Fri·Oct 25, 2024Friday·October 25, 2024

1. 01*

   Lepton collider as a window to reheating via freezing in dark matter detection. Part II

   Basabendu Barman🇮🇳 · Subhaditya Bhattacharya🇮🇳 · Sahabub Jahedi🇮🇳 · Dipankar Pradhan🇮🇳 · Abhik Sarkar🇮🇳

   Dark matter (DM) genesis via Ultraviolet (UV) freeze-in embeds the seed of reheating temperature and dynamics in its relic density. Thus, discovery of such a DM candidate can possibly open the window for post-inflationary dynamics. However, there are several challenges in this exercise, as freezing-in DM possesses feeble interaction with the visible sector and therefore very low production cross-section at the collider. We show that mono-photon (and dilepton) signal at the ILC, arising from DM effective operators connected to the SM field strength tensors, can still warrant a signal discovery. We study both the scalar and fermionic DM production during reheating via UV freeze-in, when the inflaton oscillates at the bottom of a general monomial potential. Interestingly, we see, right DM abundance can be achieved only in the case of bosonic reheating scenario, satisfying bounds from big bang nucleosynthesis (BBN). This provides a unique correlation between collider signal and the post-inflationary dynamics of the Universe within single-field inflationary models.

   hep-phgr-qchep-exJHEP(2025)·23 citations
2. 02*

   Radiative corrections to the direct detection of the Higgsino-(and Wino-)like neutralino dark matter: Spin-dependent interactions

   Subhadip Bisal🇮🇳 · Arindam Chatterjee🇮🇳 · Debottam Das🇮🇳 · Syed Adil Pasha🇮🇳

   The lightest neutralino (${\tilde{\chi }}_1^0$) is a promising dark matter (DM) candidate in the R-parity conserving minimal supersymmetric standard model (MSSM). In this work, we focus on dominantly Higgsino-like and Wino-like ${\tilde{\chi }}_1^0$ DM, with small admixtures of gauginos and Higgsinos, respectively. In particular, we explore large one-loop corrections to the ${\tilde{\chi }}_1^0{\tilde{\chi }}_1^{0}Z$ vertex, which can significantly affect the estimation of the spin-dependent ${\tilde{\chi }}_1^0$-nucleon scattering cross-section in the regions where such DM candidates are viable. We have used the on-shell renormalization scheme to estimate the relevant counterterm contributions. In the parameter region where ${\tilde{\chi }}_1^0$ is dominantly Higgsino-like, the radiative corrections (including the contributions from the respective counterterms) are substantial and can enhance the ${\tilde{\chi }}_1^0{\tilde{\chi }}_1^{0}Z$ vertex by up to $\sim 120\%$ for the benchmark scenarios we have considered. Further, for an almost pure Wino-like ${\tilde{\chi }}_1^0$, the increment in the ${\tilde{\chi }}_1^0{\tilde{\chi }}_1^{0}Z$ vertex is up to $15\%$. The corresponding cross-sections with the proton and the neutron can be changed by up to about $50\%$. In addition, including the electroweak box diagrams, the cross-sections can be significantly enhanced, in particular, for the Wino-like ${\tilde{\chi }}_1^0$.

   hep-phPRD(2025)·8 citations
3. 03*

   Electroweak renormalization of neutralino-Higgs interactions at one-loop and its impacts on spin-independent direct detection of Wino-like dark matter

   Subhadip Bisal🇮🇳 · Arindam Chatterjee🇮🇳 · Debottam Das🇮🇳 · Syed Adil Pasha🇮🇳

   A Wino-like neutralino dark matter (DM) in the form of the lightest supersymmetric particle (LSP) has been considered one of the popular paradigms that can naturally accommodate {\it new physics} at a relatively higher scale, typically beyond the reach of the LHC. The constraint on the DM relic density typically implies a lightest neutralino mass $\simeq 2$ TeV. Its observational signature through nuclear recoil experiments, specifically involving DM-nucleon spin-independent (SI) scattering, is not impressive, following its high masses and tiny Higgsino fractions. The theoretical calculations can be improved when we compute all the one-loop electroweak (EW) corrections to the three-point vertices for the neutralino (Wino)-Higgs interactions, which in turn boosts the DM-nucleon scattering cross-sections through the SM-like Higgs exchange. Importantly, we include the counterterm contributions. In addition, we incorporate the other next-to-leading order (NLO) EW DM-quark and DM-gluon interactions present in the literature to calculate the DM-nucleon cross-sections. With the improved and precise theoretical estimates, DM-nucleon scattering cross-sections may increase or decrease significantly by more than $100\%$ compared to leading order (LO) cross-sections in different parts of the parameter space.

   hep-phPRD(2025)·3 citations
4. 04*

   Studying the nature of the lightest charmed axial mesons via femtoscopy

   Luciano M. Abreu🇧🇷 · Kanchan P. Khemchandani🇧🇷 · Alberto Martínez Torres🇧🇷 · Fernando S. Navarra🇧🇷

   In this work we discuss how femtoscopic analysis can shed light on the nature of the two lightest axial charmed mesons, denominated as $D_1(2430)$ and $D_1(2420)$, whose masses are similar but widths are different. Their properties are reasonably described taking into account meson-meson coupled channel dynamics and a bare quark-model pole constituting the lowest-order amplitudes. Two different bare quark-model states are used in order to accommodate the different scattering lengths coming from the lattice QCD calculations for the $D\pi$ and $D^{\ast }\pi$ systems and the data from the ALICE Collaboration on the $D\pi$ system. The amplitudes are employed as inputs to determine the correlation functions for the $D^{\ast }\pi$ and $D\rho$ channels and identify the signatures associated with the lowest-lying axial charmed mesons.

   hep-phPoS(2025)·1 citation
5. 05*

   Optimal Equivariant Architectures from the Symmetries of Matrix-Element Likelihoods

   Daniel Maître🇬🇧 · Vishal S. Ngairangbam🇬🇧 · Michael Spannowsky🇬🇧

   The Matrix-Element Method (MEM) has long been a cornerstone of data analysis in high-energy physics. It leverages theoretical knowledge of parton-level processes and symmetries to evaluate the likelihood of observed events. In parallel, the advent of geometric deep learning has enabled neural network architectures that incorporate known symmetries directly into their design, leading to more efficient learning. This paper presents a novel approach that combines MEM-inspired symmetry considerations with equivariant neural network design for particle physics analysis. Even though Lorentz invariance and permutation invariance overall reconstructed objects are the largest and most natural symmetry in the input domain, we find that they are sub-optimal in most practical search scenarios. We propose a longitudinal boost-equivariant message-passing neural network architecture that preserves relevant discrete symmetries. We present numerical studies demonstrating MEM-inspired architectures achieve new state-of-the-art performance in distinguishing di-Higgs decays to four bottom quarks from the QCD background, with enhanced sample and parameter efficiencies. This synergy between MEM and equivariant deep learning opens new directions for physics-informed architecture design, promising more powerful tools for probing physics beyond the Standard Model.

   hep-phcs.LGhep-exphysics.data-anMach.Learn.Sci.Tech.(2025)·12 citations
6. 06*

   Far-from-equilibrium attractors in kinetic theory with two different relaxation times

   Ferdinando Frascà🇮🇹 · Andrea Beraudo🇮🇹 · Michael Strickland

   We solve a Boltzmann equation for massless quark and gluon fluids in a transversally homogeneous, longitudinally boost-invariant expansion. Quarks can be out of chemical equilibrium and the relaxation times of the two species are assumed to be connected by Casimir scaling. We numerically calculate moments of the distribution functions, identifying their early- and late-time attractors and reconstructing also the full distributions. These attractors appear when the system is still far from local thermalization, before hydrodynamics traditionally would be expected to apply. We also analyze the evolution of entropy production for different initial momentum anisotropies and quark abundances.

   hep-phnucl-thPoS(2025)·0 citations
7. 07*

   Top-mass determination from leptonic final states

   Gennaro Corcella🇮🇹

   The top-quark mass is a fundamental parameter of the Standard Model, as it plays a crucial role in the electroweak precision tests, stability of the vacuum and inflation. I review the method and the main results contained in a recent ATLAS analysis which measures the top mass by using the invariant mass of the leptons coming from W and B-hadron decays. The extracted top mass turns out to be the most precise single measurement by ATLAS.

   hep-phEPJ Web Conf.(2024)·0 citations
8. 08*

   Mixing mechanism for the $J^P=0^{+}$ mesons

   Hungchong Kim🇰🇷 · K. S. Kim🇰🇷

   There are three scalar nonets in the Particle Data Group (PDG), one of which includes [$a_0(980),K_0^{\ast }(700)$], another includes [$a_0(1450),K_0^{\ast }(1430)$], and the third includes [$a_0(1710),K_0^{\ast }(1950)$]. Motivated by Ref.[1], we examine an alternative mixing mechanism that could potentially explain the small mass difference between the $a_0(1450)$ and $K_0^{\ast }(1430)$. According to the tetraquark mixing model, two types, distinguished by their color-spin structures, are necessary to describe the tetraquark structure of the two nonets containing [$a_0(980),K_0^{\ast }(700)$] and [$a_0(1450),K_0^{\ast }(1430)$]. Considering the color-spin structures, we argue that the mixing mechanism generating $a_0(1450)$ and $K_0^{\ast }(1430)$ on the one hand, and $a_0(1710)$ and $K_0^{\ast }(1950)$ on the other hand might be relevant for resolving the small mass difference. We also discuss the limitations of other mixing mechanisms that generate the two nonets involving [$a_0(980),K_0^{\ast }(700)$] and [$a_0(1450)$, $K_0^{\ast }(1430)$] or [$a_0(980),K_0^{\ast }(700)$] and [$a_0(1710)$, $K_0^{\ast }(1950)$]

   hep-phhep-exnucl-thPRD(2025)·2 citations
9. 09*

   Renormalization of the pseudoscalar operator at four loops in QCD

   Long Chen🇨🇳 · Michał Czakon🇩🇪 · Marco Niggetiedt🇩🇪

   We present the renormalization constant of the pseudoscalar operator defined with a non-anticommuting ${\gamma }_5$ in dimensional regularization up to four-loop order in perturbative Quantum Chromodynamics (QCD). Furthermore, by virtue of renormalization-group invariance of the relation between the scalar and the pseudoscalar operator, we predict the $\overline{\mathrm{MS}}$ factor of the renormalization constant for the latter at five-loop order in QCD.

   hep-phhep-thJHEP(2024)·1 citation
10. 10*

    Efficient simulation of quarkonium master equation beyond the dipole approximation

    Jorge M. Mtz-Vera🇮🇹 · Andrea Beraudo🇮🇹 · Miguel Ángel Escobedo🇪🇸 · Paolo Parotto🇮🇹 · Michael Strickland

    QTRAJ is a computer code that simulates the propagation of quarkonium in the quark-gluon plasma (QGP) based on the quantum-trajectory algorithm. This algorithm solves a master equation in which the quarkonium is treated as an open quantum system (OQS). A major advantage of this approach is that it turns a 3D spatial evolution for a density matrix into a 1D Schrödinger equation for a wavefunction with a non-hermitian Hamiltonian, drastically reducing the computational cost. So far, the interaction implemented in the master equation was obtained within the framework of potential non-relativistic QCD (pNRQCD), and restricted to the regime $rT\ll 1$, where $r$ is the size of the color dipole and $T$ is the temperature. In the environment produced in heavy-ion collisions (HIC's) this limit is accurate for ${\rm Y}(1S)$, but the applicability to other quarkonium states is dubious. In the present study we generalize the above approach, extending it to the regime $rT\sim 1$ in the one-gluon exchange approximation, with proper Hard Thermal Loop (HTL) resummation of medium effects. This is done by implementing new jump operators connecting different color states of the $Q\bar{Q}$ pair and expanding them in plane waves, giving rise to a variation of the algorithm present in QTRAJ 1.0. Here we provide an overview of this approach comparing the $rT\ll 1$ and $rT\sim 1$ cases, and we discuss prospects for phenomenological application to excited states of bottomonium.

    hep-phnucl-thPoS(2025)·2 citations
11. 11*

    Fermion masses and mixing in SO(10) GUT with a universal two-zero texture

    Gao-Xiang Fang🇨🇳 · Ye-Ling Zhou🇨🇳

    We apply a universal two-zero texture (UTZT) to all mass matrices for matters in their flavour space in SO(10) GUT framework. This texture can be realised by assigning different charge for each family in a $Z_6$ symmetry. By fixing charged fermion masses at their best-fit values, we fit the rest 9 precisely measured observables (three angles and one CP-violating phase in the quark mixing, three angles in the lepton mixing, and two neutrino mass-squared differences) with seven model parameters. The model fits all data of fermion masses and mixing very well and the leptonic CP-violating phase is predicted in the range $(90^{\circ },230^{\circ })$. The model further predicts the right-handed neutrino masses, with the lightest and heaviest of order $10^9$ and $10^{12}$ GeV, respectively. Gauge unification and proton decay have been checked with the assumption of a breaking chain with two intermediate symmetries above the electroweak scale. It indicates that ${\alpha }_{\mathrm{GUT}}$ ranges in (0.022,0.032) as long as the assumption of economical choice of Higgs contents, and $M_{\mathrm{GUT}}$ should be bigger than $4.5\times 10^{15}$ GeV to meet the Super-K bound. We show effective mass $m_{ee}$ for neutrinoless double beta decay, which provides us with a possibility to test grand unification with neutrinoless double beta decay experiments.

    hep-phCPC(2025)·4 citations
12. 12*

    Transport coefficients of chiral fluid dynamics using low-energy effective models

    Pedro Nogarolli🇧🇷 · Gabriel S. Denicol🇧🇷 · Eduardo S. Fraga🇧🇷

    We investigate the first-order transport coefficients of a fluid made of quasiparticles with a temperature-dependent mass extracted from chiral models. We describe this system using an effective kinetic theory, given by the relativistic Boltzmann equation coupled to a temperature-dependent background field determined from the thermal masses. We then simplify the collision term using the relaxation time approximation and implement a Chapman-Enskog expansion to calculate all first-order transport coefficients. In particular, we compute the bulk and shear viscosities using thermal masses extracted from the linear sigma model coupled with constituent quarks and the NJL model.

    hep-phnucl-thPRD(2026)·0 citations
13. 13*

    Six-jet production from triple parton scatterings in proton-proton collisions at the LHC

    Marina Maneyro🇬🇧 · David D'Enterria🇨🇭

    The production of six energetic jets in proton-proton (pp) collisions at the LHC is studied as a means to directly observe for the first time the simultaneous scattering of three partons. The single-parton-scattering (SPS) cross sections for the production 2-, 3-, 4-, and 6-jets in pp collisions at center-of-mass energies of $\sqrt{s}=14$ TeV, are calculated up to next-to-leading-order (NLO) accuracy in perturbative quantum chromodynamics with the MadGraph5_aMC@NLO and ALPGEN codes complemented with Pythia-8 for parton showering, hadronization, and decays. Jets are reconstructed using the anti-$k_T$ algorithm with distance parameter $R=0.4$. Assuming factorization of multiple hard-scattering probabilities in terms of SPS cross sections, the contributions to six-jet production from double- (DPS) and triple- (TPS) parton scatterings are derived. We find that the TPS contributions represent a $\approx 20\%$ ($\approx 1\%$) fraction of the total 6-jets yields for minimum jet transverse momenta of $p_{T,min}=20$ ($40$) GeV. A detailed multivariate analysis with realistic simulations of fully reconstructed jet samples for the TPS signal and DPS and SPS backgrounds indicates that TPS can be observed in events with six jets with $p_{T,min}=40$ GeV each, by collecting an integrated luminosity of $\mathcal{O}(50$ pb${}^{-1}$) in a dedicated low-pileup run at the LHC.

    hep-phhep-exPoS(2025)·3 citations
14. 14*

    A quantum machine learning classifier to search for new physics

    Ji-Chong Yang🇨🇳 · Shuai Zhang🇨🇳 · Chong-Xing Yue🇨🇳

    Due to the success of the Standard Model~(SM), it is reasonable to anticipate that the signal of new physics~(NP) beyond the SM is small. Consequently, future searches for NP and precision tests of the SM will require high luminosity collider experiments. Moreover, as precision tests advance, rare processes with many final-state particles require consideration which demands the analysis of a vast number of observables. The high luminosity produces a large amount of experimental data spanning a large observable space, posing a significant data-processing challenge. In recent years, quantum machine learning has emerged as a promising approach for processing large amounts of complex data on a quantum computer. In this study, we propose quantum searching neighbor~(QSN) and variational QSN~(VQSN) algorithms to search for NP. The QSN is a classification algorithm. The VQSN introduces variation to the QSN to process classical data. As applications, we apply the (V)QSN in the phenomenological study of the NP at the Large Hadron Collider and muon colliders. Examples are implemented on a real quantum hardware, which confirms reliable performance under noisy conditions. The results indicate that the VQSN demonstrates superior efficiency in the sense of computational complexity to a classical counterpart k-nearest neighbor algorithm, even when dealing with classical data.

    hep-phquant-phJHEP(2026)·7 citations
15. 15*

    Phase-space integrals through Mellin-Barnes representation

    Taushif Ahmed🇩🇪 · Syed Mehedi Hasan🇩🇪 · Andreas Rapakoulias🇩🇪

    This letter introduces a novel analytical approach to calculating phase-space integrals, crucial for precision in particle physics. We develop a method to compute angular components using multifold Mellin-Barnes integrals, yielding results in terms of Goncharov polylogarithms for integrals involving three denominators. Our results include expressions for massless momenta up to $\mathcal{O}({ϵ}^2)$ and for one massive momentum up to $\mathcal{O}(ϵ)$. Additionally, we derive recursion relations that reduce integrals with higher powers of denominators to simpler ones. We detail how to combine the angular part with the radial one which requires a careful handling of singularities.

    hep-phhep-thPRD(2025)·8 citations
16. 16*

    Stimulated Emission of Dark Matter via Thermal Scattering: Novel Limits for Freeze-In and eV Cold Dark Matter

    Kodai Sakurai🇯🇵 · Wen Yin🇯🇵

    Recently, one of the present authors noticed a stimulated emission process of bosonic dark matter via the two-body decay of a mother particle in a thermal plasma similar to the operation principle of a laser in 2301.08735. In this paper, we show that in a $2\to 2$ process, including a bosonic final particle (e.g., an axion or dark photon), the stimulated emission occurs as well due to a small angle scattering of the thermal mother particles and thus the phenomenon is more universal. Two important conclusions follow: (1) Care must be taken when studying the freeze-in production of a bosonic dark matter, as the abundance and momentum distribution of dark matter can differ significantly due to this effect. (2) eV-mass-range bosonic dark matter is special and theoretically well-motivated because models for freeze-in or other thermal production of dark matter include the parameter region of cold eV dark matter. We also study the dark matter mass effect for the stimulated emission.

    hep-phastro-ph.COJHEP(2025)·11 citations
17. 17*

    How fast can protons decay?

    Hooman Davoudiasl🇺🇸 · Peter B. Denton🇺🇸

    Current laboratory bounds imply that protons are extremely long-lived. However, this conclusion may not hold for all time and in all of space. We find that the proton lifetime can be $\sim 15$ orders of magnitude shorter in the relatively recent past on Earth, or at the present time elsewhere in the Milky Way. A number of terrestrial and astrophysical constraints are examined and potential signals are outlined. We also sketch possible models that could lead to spatial or temporal variations in the proton lifetime. A positive signal could be compelling evidence for a new long range force of Nature, with important implications for the limitations of fundamental inferences based solely on laboratory measurements.

    hep-phhep-exPRD(2025)·3 citations
18. 18*

    Testing leptogenesis and dark matter production during reheating with primordial gravitational waves

    Basabendu Barman🇮🇳 · Arindam Basu🇮🇳 · Debasish Borah🇮🇳 · Amit Chakraborty🇮🇳 · Rishav Roshan🇬🇧

    We study the generation of baryon asymmetry as well as dark matter (DM) in an extended reheating period after the end of slow-roll inflation. Within the regime of perturbative reheating, we consider different monomial potential of the inflaton field during reheating era. The inflaton condensate reheats the Universe by decaying into the Standard Model (SM) bath either via fermionic or bosonic decay modes. Assuming the leptogenesis route to baryogenesis in a canonical seesaw framework, we consider both the radiation bath and perturbative inflaton decay to produce such RHNs during the period of reheating when the maximum temperature of the SM bath is well above the reheating temperature. The DM, assumed to be a SM gauge singlet field, also gets produced from the bath during the reheating period via UV freeze-in. In addition to obtaining different parameter space for such non-thermal leptogenesis and DM for both bosonic and fermionic reheating modes and the type of monomial potential, we discuss the possibility of probing such scenarios via spectral shape of primordial gravitational waves.

    hep-phastro-ph.COPRD(2025)·16 citations
19. 19*

    Gravitational and electromagnetic Cherenkov radiation constraints in modified dispersion relations

    Mikel Artola🇪🇸 · José A. R. Cembranos🇪🇸 · Prado Martín-Moruno🇪🇸

    Motivated by different approaches to quantum gravity, one could consider that Lorentz invariance is not an exact symmetry of nature at all energy scales. Following this spirit, modified dispersion relations have been used to encapsulate quantum gravity phenomenology. In the present work, we propose a class of Lorentz invariance violating phenomenological dispersion relations, which could be different for each particle species, to study the generalized vacuum Cherenkov radiation process. We identify the kinematic regions where the process is allowed and then compute the energy loss rate due to the emission of vacuum electromagnetic and gravitational Cherenkov radiation. Furthermore, we estimate constraints for the Lorentz invariance breaking parameters of protons and gravitons taking into account the existence (or absence) of vacuum gravitational Cherenkov radiation using ultra high energy cosmic ray detections.

    ↳ gr-qcastro-ph.COastro-ph.HEhep-phPRD(2024)·3 citations
20. 20*

    Thin-wall vacuum decay in the presence of a compact dimension meets the $H_0$ and $S_8$ tensions

    Luis A. Anchordoqui🇺🇸 · Ignatios Antoniadis🇹🇭 · Daniele Bielli🇹🇭 · Auttakit Chatrabhuti🇹🇭 · Hiroshi Isono🇹🇭

    The proposal of a rapid sign-switching cosmological constant in the late universe, mirroring a transition from anti-de Sitter (AdS) to de Sitter (dS) space, has significantly improved the fit to observational data and provides a compelling framework for ameliorating major cosmological tensions, such as the $H_0$ and $S_8$ tensions. An attractive theoretical realisation that accommodates the AdS $\to$ dS transition relies on the Casimir forces of fields inhabiting the bulk of a 5-dimensional (5-dim) set up. Among the fields characterising the dark sector, there is a real scalar field $\varphi$ endowed with a potential holding two local minima with very small difference in vacuum energy and bigger curvature (mass) of the lower one. Shortly after the false vacuum tunnels to its true vacuum state, $\varphi$ becomes more massive and its contribution to the Casimir energy becomes exponentially suppressed. The tunneling process then changes the difference between the total number of fermionic and bosonic degrees of freedom contributing to the quantum corrections of the vacuum energy, yielding the AdS $\to$ dS transition. We investigate the properties of this theoretical realisation to validate its main hypothesis and characterise free parameters of the model. We adopt the Coleman-de Luccia formalism for calculating the transition probability within the thin-wall approximation. We show that the Euclidean bounce configuration that drives the transition between $\varphi$ vacua has associated at least a sixth order potential. We also show that distinctive features of the required vacuum decay to accommodate the AdS $\to$ dS transition are inconsistent with a 5-dim non-compact description of the instanton, for which the bounce is $O(5)$ symmetric, and instead call for a 5-dim instanton with a compact dimension, for which the bounce is $O(4)\times U(1)$ symmetric.

    ↳ hep-thastro-ph.COhep-phJHEP(2025)·29 citations
21. 21*

    Calculation of heavy meson light-cone distribution amplitudes from lattice QCD

    Xue-Ying Han🇨🇳 · Jun Hua🇨🇳 · Xiangdong Ji🇺🇸 · Cai-Dian Lü🇨🇳 · Andreas Schäfer🇩🇪 · Yushan Su🇺🇸 · Wei Wang🇨🇳 · Ji Xu🇨🇳 · Yibo Yang🇨🇳 · Jian-Hui Zhang🇨🇳 · Qi-An Zhang · Shuai Zhao🇨🇳

    We develop an approach for calculating heavy quark effective theory (HQET) light-cone distribution amplitudes (LCDAs) by employing a sequential effective theory methodology. The theoretical foundation of the framework is established, elucidating how the quasi distribution amplitudes (quasi DAs) with three scales can be utilized to compute HQET LCDAs. We provide theoretical support for this approach by demonstrating the rationale behind devising a hierarchical ordering for the three involved scales, discussing the factorization at each step, clarifying the underlying reason for obtaining HQET LCDAs in the final phase, and addressing potential theoretical challenges. The lattice QCD simulation aspect is explored in detail, and the computations of quasi DAs are presented. We employ three fitting strategies to handle contributions from excited states and extract the bare matrix elements. For renormalization purposes, we apply hybrid renormalization schemes at short and long distance separations. To mitigate long-distance perturbations, we perform an extrapolation in $\lambda =z\cdot P^z$ and assess the stability against various parameters. After two-step matching, our results for HQET LCDAs are found in agreement with existing model parametrizations. The potential phenomenological implications of the results are discussed, shedding light on how these findings could impact our understanding of the strong interaction dynamics and physics beyond the standard model. It should be noted, however, that systematic uncertainties have not been accounted for yet.

    ↳ hep-lathep-phPRD(2025)·48 citations
22. 22*

    Conceptual Design of the Muonium-to-Antimuonium Conversion Experiment (MACE)

    Ai-Yu Bai🇨🇳 · Hanjie Cai🇨🇳 · Chang-Lin Chen🇨🇳 · Siyuan Chen🇨🇳 · Xurong Chen🇨🇳 · Yu Chen🇺🇸 · Weibin Cheng🇨🇳 · Ling-Yun Dai🇨🇳 · Rui-Rui Fan🇨🇳 · Li Gong🇨🇳 · Zihao Guo🇨🇳 · Yuan He🇨🇳 and 40 other authors

    The spontaneous conversion of muonium to antimuonium is one of the interesting charged lepton flavor violation phenomena offering a sensitive probe of potential new physics and serving as a tool to constrain the parameter space beyond the Standard Model. The Muonium-to-Antimuonium Conversion Experiment (MACE) is designed to utilize a high-intensity muon beam, a Michel electron magnetic spectrometer, a positron transport system, and a positron detection system, to either discover or constrain this rare process with a conversion probability of $\mathcal{O}(10^{-13})$. This article presents an overview of the theoretical framework as well as a detailed description of the experimental design for the search for muonium-to-antimuonium conversion.

    ↳ hep-exhep-phphysics.acc-phphysics.ins-detNucl.Sci.Tech.(2026)·26 citations
23. 23*

    SKATR: A Self-Supervised Summary Transformer for SKA

    Ayodele Ore🇩🇪 · Caroline Heneka🇩🇪 · Tilman Plehn🇩🇪

    The Square Kilometer Array will initiate a new era of radio astronomy by allowing 3D imaging of the Universe during Cosmic Dawn and Reionization. Modern machine learning is crucial to analyse the highly structured and complex signal. However, accurate training data is expensive to simulate, and supervised learning may not generalize. We introduce a self-supervised vision transformer, SKATR, whose learned encoding can be cheaply adapted for downstream tasks on 21cm maps. Focusing on regression and generative inference of astrophysical and cosmological parameters, we demonstrate that SKATR representations are maximally informative and that SKATR generalises out-of-domain to differently-simulated, noised, and higher-resolution datasets.

    ↳ astro-ph.IMastro-ph.COhep-phSciPost Phys.(2025)·15 citations
24. 24*

    Stability analysis of power-law cosmological models

    Jose Mathew🇮🇳 · A Thariq🇮🇳

    In this paper, we revisit the stability of power-law models, focusing on an alternative approach that differs significantly from the standard approaches used in studying power-law models. In the standard approach, stability is studied by reducing the system of background FRW equations to a one-dimensional system for a new background variable $X$ in terms of the number of e-foldings. However, we rewrote the equations, incorporating $H$ into the system and went on to do the calculations up to the second order. We demonstrate by computing the deviations from the power-law exact solution to second-order in time and show that power-law contraction is never an attractor in time, regardless of parameter values. Our analysis shows that while first-order corrections align with existing interpretations, second-order corrections introduce significant deviations that cannot be explained by a simple time shift that explains the first-order diverging terms. With importance, we note that in the number of e-folds, the system remains an attractor, while in cosmic time, it is unstable. We also support our claim with numerical results. This new insight has broader implications for the study of attractor behaviour of differential equation solutions and raises questions about the stability of scenarios like the ekpyrotic bounce driven by an exponential potential. Our work also hints that the different temporal variables we use might not be equivalent.

    ↳ gr-qcastro-ph.COhep-ph0 citations
25. 25*

    Gravothermalizing into primordial black holes, boson stars, and cannibal stars

    Pranjal Ralegankar🇮🇹 · Daniele Perri🇮🇹 · Takeshi Kobayashi🇮🇹

    Very little is known about the cosmological history from after the end of inflation until Big Bang Nucleosynthesis. Various well-motivated models predict that the universe could have undergone a period of matter domination in this early epoch. We demonstrate that if the particles causing matter domination have self-interactions, they can form halos that undergo a gravothermal collapse. We thus propose a novel scenario for the formation of primordial black holes, which in particular can lie within the asteroid-mass range. We also find that it is not only black holes that can form in the aftermath of a gravothermal evolution. We show that number-changing annihilations of the particles can create sufficient heat to halt the gravothermal evolution, thus forming a ``cannibal star''. Likewise, the pressure from the particle's repulsive self-interactions can form a boson star during a gravothermal evolution. Thus, our study highlights that structure formation in the early universe can have a rich phenomenology.

    ↳ astro-ph.COhep-phPRD(2025)·15 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.