Fri·Feb 7, 2025Friday·February 7, 2025

1. 01*

   Complementary Probes of Warped Extra Dimension: Colliders, Gravitational Waves and Primordial Black Holes from Phase Transitions

   Anish Ghoshal🇵🇱 · Eugenio Megias🇪🇸 · Germano Nardini🇳🇴 · Mariano Quiros🇪🇸

   We study the formation of primordial black holes (PBHs) and stochastic gravitational waves background (SGWB) produced by the supercooled radion phase transition (PT) in warped extra-dimension models solving the gauge hierarchy problem. We first determine how the SGWB and the produced PBH mass and abundance depend on the warped model's infrared energy scale $\rho$, and the number of holographic colors $N$. With this finding, we recast on the plane $\{\rho ,N\}$ the current SGWB and PBH constraints, as well as the expected parameter reaches of GW detectors, as LISA and ET, and the gravitational lensing ones, such as NGRST. On the same plane, we also map the collider bounds on massive graviton production, and cosmological bounds on the radion phenomenology. We find that, for $N\sim 10-50$, the considered PT predicts a PBH population mass in the range $M_{\mathrm{PBH}}\sim (10^{-1}-10^{-25})M_{\odot }$ for $\rho \sim (10^{-4}-10^8)\text{ TeV}$. In the range $\rho \simeq (0.05-0.5)$ GeV, it can explain the recent SGWB hint at nHz frequencies and generate PBH binaries with mass $M_{\mathrm{PBH}}\sim (0.1-1)M_{\odot }$ detectable at LISA and ET. The experimentally allowed mass region where PBHs can account for the whole dark matter abundance, and are produced with a tuning $\lesssim 10^{-4}$, corresponds to $10$ TeV $\lesssim \rho \lesssim$ $10^4$ TeV. These PBHs can compensate the lack of natural candidates for dark matter in warped extra dimensional models. Such a region represents a great science case where forthcoming and future colliders like HE-LHC and FCC-hh, gravitational-wave observatories and other PBHs probes play a key complementary role.

   hep-phastro-ph.COJHEP(2025)·7 citations
2. 02*

   Higgs Thermal Nonequilibrium in Primordial QGP

   Cheng Tao Yang🇺🇸 · Shelbi Foster🇺🇸 · Johann Rafelski🇺🇸

   In this work we investigate the chemical and kinetic nonequilibrium dynamics of the Higgs boson during the primordial Universe QGP (quark-gluon plasma) epoch $130\mathrm{GeV}>T>10\mathrm{GeV}$. We show that the Higgs bosons is always out of chemical abundance equilibrium with a fugacity ${{\rm Y}}_h=0.69$ due to virtual decay channels. Additionally, Higgs momentum distribution is found to be ``cold'' for $T<25$\,GeV, since the scattering rate drops below the production rate.

   hep-phastro-ph.COnucl-thEur.Phys.J.ST(2025)·1 citation
3. 03*

   Investigating the 95 GeV Higgs Boson Excesses within the I(1+2)HDM

   Ayoub Hmissou🇲🇦 · Stefano Moretti🇬🇧 · Larbi Rahili🇲🇦

   In this work, we explore how the 2-Higgs Doublet Model (2HDM) Type-I, extended by an inert doublet, can provide an explanation for the recently observed excesses at the Large Hadron Collider (LHC) in the $\gamma \gamma$ and ${\tau }^{+}{\tau }^{-}$ final states. Hence, by imposing theoretical constraints and experimental bounds on the model parameter space, our findings show that a light CP-even Higgs boson, $h$, with a mass around 95 GeV, can account for these anomalies. This result aligns with the excess in $b\bar{b}$ signatures reported in earlier data from the Large Electron-Positron (LEP) collider.

   hep-phPRD(2026)·9 citations
4. 04*

   Sensitivity to Triple Higgs Couplings via Di-Higgs Production in the RxSM at the (HL-)LHC and future $e^{+}{e}^{-}$ Colliders

   F. Arco🇩🇪 · S. Heinemeyer🇪🇸 · M. Mühlleitner🇩🇪 · A. Parra Arnay🇪🇸 · N. Rivero González🇪🇸 · A. Verduras Schaeidt🇩🇪

   The real Higgs singlet extension of the Standard Model (SM) without $Z_2$ symmetry, the RxSM, is the simplest extension of the SM that features a First Order Electroweak Phase Transition (FOEWPT) in the early universe. The FOEWPT is one of the requirements needed for electroweak baryogenesis to explain the baryon asymmetry of the universe (BAU). Thus, the RxSM is a perfect example to study features related to the FOEWPT at current and future collider experiments. The RxSM has two CP-even Higgs bosons, $h$ and $H$, with masses $m_h<m_H$, where we assume that $h$ corresponds to the Higgs boson discovered at the LHC. Our analysis is based on a benchmark plane that ensures the occurence of a strong FOEWPT, where $m_H>2m_h$ is found. In a first step we analyze the di-Higgs production at the (HL-)LHC, $gg\to hh$, with a focus on the impact of the trilinear Higgs couplings (THCs), ${\lambda }_{hhh}$ and ${\lambda }_{hhH}$. The interferences of the resonant $H$-exchange diagram involving ${\lambda }_{hhH}$ and the non-resonant diagrams result in a characteristic peak-dip (or dip-peak) structure in the $m_{hh}$ distribution. We analyze how ${\lambda }_{hhH}$ can be accessed, taking into account the experimental smearing and binning. We also demonstrate that the approximation used by ATLAS and CMS for the resonant di-Higgs searches may fail to capture the relevant effects and lead to erroneous results. In a second step we analyze the benchmark plane at a future high-energy $e^{+}{e}^{-}$ collider with $\sqrt{s}=1000$ GeV (ILC1000). We demonstrate the potential sensitivity to ${\lambda }_{hhH}$ via an experimental determination at the ILC1000.

   hep-phJHEP(2025)·16 citations
5. 05*

   First-order CP phase transition in two-flavor QCD at $\theta =\pi$ under electromagnetic scale anomaly via a Nambu-Jona-Lasinio description

   Yuanyuan Wang🇨🇳 · Shinya Matsuzaki🇨🇳 · Mamiya Kawaguchi🇨🇳 · Akio Tomiya🇯🇵

   We discuss the thermal CP phase transition in QCD at $\theta =\pi$ under a weak magnetic field background, where the electromagnetic scale anomaly gets significant. To explicitize, we work on a two-flavor Nambu-Jona-Lasinio model at $\theta =\pi$ in the mean field approximation, including the electromagnetic-scale anomaly term. We find that the thermal CP phase transition becomes first order and the strength of the first order gets more prominent as the magnetic field increases. The associated potential barrier is thermally created by the electromagnetic scale anomaly and gives rise to criticality due to the induced potential of a non-perturbative form $\sim \frac{|eB{|}^3}{f_{\pi }}\frac{|P|}{P^2+m_0^2}$, where $eB$ denotes the magnetic field strength; $P$ the CP order parameter, and $m_0$ the isospin-symmetric current-quark mass.

   hep-phhep-lathep-thnucl-thPRD(2025)·1 citation
6. 06*

   Renormalization group invariant mean-field model for QCD at finite isospin density

   Bastian B. Brandt🇩🇪 · Volodymyr Chelnokov🇩🇪 · Gergely Endrodi🇩🇪 · Gergely Marko🇩🇪 · Daniel Scheid🇩🇪 · Lorenz von Smekal🇩🇪

   QCD at nonzero isospin chemical potentials has phenomenological relevance for a series of physical systems and provides an ideal testground for the modeling of dense strongly interacting matter. The two-flavor quark-meson model is known to effectively describe the condensation of charged pions in QCD that occurs in this setting. In this paper, we derive a renormalization-group invariant mean-field formulation of the model and demonstrate that the resulting phase diagram and equation of state are in quantitative agreement with data from lattice QCD simulations at small and intermediate isospin chemical potentials. In particular, the speed of sound from the model shows an excess over the conformal bound as previously seen in lattice computations in agreement with chiral perturbation theory. We then consider the speed of sound in the limit of large isospin chemical potentials and see that it approaches the conformal limit from above, in qualitative agreement with recent lattice results and in quantitative agreement with perturbation theory in the presence of a BCS gap. Finally, we consider the phase diagram in the approach to the chiral limit. We find that within the model the chiral phase transition connects to the pion condensation phase boundary in the chiral limit and we discuss the implications for the properties of the chiral transition point.

   hep-phhep-latnucl-thPRD(2025)·24 citations
7. 07*

   New axion contribution to the two-photon decays of neutral pions

   Zhen-Yan Lu🇨🇳 · Yang Huang🇨🇳 · Ji-Gui Cheng🇨🇳 · Qi Lu🇨🇳 · Shu-Peng Wang🇨🇳

   The presence of axions introduces new diagrams at one-loop order to the two-photon decays of the neutral pion through axion-pion mixing. In this work, we calculate this correction, missing in all current calculations, in the framework of SU(2) chiral perturbation theory. We show that the correction is proportional to the axion-photon coupling and the square of axion mass, which in turn is strongly suppressed by the axion decay constant for the classical space window but may not be negligible for the QCD axion in the MeV or even larger mass range. On the other hand, in combination with the experimental measurement of the decay width of ${\pi }^0\to \gamma \gamma$ process, this result rules out the standard QCD axion as an explanation for the possible discrepancy between the chiral perturbation theory prediction and the experimental data.

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

   The Cabibbo-favored hadronic weak decays of the ${\Xi }_c$ in the quark model

   Peng-Yu Niu🇨🇳 · Qian Wang🇨🇳 · Qiang Zhao🇨🇳

   The Cabibbo-favored hadronic weak decay of the ${\Xi }_c^{+}\to {\Xi }^0{\pi }^{+}$, ${\Xi }_c^0\to {\Xi }^{-}{\pi }^{+}$, ${\Xi }_c^0\to {\Xi }^0{\pi }^0$, ${\Xi }_c^0\to {\Xi }^0{\eta }^{{(}^{\prime })}$ and ${\Xi }_c^0\to {\Xi }^{+}{K}^{-}$ are studied in the non-relativistic constituent quark model. By analyzing their decay mechanisms at the quark level we show that the pole terms are essential for understanding the transition dynamics in addition to the usually considered direct meson emission process and color suppressed process in the charmed baryon hadronic weak decays. The experimentally measurable asymmetry parameters are also predicted in order to further pin down the decay mechanism.

   hep-phPRD(2025)·8 citations
9. 09*

   Can a secluded self-interacting dark sector generate detectable gravitational waves?

   Song Li🇨🇳 · Jin Min Yang🇨🇳 · Mengchao Zhang🇨🇳 · Yang Zhang🇨🇳 · Rui Zhu🇨🇳

   In this work we study the possibility to detect the gravitational waves generated by a secluded self-interacting dark sector. ``Secluded'' means that the dark sector has almost no portal to the visible sector and thus its entropy is conserved by itself, and ``self-interacting'' means that dark matter in this model has a significant interaction to itself, making it consistent with the small-scale structure observations. A spontaneously broken $U(1{)}^{\prime }$ is introduced for the interactions in the dark sector, and nearly massless dark radiation is also introduced to avoid the over-closure problem. Through a parameter space scan, we find that this model is highly constrained by the currently observed effective number of neutrinos ($N_{\text{eff}}$) and the large-scale structure observable Lyman-$\alpha$. Together, these two constraints exclude a large parameter space that is favored by future gravitational-wave detectors, but there is still a small portion of the model parameter space that can be detected by SKA.

   hep-phastro-ph.HEJHEP(2026)·4 citations
10. 10*

    A Neural-Network Extraction of Unpolarised Transverse-Momentum-Dependent Distributions

    Alessandro Bacchetta🇮🇹 · Valerio Bertone🇫🇷 · Chiara Bissolotti🇺🇸 · Matteo Cerutti🇺🇸 · Marco Radici🇮🇹 · Simone Rodini🇩🇪 · Lorenzo Rossi🇮🇹

    We present the first extraction of transverse-momentum-dependent distributions of unpolarised quarks from experimental Drell-Yan data using neural networks to parametrise their nonperturbative part. We show that neural networks outperform traditional parametrisations providing a more accurate description of data. This work establishes the feasibility of using neural networks to explore the multi-dimensional partonic structure of hadrons and paves the way for more accurate determinations based on machine-learning techniques.

    hep-phhep-exPRL(2025)·60 citations
11. 11*

    Systematic Analysis of $B_s\to SP$ Decays in Perturbative QCD Approach

    Zhi-Tian Zou🇨🇳 · Zhao-Xu He🇨🇳 · Ya-Xin Wang🇨🇳 · Ying Li🇨🇳

    Within the perturbative QCD (PQCD) framework, we present a systematic investigation of charmless $B_s\to SP$ decays, where $S$ and $P$ denote scalar and pseudoscalar mesons, respectively. By employing two distinct structural scenarios for scalar mesons, we calculate the branching fractions and direct $CP$ asymmetries for these processes. Our results reveal branching fractions ranging from $10^{-7}$ to $10^{-5}$, values that are well within the measurable range of current experiments. A striking contrast emerges between penguin- and tree-dominated decays: while penguin-dominated processes yield larger branching fractions, tree-dominated decays exhibit significantly enhanced direct $CP$ asymmetries. In particular, the decays $B_s\to f_0(1370)\eta$ and $B_s\to a_0(1450)K$ demonstrate marked sensitivity to the choice of scalar meson scenario, offering critical constraints for identifying the optimal model once experimental data are available. Furthermore, we calculate the branching fractions of $B_s\to f_0(980)(\sigma )P$ decays in two distinct ranges of the mixing angle of $f_0(980)-\sigma$. The dependencies of both branching fractions and $CP$ asymmetries on this mixing angle are rigorously analyzed, establishing a framework essential for determining its value with future experimental results. These findings provide a robust theoretical foundation for advancing the understanding of nonleptonic $B_s$decays in QCD-based formalisms, as well as the nature of scalar mesons.

    hep-phhep-exEPJC(2025)·1 citation
12. 12*

    Landau-Khalatnikov-Fradkin Transformations in Quantum Electrodynamics: For Perturbation Theory and Dynamical Mass Generation

    Anam Ashraf🇵🇰 · M. Jamil Aslam🇵🇰 · Faisal Akram🇵🇰 · Adnan Bashir🇪🇸

    We carry out a comprehensive analysis of the Landau-Khalatnikov-Fradkin transformations for a charged fermion propagator at the two-loop level in quantum electrodynamics (QED). Starting with an arbitrary covariant gauge $\xi$ and space-time dimension $d$, we provide its explicit expressions in three and four-dimensional QED. We begin with the tree-level fermion propagator in the Landau gauge and gauge-transform it to obtain an analytical expression for an all order result in an arbitrary covariant gauge. We expand it out to two-loops both for the massless and massive propagators in three and four space-time dimensions. In addition to comparing with all earlier results in the literature wherever possible, we also study constraints of multiplicative renormalizabilty of our results in four-dimensional QED which are logarithmically divergent. Finally, we analyze representative solutions of the fermion propagator which correspond to dynamical chiral symmetry breaking and mass generation in QED. We study the gauge dependence of these emergent solutions, that of the Euclidean pole mass and the chiral fermion condensate.

    hep-phhep-thnucl-thPRD(2025)·0 citations
13. 13*

    Fermion Dark Matter Effect on Electroweak Phase Transition

    Soudeh Mirzaie🇮🇷 · Karim Ghorbani🇮🇷 · Parsa Ghorbani🇮🇷

    The addition of extra scalars to the Standard Model (SM) of particle physics enriches the vacuum structure and consequently gives rise to strong first-order phase transitions (EWPT) in the early universe. We raise the question that how the EWPT is affected by the addition of fermions in models beyond the SM, and address this question by studying the EWPT in a dark matter model comprising a singlet scalar and two Dirac fermions. The singlet scalar develops a nonzero vacuum expectation value (VEV), and the lighter fermion plays the role of the dark matter. The model evades the stringent direct detection bounds due to the presence of two fermions. We first show that applying the high-temperature approximation, no first-order phase transition is found. Then we demonstrate that when including the full finite temperature corrections to the effective potential, the first-order phase transition becomes possible, nevertheless, all the phase transitions will be weak. We therefore deduce that the addition of fermions reduces the strength of the EWPT.

    hep-phEPJC(2025)·3 citations
14. 14*

    Establishing the vector-meson-exchange dominance for the short range interactions of light quarks

    Bing-Song Zou🇨🇳

    I give a brief comment on a recent study revealing the vector meson exchange (VME) dominant for the short range interactions between u/d quarks in the $NN$, $D_{03}$, and $D_{30}$ systems. The finding echoes nicely with an earlier study of hadron spectroscopy using a quark model with hidden local symmetry which also favors the VME dominant for the short range interactions of light quarks. The VME dominance for the short range interactions of light quarks gives a natural explanation of the empiric VME dominance for the interactions between hadrons containing light quarks.

    hep-phnucl-thSCPMA(2025)·3 citations
15. 15*

    Searching for coupled, hyperlight scalars across cosmic history

    Masha Baryakhtar🇺🇸 · Olivier Simon🇺🇸 · Zachary J. Weiner🇺🇸

    Cosmological scalar fields coupled to the Standard Model drive temporal variations in the fundamental constants that grow with redshift, positioning the early Universe as a powerful tool to study such models. We investigate the dynamics and phenomenology of coupled scalars from the early Universe to the present to consistently leverage the myriad searches for time-varying constants and the cosmological signatures of scalars' gravitational effects. We compute the in-medium contribution from Standard Model particles to the scalar's dynamics and identify only a limited range of couplings for which the scalar has an observable impact on the fundamental constants without either evolving before recombination or gravitating nonnegligibly. We then extend existing laboratory and astrophysical bounds to the hyperlight scalar regime. We present joint limits from the early and late Universe, specializing to hyperlight, quadratically coupled scalars that modulate the mass of the electron or the strength of electromagnetism and make up a subcomponent of the dark matter today. Our dedicated analysis of observations of the cosmic microwave background, baryon acoustic oscillations, and type Ia supernovae provides the most stringent constraints on quadratically coupled scalars with masses from $10^{-28.5}$ to $\sim 10^{-31}\mathrm{eV}$, below which quasar absorption spectra yield stronger bounds. These results jointly limit hyperlight scalars that comprise a few percent of the current dark matter density to near- or subgravitational couplings to electrons or photons.

    hep-phastro-ph.COPRD(2025)·18 citations
16. 16*

    Higgs-Induced Gravitational Waves: the Interplay of Non-Minimal Couplings, Kination and Top Quark Mass

    Giorgio Laverda🇵🇹 · Javier Rubio🇪🇸

    We explore a minimal scenario where the sole Standard-Model Higgs is responsible for reheating the Universe after inflation, produces a significant background of gravitational waves and maintains the full classical stability of the electroweak vacuum. As the Higgs self-coupling runs toward negative values at high energy scales, a non-minimal interaction with curvature during a stiff background expansion era drives the Higgs fluctuations closer to the instability scale. This curvature-induced tachyonic instability leads to an intense production of Higgs particles, accompanied by a stochastic gravitational-wave background. The characteristic features of such signal can be directly correlated to the inflationary scale, the non-minimal coupling parameter and the top quark Yukawa coupling. We distinguish between three possible scenarios: absolute stability with low top quark masses, potential vacuum instability, and absolute stability with new physics above the instability scale. Our findings suggest that the detection of a peaked background of gravitational waves together with its inflationary tail has the potential to unveil the features of the Higgs effective potential at very high energy scales while providing a minimal explanation for the reheating phase and the emergence of the Standard-Model plasma in the early Universe. Unlike other studies in the literature, the generation of gravitational waves in our scenario does not depend on the quantum instability of the Standard Model vacuum.

    hep-phastro-ph.COgr-qcJHEP(2025)·12 citations
17. 17*

    Primordial Gravitational Waves in Quadratic Gravity

    Jisuke Kubo🇩🇪 · Jeffrey Kuntz🇩🇪

    Quadratic gravity is a fourth-order (in derivatives) theory that can serve as an attractive upgrade to the standard description of gravity provided by General Relativity, thanks to its renormalizability and its built-in description of primordial inflation. We bring quadratic gravity into a second-order form by introducing an auxiliary tensor field and we consider the primordial tensor fluctuations (gravitational waves) in the theory around a Friedmann-Lemaître-Robertson-Walker background. After a canonical quantization of the perturbations, we calculate the tensor power spectrum in quasi de Sitter spacetime. We find that the spectral index $n_t$ and the amplitude $A_t$ of the tensor power spectrum are both suppressed by the factor $(1+2{\mathbf{H}}_{\ast }^2/m_{\text{gh}}^2{)}^{-1}$, where ${\mathbf{H}}_{\ast }$ is the Hubble rate at horizon exit and $m_{\text{gh}}$ is the mass of the spin-two ghost. This restores the slow-roll consistency condition familiar from single-field inflation models, where the tensor-to-scalar ratio $r$ is equal to $-8n_t$ in the lowest nontrivial order in the slow-roll approximation. We also discuss the well-known issue of the ghost problem in fourth-order theories and how it pertains to the results at hand.

    ↳ gr-qcastro-ph.COhep-phJCAP(2025)·8 citations
18. 18*

    Complementary signatures of $\alpha -$attractor inflation in CMB and cosmic string Gravitational Waves

    Mainak Baidya🇮🇳 · Anish Ghoshal🇵🇱 · David F. Mota🇳🇴

    When cosmic strings are formed during inflation, they regrow to reach a scaling regime, leaving distinct imprints on the stochastic gravitational wave background (SGWB). Such signatures, associated with specific primordial features, can be detected by upcoming gravitational wave observatories, such as the LISA and Einstein Telescope (ET). Our analysis explores scenarios in which cosmic strings form either before or during inflation. We examine how the number of e-folds experienced by cosmic strings during inflation correlates with the predictions of inflationary models observable in cosmic microwave background (CMB) measurements. This correlation provides a testable link between inflationary physics and the associated gravitational wave signals in a complementary manner. Focusing on $\alpha$-attractor models of inflation, with the Polynomial $\alpha$-attractor serving as an illustrative example, we find constraints, for instance, on the spectral index $n_s$ to $0.962\lesssim n_s\lesssim 0.972$ for polynomial exponent $n=1$, $0.956\lesssim n_s\lesssim 0.968$ for $n=2$, $0.954\lesssim n_s\lesssim 0.965$ for $n=3$, and $0.963\lesssim n_s\lesssim 0.964$ for $n=4$, which along with the GW signals from LISA, are capable of detecting local cosmic strings that have experienced $\sim 34-47$ e-folds of inflation consistent with current Planck data and are also testable in upcoming CMB experiments such as LiteBIRD and CMB-S4.

    ↳ astro-ph.COgr-qchep-phhep-thPRD(2025)·1 citation
19. 19*

    Spectral parameters of the $\rho$ resonance from lattice QCD

    Zhengli Wang🇨🇳 · Derek B. Leinweber🇦🇺 · Chuan Liu🇨🇳 · Liuming Liu🇨🇳 · Peng Sun🇨🇳 · Anthony W. Thomas🇦🇺 · Jia-jun Wu🇨🇳 · Hanyang Xing🇨🇳 · Kang Yu🇨🇳

    We present a lattice QCD investigation of the $\rho$ resonance using nine $N_f=2+1$ Wilson-Clover ensembles with three lattice spacings and various pion masses ranging from $135$ to $320$ MeV. For each ensemble, a large number of finite volume energy levels are determined and the energy dependence of the phase shift obtained from Lüscher's finite volume method. The mass and width of the $\rho$ resonance are then extracted by assuming the Breit-Wigner form. The mass and width are extrapolated to the physical pion mass and continuum limit ($\mathcal{O}(a^2)$) using a linear function of $a^2$ and $m_{\pi }^2$. The extrapolated values for the mass and width in the Breit-Wigner form are $(m_{\rho },{\Gamma }_{\rho })=(781.6\pm 10.0,146.5\pm 9.9)$ MeV, which are in good agreement with experiment. An alternative method of analysis, based on Hamiltonian effective field theory, involves directly fitting the lattice energy levels and accounting for the quark mass dependence of the hadronic loop diagrams which yield the leading and next-to-leading non-analytic behaviour. This approach also yields consistent $\rho$ parameters at the physical point. This represents the most precise determination to date of the mass and width of a hadron which is unstable under strong decay, achieved through comprehensive lattice QCD calculations and methods of analysis.

    ↳ hep-lathep-phJHEP(2025)·13 citations
20. 20*

    HEP-JEPA: A foundation model for collider physics using joint embedding predictive architecture

    Jai Bardhan🇮🇳 · Radhikesh Agrawal🇫🇷 · Abhiram Tilak · Cyrin Neeraj🇮🇳 · Subhadip Mitra🇮🇳

    We present a transformer architecture-based foundation model for tasks at high-energy particle colliders such as the Large Hadron Collider. We train the model to classify jets using a self-supervised strategy inspired by the Joint Embedding Predictive Architecture. We use the JetClass dataset containing 100M jets of various known particles to pre-train the model with a data-centric approach -- the model uses a fraction of the jet constituents as the context to predict the embeddings of the unseen target constituents. Our pre-trained model fares well with other datasets for standard classification benchmark tasks. We test our model on two additional downstream tasks: top tagging and differentiating light-quark jets from gluon jets. We also evaluate our model with task-specific metrics and baselines and compare it with state-of-the-art models in high-energy physics. Project site: https://hep-jepa.github.io/

    ↳ cs.LGhep-exhep-ph23 citations
21. 21*

    Fundamental oscillations as a tool to distinguish boson stars from neutron stars and black holes

    Swarnim Shirke🇮🇳 · Bikram Keshari Pradhan🇮🇳 · Debarati Chatterjee🇮🇳 · Laura Sagunski🇩🇪 · Jürgen Schaffner-Bielich🇩🇪

    Massive boson stars are self-gravitating configurations of self-interacting scalar fields and can be modeled by a massive scalar field with a quartic self-interaction potential. It has been shown that the equation of state and static structure properties, such as mass and radius, follow scaling relations independent of microscopic dark matter properties. In this work, we demonstrate for the first time that non-radial fundamental ($f$-)mode characteristics also follow a scaling in the strong interaction limit, opening up the outstanding prospect of evaluating the mode properties for boson stars for arbitrary masses spanning the scalar dark matter parameter space allowed by current observations. We provide the scaling relations within full general relativity and obtain the mode characteristics corresponding to the maximum boson star mass configuration. We apply these to determine the $f$-mode properties for boson stars solely as a function of their mass and compactness, which allows distinguishing them from those of neutron stars and black hole quasinormal modes in comparable mass range. In particular, we show that the frequencies are always lower than those of corresponding black holes of the same mass by a factor of 4.5. This provides a smoking gun for the distinguishability of boson stars from other compact objects using gravitational wave observations.

    ↳ gr-qcastro-ph.HEhep-phPhys.Dark Univ.(2025)·1 citation
22. 22*

    Detectability of Massive Boson Stars using Gravitational Waves from Fundamental Oscillations

    Swarnim Shirke🇮🇳 · Bikram Keshari Pradhan🇮🇳 · Debarati Chatterjee🇮🇳 · Laura Sagunski🇩🇪 · Jürgen Schaffner-Bielich🇩🇪

    Boson Stars are macroscopic self-gravitating configurations made of complex scalar fields. These exotic compact objects would manifest as dark Boson stars and, in the absence of electromagnetic signatures, could mimic properties of compact stars in the gravitational wave spectrum. In a recent study, using the simplest potential for massive Boson stars, we demonstrated that fundamental non-radial oscillations ($f$-modes) obey scaling relations that allow them to be distinguished from neutron stars and black holes. In this work, we provide analytical fits for these scaling relations, valid for the dark matter parameter space compatible with current astrophysical and cosmological data, that can be directly incorporated into future studies of massive Boson stars in the strong coupling regime, avoiding the need for numerical calculations. We also provide analytical fits for empirical and universal relations for gravitational wave asteroseismology, which can be used to infer microscopic dark matter properties following a successful detection. Further, we investigate the possibility of detection of $f$-modes and the dark matter parameter space that can be probed with current and future gravitational wave detectors across multiple frequency bands. Assuming a burst gravitational wave model and demanding a signal-to-noise ratio of 5, we show that the current and future detectors can, in principle, probe Boson star $f$-modes up to cosmological distances: 1 Mpc with aLIGO, 30 Mpc with Cosmic Explorer and Einstein Telescope, and in the best case scenario, about 300 Mpc with LISA.

    ↳ gr-qcastro-ph.HEhep-phJCAP(2026)·4 citations
23. 23*

    Absence of CP Violation in the Strong Interaction: Vacuum thwarts Axion

    Gerrit Schierholz🇩🇪

    QCD admits a contribution to the action, the $\theta$ term, which potentially gives rise to nontrivial phases and violates CP. This is essentially a question of how the vacuum reacts to the $\theta$ term. In this talk I will address the problem using new developments on the lattice. The overall solution is contrasted with the axion `solution'.

    ↳ hep-lathep-phhep-thnucl-thPoS(2025)·4 citations
24. 24*

    Testing nucleation calculations for strong phase transitions

    Oliver Gould🇬🇧 · Anna Kormu🇫🇮 · David J. Weir🇫🇮

    Accurate calculations of the nucleation rate $\Gamma$ for first order phase transitions are important for determining their observable consequences in particle physics and cosmology. Perturbative calculations are often used, but they are incomplete and should be tested against fully nonperturbative lattice simulations. We simulate nucleation on the lattice in a scalar field theory with a tree-level barrier, a scenario which should be well described by perturbation theory. Our computation of the nucleation rate, however, only shows qualitative agreement with the perturbative result. This motivates further study of nucleation on the lattice and to higher orders in perturbation theory.

    ↳ hep-lathep-phPoS(2025)·3 citations
25. 25*

    $D_1$ and $D_2$ resonances in coupled-channel scattering amplitudes from lattice QCD

    Nicolas Lang🇪🇸 · David J. Wilson🇬🇧

    Isospin-1/2 charmed axial-vector $D^{\ast }\pi -D^{\ast }\eta -D_s^{\ast }\bar{K}$ scattering amplitudes are computed, along with interactions in several other $I=1/2$ $J^P$ channels. Using lattice QCD, we work at a light-quark mass corresponding to $m_{\pi }\approx 391$ MeV, where the lowest three-hadron threshold ($D\pi \pi$) lies high enough to enable a rigorous treatment of this system considering only two-hadron scattering channels. At this light-quark mass, an axial-vector $D_1$ bound state is observed just below $D^{\ast }\pi$ threshold, that is strongly coupled to $D^{\ast }\pi$ in a relative $S$-wave and influences a wide energy region up to the $D^{\ast }\eta$ threshold. An axial-vector $D_1^{\prime }$ resonance is observed in the elastic $D^{\ast }\pi$ energy-region, which is coupled more strongly to $D$-wave $D^{\ast }\pi$. A single narrow tensor state is seen in $J^P=2^{+}$ coupled to both $D\pi$ and $D^{\ast }\pi$. In the region where $D^{\ast }\eta$ and $D_s^{\ast }\bar{K}$ are kinematically open, the available energy levels indicate significant $S$-wave interactions. Upon searching this region for poles, several possibilities exist with large uncertainties. One additional state consistently arises, predominantly coupled to the $S$-wave $D^{\ast }\pi -D^{\ast }\eta -D_s^{\ast }\bar{K}$ amplitudes around the upper energy limit of this analysis.

    ↳ hep-lathep-phJHEP(2025)·13 citations
26. 26*

    Search for hadronic decays of feebly-interacting particles at NA62

    NA62 Collaboration

    The NA62 experiment at CERN has the capability to collect data in a beam-dump mode, where 400 GeV protons are dumped on an absorber. In this configuration, New Physics particles, including dark photons, dark scalars, and axion-like particles, may be produced in the absorber and decay in the instrumented volume beginning approximately 80 m downstream of the dump. A search for these particles decaying in flight to hadronic final states is reported, based on an analysis of a sample of $1.4\times 10^{17}$ protons on dump collected in 2021. No evidence of a New Physics signal is observed, excluding new regions of parameter spaces of multiple models.

    ↳ hep-exhep-phEPJC(2025)·23 citations
27. 27*

    Page Time of Primordial Black Holes in the Standard Model and Beyond

    Yuber F. Perez-Gonzalez🇪🇸

    The Page time marks the moment when the von Neumann entropy of the emitted Hawking radiation equals the Bekenstein-Hawking entropy of an evaporating black hole, which is assumed to quantify its degrees of freedom as seen from the outside. Beyond this point, from unitarity we would expect that the entropy of the radiation begins to decrease, ensuring that information is eventually recovered. In this work, we investigate the dependence of the Page time on black hole properties and the particle content of nature. Specifically, we analyze its sensitivity to the Standard Model (SM) and potential Beyond-the-SM degrees of freedom, incorporating the effects of particle masses. We find that a Schwarzschild primordial black hole (PBH) with an initial mass of $6.23\times 10^{14}\mathrm{g}$ would have a Page time equal to the age of the Universe, assuming emission of SM particles only. We further explore the impact of a non-negligible PBH angular momentum, finding that light spin-2 particles are predominantly emitted before the Page time. Specifically, for initial angular momenta values exceeding $a_{\star }>0.5$, approximately $70\%$ of the total graviton emission occurs prior to the Page time for PBHs with an initial mass $M_{\mathrm{BH}}\lesssim 10^{10}\mathrm{g}$. Finally, we discuss the implications for PBH phenomenology, particularly regarding potential constraints from $\Delta N_{\mathrm{eff}}$ measurements.

    ↳ astro-ph.COgr-qchep-phhep-thPRD(2025)·12 citations
28. 28*

    Searching for Inflationary Physics with the CMB Trispectrum: 1. Primordial Theory & Optimal Estimators

    Oliver H. E. Philcox🇺🇸

    The primordial four-point function encodes a wealth of information about the inflationary Universe. Despite extensive theoretical work, most models of four-point physics have never been compared to data. In this series, we conduct a detailed analysis of Cosmic Microwave Background temperature and polarization trispectra, searching for a wide variety of phenomena including local effects, self-interactions, curvatons, DBI inflation, gauge fields, solid inflation, scalar field exchange, spinning massive field exchange, chiral physics, point sources, and gravitational lensing. After presenting a suite of separable primordial templates, we derive thirteen quasi-optimal estimators that directly estimate the underlying template amplitudes. These are unbiased, minimum variance, mask-deconvolved, and account for correlations between templates (including with lensing). Each estimator can be efficiently implemented using spherical harmonic transforms, Monte Carlo methods, and optimization techniques, and asymptotes to standard forms in certain limits. In Paper 2, we implement these estimators in public code, and in Paper 3, use them to constrain primordial trispectra with Planck data. This enables a wide variety of tests of inflation, including some of the first direct constraints on cosmological collider physics.

    ↳ astro-ph.COgr-qchep-phhep-thPRD(2025)·34 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.