance and stringent direct detection limits from the LUX-ZEPLIN (LZ) experiment. Simultaneously, we evaluate their theoretical integrity up to the GUT and Planck scales by enforcing vacuum stability and perturbative unitarity with one-loop Renormalization Group Equations. This combined approach reveals a rich and varied landscape of possibilities. We demonstrate that the ${\mathbb{Z}}_4$ model offers a broadly viable parameter space sustained by efficient semi-annihilation. In stark contrast, the ${\mathbb{Z}}_6(13)$ scenario is shown to be highly fine-tuned, with solutions confined to the Higgs resonance. Our most significant finding concerns the ${\mathbb{Z}}_6(23)$ model: we show that an apparent conflict between experimental data and high-scale consistency is resolved when the model is viewed as an effective field theory, yielding a concrete prediction for new physics at or below the $10^6$ GeV scale. This work provides a definitive guide to the viability of these ${\mathbb{Z}}_{2n}$ scenarios and serves as a compelling demonstration of how high-energy consistency checks can yield crucial insights into the nature of dark matter.

    hep-phEPJC(2025)·3 citations
27. 27*

    Axion Portal to Scalar Dark Matter: Unveiling Stabilizing Symmetry Footprints

    Francesco D'Eramo🇮🇹 · Tommaso Sassi🇮🇹

    We investigate the role of an axion-like particle (ALP) as a portal between the dark and visible sectors. Unlike conventional studies, which typically assume fermionic dark matter (DM), we explore the phenomenological implications of scalar DM within this ALP portal framework. A key challenge arises from the fact that the interaction between the ALP spacetime derivative and the spin-one current of the scalar DM can be a redundant operator, which may be removed via a field redefinition. However, this interaction reveals a profound connection to the underlying global symmetry that stabilizes the DM particle. We choose a non-Abelian discrete symmetry, ensuring the persistence of the DM-ALP interactions, and in doing so, unveil a rich phenomenology. Working within a general effective field theory approach, we identify the following hallmark features of our scenario: (i) a relic density determined by semi-annihilations, with an abundance independent of ALP couplings to the visible sector; (ii) direct detection rates naturally suppressed; (iii) indirect detection spectra enriched relative to pure annihilation scenarios, with rates also independent of ALP couplings to visible particles. Lastly, we discuss potential microscopic origins for this framework and highlight the broader implications of our results.

    hep-phastro-ph.COJHEP(2025)·8 citations
28. 28*

    A Louder Gravitational Wave Bang from a Fast-Expanding Universe

    Lucas Brown🇺🇸 · Stefano Profumo🇺🇸 · Aditi Gangadharan🇺🇸 · Zeynep Su Koç🇹🇷

    A strong first-order phase transition in a dark sector may produce all or part of the low-frequency gravitational wave signal recently reported by the NANOGrav Collaboration and other pulsar timing arrays. Here we point out, with a simple toy model, that even if the amplitude of the gravitational wave background from the dark phase transition is insufficient to match the NANOGrav signal, a modified expansion rate at early times may considerably enhance the gravitational wave signal. In particular, a faster-than-standard expansion rate, triggered, for instance, by the presence of one or more additional sources of energy density redshifting with higher powers of temperatures than radiation, boosts upper limits on the gravitational wave signal from first-order cosmological phase transitions, enlarging the slate of possible dark sector scenarios matching the NANOGrav signal.

    ↳ astro-ph.COhep-phhep-thPRD(2025)·1 citation
29. 29*

    Ab Initio Calculations of the Carbon and Oxygen Isotopes: Energies, Correlations, and Superfluid Pairing

    Young-Ho Song · Myungkuk Kim · Youngman Kim🇰🇷 · Kihyeon Cho🇰🇷 · Serdar Elhatisari🇹🇷 · Dean Lee🇺🇸 · Yuan-Zhuo Ma🇺🇸 · Ulf-G. Meißner🇩🇪

    We perform \textit{ab initio} nuclear lattice calculations of the neutron-rich carbon and oxygen isotopes using high-fidelity chiral interactions. We find good agreement with the observed binding energies and compute correlations associated with each two-nucleon interaction channel. For the isospin $T=1$ channels, we show that the dependence on $T_z$ provides a measure of the correlations among the extra neutrons in the neutron-rich nuclei. For the spin-singlet S-wave channel, we observe that any paired neutron interacts with the nuclear core as well as its neutron pair partner, while any unpaired neutron interacts primarily with only the nuclear core. For the other partial waves, the correlations among the extra neutrons grow more slowly and smoothly with the number of neutrons. These general patterns are observed in both the carbon and oxygen isotopes and may be universal features that appear in many neutron-rich nuclei.

    ↳ nucl-thhep-phnucl-exPLB(2026)·8 citations
30. 30*

    Implications of {\sigma}-cut potential on Antikaon condensates in neutron stars

    Prashant Thakur🇮🇳 · Yashmitha Kumaran🇲🇽 · Lakshana Sudarsan🇬🇧 · Krishna Kunnampully🇬🇧 · B. K. Sharma🇮🇳 · T. K. Jha🇮🇳

    We investigate the properties of neutron stars with antikaon condensation in the framework of the Relativistic Mean-Field (RMF) model with a $\sigma$-cut potential. The well-known RMF models, TM1 and TM1e, are used to analyze the structure and composition of neutron stars. The antikaon condensation part of the equation of state (EoS) is constrained from the experimental data of K${}^{-}$ atomic and kaon-nucleon scattering. The $\sigma$-cut potential, which is known to make the EoS stiffer at high densities, is modulated by a free parameter $f_s$. Our present analysis suggests that one can obtain neutron star configurations heavier than 2$M_{\odot }$ with antikaon condensates in most cases for $f_s$ = 0.6. The antikaon phase transition is a second-order for $f_s$ = 0.6 for both TM1 and TM1e parameter sets. The calculated global properties of neutron stars with antikaon condensates i.e., mass and radius seem to be in resonable agreement with other theoretical and observational data.

    ↳ astro-ph.HEgr-qchep-phnucl-thPRC(2025)·6 citations
31. 31*

    Higher derivative holography and temperature dependence of QGP viscosities

    Thomas Apostolidis🇫🇷 · Umut Gürsoy🇳🇱 · Edwan Préau🇳🇱

    Recent Bayesian analyses of heavy ion collision data have established a non-trivial temperature dependence of the shear and bulk viscosity per entropy. Motivated by this, we consider higher derivative corrections to realistic, bottom-up holographic models of quark-gluon plasma based on five-dimensional Einstein-dilaton theories and determine the dilaton potentials in the higher derivative terms by matching the Bayesian analyses. A byproduct of our analysis is the bulk viscosity that follows from the holographic V-QCD theory. Higher derivative corrections when treated perturbatively lead to tension with existing data. We investigate possible resolutions.

    ↳ hep-thhep-exhep-phnucl-thJHEP(2025)·4 citations
32. 32*

    Chiral symmetry breaking and restoration by helical magnetic fields in AdS/CFT

    Martí Berenguer🇪🇸 · Javier Mas🇪🇸 · Masataka Matsumoto🇨🇳 · Keiju Murata🇯🇵 · Alfonso V. Ramallo🇪🇸

    We study the effects of helical magnetic fields on chiral symmetry breaking within the AdS/QCD framework using the D3/D7-brane model. By analyzing the brane embeddings, we obtain three types of massless solutions, corresponding to three phases with different behavior in the dual field theory. From the study of quark condensates, free energy, and electric currents, we find that helical magnetic fields can counteract uniform-field-induced symmetry breaking, driving the system towards symmetry restoration. We also find an effect analog to the chiral magnetic effect whereby the current is parallel to the magnetic field. We further study the massive case, and find that the helical configuration is less effective in erasing the first order phase transition that is present in the case of a constant magnetic field.

    ↳ hep-thgr-qchep-phJHEP(2025)·7 citations
33. 33*

    Light dilaton near critical points in top-down holography

    Daniel Elander🇵🇹 · Antón F. Faedo🇪🇸 · Maurizio Piai🇬🇧 · Ronnie Rodgers🇸🇪 · Javier G. Subils🇳🇱

    We study a class of UV-complete, strongly coupled, confining three-dimensional field theories, that exhibit a novel stabilisation mechanism for the mass of the lightest scalar composite state, relying on the existence of a critical point. The theories admit a holographic dual description in terms of regular backgrounds in eleven-dimensional supergravity. Their phase diagram includes a line of first-order phase transitions ending at the critical point, where the transition becomes of second order. We calculate the mass spectrum of bound states of the field theory, by considering fluctuations around the background solutions, and find that, near the critical point, a hierarchy of scales develops, such that one state becomes parametrically light. We identify this state as the dilaton, the pseudo-Nambu-Goldstone boson associated with the spontaneous breaking of approximate scale invariance. This stabilisation mechanism might be exploited to address hierarchy problems in particle and astroparticle physics.

    ↳ hep-thhep-phPRD(2025)·9 citations
34. 34*

    A strike of luck: could the KM3-230213A event be caused by an evaporating primordial black hole?

    Andrea Boccia🇮🇹 · Fabio Iocco🇮🇹

    We investigate whether the ultra high energy neutrino inferred by the recent KM3NeT observation could have originated from an evaporating black hole. Given the characteristics of black hole (BH) evaporation mechanism, any object capable of producing particles in the energy range of the detected event (around 100-800 PeV) must have a mass below 10^7 g. No known astrophysical mechanism can generate black holes of such low mass, leaving primordial black holes (PBHs)-potentially formed at the end of cosmic inflation-as the only viable candidates. Black holes with masses below 10^7 g have lifetimes shorter than 10^-5 seconds, meaning PBHs in this mass range should have fully evaporated by now. However, recent studies suggest that quantum effects, collectively referred to as the "memory burden", may slow down black hole evaporation, potentially extending the lifetimes of low-mass PBHs to timescales comparable to or exceeding the Hubble time. We systematically explore the parameter space of memory-burdened PBHs, assuming that they constitute a fraction of the dark matter (f-PBH) within current constraints, and identify viable regions that could explain the KM3-230213A event. We further predict the occurrence rate of similar events and find that KM3NeT's current configuration could test this scenario within a few years.

    ↳ astro-ph.HEastro-ph.COhep-phPRD(2025)·54 citations
35. 35*

    Self-Similar Structure of Loop Amplitudes and Renormalization

    Kang-Sin Choi🇰🇷

    We study the self-similar structure of loop amplitudes in quantum field theory and apply it to amplitude generation and renormalization. A renormalized amplitude can be regarded as an effective coupling that recursively appears within another loop. It is best described as a vertex function from the effective action. It is a scale-dependent, finite, parametrically small and observable quantity appearing in the S-matrix. Replacing a tree-level coupling with a loop amplitude provides a systematic method of generating high-order loop amplitudes, guaranteeing no subamplitude divergence. This method also provides an alternative bottom-up proof to the traditional top-down recursive renormalization of general amplitudes.

    ↳ hep-thhep-ph4 citations
36. 36*

    Work and heat exchanged during sudden quenches of strongly coupled quantum systems

    Zohreh Davoudi🇺🇸 · Christopher Jarzynski🇺🇸 · Niklas Mueller🇺🇸 · Greeshma Oruganti🇺🇸 · Connor Powers🇺🇸 · Nicole Yunger Halpern🇺🇸

    How should one define thermodynamic quantities (internal energy, work, heat, etc.) for quantum systems coupled to their environments strongly? We examine three (classically equivalent) definitions of a quantum system's internal energy under strong-coupling conditions. Each internal-energy definition implies a definition of work and a definition of heat. Our study focuses on quenches, common processes in which the Hamiltonian changes abruptly. In these processes, the first law of thermodynamics holds for each set of definitions by construction. However, we prove that only two sets obey the second law. We illustrate our findings using a simple spin model. Our results guide studies of thermodynamic quantities in strongly coupled quantum systems.

    ↳ quant-phcond-mat.stat-mechhep-lathep-ph+1PRE(2026)·10 citations
37. 37*

    Three-Body Non-Locality in Particle Decays

    Paweł Horodecki🇵🇱 · Kazuki Sakurai🇵🇱 · Abhyoudai S. Shaleena🇵🇱 · Michael Spannowsky🇬🇧

    The exploration of entanglement and Bell non-locality among multi-particle quantum systems offers a profound avenue for testing and understanding the limits of quantum mechanics and local real hidden variable theories. In this work, we examine non-local correlations among three massless spin-1/2 particles generated from the three-body decay of a massive particle, utilizing a framework based on general four-fermion interactions. By analyzing several inequalities, we address the detection of deviations from quantum mechanics as well as violations of two key hidden variable theories: fully local-real and bipartite local-real theories. Our approach encompasses the standard Mermin inequality and the tight $4\times 4\times 2$ inequality, providing a comprehensive framework for probing three-partite non-local correlations. Our findings provide deeper insights into the boundaries of classical and quantum theories in three-particle systems, advancing the understanding of non-locality in particle decays and its relevance to particle physics and quantum foundations.

    ↳ quant-phhep-exhep-phhep-thJHEP(2025)·13 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.