Mon·Dec 30, 2024Monday·December 30, 2024

1. 01*

   The Deconstruction of Flavor in the Privately Democratic Higgs Sector

   Bhubanjyoti Bhattacharya (Lawrence Technological University)🇺🇸 · Suneth Jayawardana (Wayne State University)🇺🇸 · Nausheen R. Shah (Wayne State University)🇺🇸

   The Standard Model (SM) of particle physics fails to explain the observed hierarchy in fermion masses or the origin of fermion-flavor structure. We construct a model to explain these observations in the quark sector. We introduce a spectrum of new particles consisting of six of each -- massive singlet vector-like quarks (VLQs), singlet scalars, and SU(2)-doublet scalars. SM quark masses are generated when the neutral components of the SU(2)-doublet scalars acquire non-zero vacuum expectation values (VEVs). We impose global symmetries to ensure that Yukawa couplings stay roughly flavor diagonal and democratic (of the same order), as well as to suppress tree-level flavor-changing neutral currents. Quark-mass hierarchy then follows from a hierarchy in scalar VEVs. The singlet scalars also acquire weak-scale VEVs. Together with the VLQs, they act as messengers between different generations of quarks in the SM. These messenger particles are responsible for generating the elements of the Cabibbo-Kobayashi-Masakawa (CKM) matrix which depend on the ratios of the singlet VEVs and VLQ masses. Constructed this way, the CKM matrix is found to be \emph{independent} of the SM fermion masses. Using the measured values of the CKM matrix elements and assuming order-one couplings, we derive constraints on the masses of the VLQs and discuss prospects for probing our model in the near future.

   hep-phhep-exJHEP(2026)·0 citations
2. 02*

   Velocity-dependent self-interacting dark matter and composite Higgs

   Martin Rosenlyst🇬🇧

   We show that the mass of a self-interacting dark matter candidate, specifically a Dirac fermion, can be generated by composite dynamics, with a light scalar mediator emerging alongside the Higgs itself as composite particles. These novel models naturally explain the halo structure problems at various scales and alleviates the Standard Model naturalness problem simultaneously. The relic density of the dark matter candidates is particle anti-particle symmetric and due to thermal freeze-out. These models are four-dimensional gauge theories with a minimal number of fermions charged under a new confining gauge group. Finally, we demonstrate that these models satisfy various constraints set by the dark matter relic density, Big Bang Nucleosynthesis, Cosmic Microwave Background, as well as direct and indirect detection experiments.

   hep-phhep-th1 citation
3. 03*

   Spin alignment of vector mesons in local equilibrium by Zubarev's approach

   Shi-Zheng Yang🇨🇳 · Xin-Qing Xie🇨🇳 · Shi Pu🇨🇳 · Jian-Hua Gao🇨🇳 · Qun Wang🇨🇳

   We compute the $00$ element of the spin density matrix, denoted as ${\rho }_{00}$ and called the spin alignment, up to the second order of the gradient expansion in local equilibrium by Zubarev's approach. In the first order, we obtain ${\rho }_{00}=1/3$, meaning that the contributions from thermal vorticity and shear stress tensor are vanishing. The non-vanishing contributions to ${\rho }_{00}-1/3$ appear in the second order of gradients in the Belinfante and canonical cases. We also discuss the properties of the spin density matrix under the time reversal transformation. The effective transport coefficient for the spin alignment induced by the thermal shear stress tensor is T-odd in the first order, implying that the first order effect is dissipative.

   hep-phnucl-thPRD(2025)·11 citations
4. 04*

   Vector and Tensor Spin Polarization for Vector Bosons at Local Equilibrium

   Zhong-Hua Zhang🇨🇳 · Xu-Guang Huang🇨🇳 · Francesco Becattini🇮🇹 · Xin-Li Sheng🇮🇹

   We derive expressions for the vector and tensor components of the spin polarization of massive vector bosons at local thermodynamic equilibrium up to second order in the space-time gradients of the thermodynamic fields pertaining to the canonical stress-energy tensor and spin tensor of the free Proca field. A set of Feynman rules is devised to calculate the Wigner function and the matrix-valued spin-dependent distribution (MVSD) functions order by order in space-time gradients. Due to constraints imposed by time-reversal symmetry, the leading contribution to spin alignment - defined as the 00-component of the tensor polarization - arises from second-order terms in MVSD, for which we provide an analytic formula. We discuss the physical meaning of different contributions to vector and tensor polarization. These formulae provide a prediction of a contribution to the spin alignment which can be compared with the observations in relativistic heavy-ion collisions.

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

   Unveiling E${}_6$SSM Scalar Diquarks at the HL-LHC

   Murad Ali🇷🇼 · Shaaban Khalil🇪🇬 · Stefano Moretti🇬🇧 · Shoaib Munir🇺🇸 · Harri Waltari🇸🇪

   We investigate the phenomenology of scalar diquarks with sub-TeV masses within the framework of the $E_6$ Supersymmetric Standard Model (E${}_6$SSM) at the Large Hadron Collider (LHC). Focusing on the lightest of the six diquarks predicted by the model, we select some representative low masses for them in a parameter space region consistent with experimental constraints from direct searches for additional Higgs boson(s), Cold Dark Matter (CDM), and supersymmetry, as well as from flavor physics analyses. Using Monte Carlo ($MC$) simulations, we assess these benchmark points against the latest LHC results corresponding to an integrated luminosity of 140 fb${}^{-1}$. We further evaluate the signal significance of the pair-production of these diquarks, when each of them decays into $tb$ pairs, at the $\sqrt{s}=13$ TeV LHC Run 3 with design integrated luminosity of 300 fb${}^{-1}$, and also at the 3000 fb${}^{-1}$ High-Luminosity LHC (HL-LHC). Our analysis yields a statistical significance exceeding $3\sigma$ at the HL-LHC for diquark masses up to 1 TeV, indicating promising prospects for their discovery.

   hep-ph1 citation
6. 06*

   Domain walls in Nelson-Barr axion model

   Kai Murai🇯🇵 · Kazunori Nakayama🇯🇵

   We explore a concrete realization of a Nelson-Barr model addressing the strong CP problem with suppressed unfavorable corrections. This model has a scalar field that spontaneously breaks discrete symmetry, and its phase component can naturally be relatively light, which we call the Nelson-Barr axion. It has both a tree-level potential and the QCD instanton-induced potential like the QCD axion, each minimizing at the CP-conserving point. While one potential leads to domain wall formation, the other works as a potential bias. This model provides a natural setup for the collapse of the axion domain walls by a potential bias without spoiling a solution to the strong CP problem. We discuss the cosmological implications of domain wall collapses, including dark matter production and gravitational wave emission.

   hep-phastro-ph.COJHEP(2025)·9 citations
7. 07*

   Comprehensive Bayesian Exploration of Froggatt-Nielsen Mechanism

   Masahiro Ibe🇯🇵 · Satoshi Shirai🇯🇵 · Keiichi Watanabe🇯🇵

   The Froggatt-Nielsen (FN) mechanism successfully explains the hierarchical structure of fermion Yukawa couplings by introducing a U(1) flavor symmetry with distinct charge assignments for different fermion generations. While some FN charge assignments have been proposed, their evaluation has largely relied on heuristic approaches. This paper systematically investigates viable FN charge assignments within the Standard Model, including both the quark and lepton sectors, using Bayesian statistical analysis. The study explores scenarios involving both the seesaw mechanism and dimension-five operators for neutrino mass generation. A comprehensive parameter scan over FN charges reveals a wide range of charge assignments consistent with observed fermion masses and mixing angles. Interestingly, negative FN charges and significant generational differences in charges are found to be viable, contrary to conventional assumptions. The analysis also compares the seesaw mechanism and dimension-five operator scenarios, finding no strong preference between them for optimal charge assignments. Furthermore, predictions for the lightest neutrino mass and effective Majorana mass relevant for neutrinoless double-beta decay are presented, highlighting regions of parameter space accessible to upcoming experiments. Finally, implications for nucleon decay are studied, demonstrating that different FN charge assignments predict significantly different nucleon decay lifetimes and branching ratios, providing a potential experimental probe for FN models.

   hep-phJHEP(2025)·16 citations
8. 08*

   Bolstering up the existence of $P_s(2080)$

   Breno Agatão🇧🇷 · A. Vertel Nieto🇧🇷 · K. P. Khemchandani🇧🇷 · A. Martinez Torres🇧🇷 · Seung-il Nam🇰🇷

   We present a detailed study of the partial decay widths of a spin-parity resonance $J^P=3/2^{-}$ $N^{\ast }$ with a mass of $\simeq$ 2070 MeV obtained from the coupled channel s wave vector-baryon $\rho N$, $\omega N$, $\varphi N$, $K^{\ast }\Lambda$ and $K^{\ast }\Sigma$ dynamics. This state, which couples strongly to the $K^{\ast }\Sigma$ channel, corresponds to a nucleon with a hidden strange quark content, in analogy to the $P_c$ states discovered by the LHCb collaboration, and we denote it as $P_s(2080)$. A state with such a nature can decay to vector-baryon, pseudoscalar-baryon, and pseudoscalar-baryon resonance channels, involving triangular loops in the latter two cases. As we will show, the partial decay widths to pseudoscalar-baryon resonance channels, like $\pi N^{\ast }(1535)$, $\pi N^{\ast }(1650)$, $K\Lambda (1405)$, are comparable to those related to ground state baryons in the final state, like $\pi N$, $\eta N$, $K\Lambda$. In this way, reactions involving such lighter baryon resonances in the final state can be used as an alternative source of information on the properties of a $N^{\ast }$ with hidden strangeness.

   hep-phnucl-thPRD(2025)·0 citations
9. 09*

   Muonium fine structure: theory update, tests of Lorentz violation and experimental prospects

   Philipp Blumer🇨🇭 · Svenja Geissmann🇨🇭 · Arnaldo J. Vargas🇺🇸 · Gianluca Janka🇨🇭 · Ben Ohayon🇮🇱 · Paolo Crivelli🇨🇭

   We review the status of the QED calculations for the muonium $2S_{1/2}-2P_{3/2}$ energy interval and provide the updated theoretical value of $9874.357\pm 0.001\mathrm{MHz}$. Additionally, we present a model for probing Lorentz-violating coefficients within the Standard Model Extension framework using the fine structure measurement in the presence and absence of a weak external magnetic field, enabling novel tests of CPT and Lorentz symmetry. Using Monte Carlo simulations, we estimate that a precision of $\sim 10\mathrm{kHz}$ on the isolated $2S_{1/2},F=1-2P_{3/2},F=1$ transition could be achievable employing Ramsey's separate oscillatory fields (SOF) technique. Collecting the required statics will become feasible with the upcoming High-Intensity Muon Beam (HiMB) at the Paul Scherrer Institute (PSI) in Switzerland. These advancements will enable precise tests of radiative QED corrections and nuclear self-energy contributions, while also providing tests of new physics and sensitivity to unconstrained coefficients for Lorentz violation within the Standard Model Extension framework.

   hep-phphysics.atom-phEur.Phys.J.D(2025)·8 citations
10. 10*

    Composite nature of the $T_{cc}$ state

    Xian-Wei Kang🇨🇳 · Wen-Shuo Ding🇨🇳

    In 2021, LHCb collaboration reported a very narrow state in the $D^0{D}^0{\pi }^{+}$ mass spectrum just below the $D^{\ast +}{D}^0$ mass threshold. We consider the influence of the Castillejo-Dalitz-Dyson (CDD) pole in the scattering amplitude to derive a general treatment for the two-body final state interaction near its threshold. The line shape (or the energy dependent event distribution) are then obtained, where the parameters can be fixed by fitting to the experimental data on the $D^0{D}^0{\pi }^{+}$ mass spectrum. Within our method the data are quite well reproduced. The pole structure in the complex energy plane indicates that the $T_{cc}$ state has a large portion of elementary degree of freedom (e.g., the compact tetraquark component) inside its hadron wave function. The compositeness as a measure of molecule component in its wave function is predicted to be $0.23_{-0.09}^{+0.40}$. Clearly, the non-molecular component takes a non-negligible or even dominant portion.

    hep-phhep-exnucl-thCommun.Theor.Phys.(2025)·1 citation
11. 11*

    Net-Baryon Number Probability Distribution As an Indicator of Phase Transition

    R.N.Rogalyov🇷🇺 · V.A.Goy🇷🇺

    The net-baryon number probability distribution and the related pressure and density are studied in the Cluster Expansion Model (CEM) and the obtained results are extrapolated to the domain of low temperatures. It is found that the rate of decrease of the net-baryon number probability mass function diminishes with the temperature and, in the extensions of the CEM, falls to the level consistent with the phase transition at large baryon chemical potentials.

    hep-phMoscow Univ.Phys.Bull.(2024)·0 citations
12. 12*

    ${\mu }^{-}{\mu }^{+}\to {\nu }_{\mu }{\bar{\nu }}_{\mu }t\bar{t}H$ amplitudes in the Feynman-diagram gauge

    Ya-Juan Zheng🇯🇵

    We study the process ${\mu }^{-}{\mu }^{+}\to {\nu }_{\mu }{\bar{\nu }}_{\mu }t\bar{t}H$ with complex CP violating $ttH$ couplings in the SMEFT with a dimension-6 operator. When the amplitudes are expressed in the Feynman-Diagram gauge, the dominance of the total cross section via the weak boson fusion diagrams is manifest. The high energy behaviour is dictated by the higher-dimensional vertices in the dimension-6 SMEFT operator. These properties are not manifest in the unitary gauge because of subtle cancellation among diagrams.

    hep-phEPJ Web Conf.(2024)·1 citation
13. 13*

    Minimal dark matter in $SU(5)$ grand unification

    Takashi Toma🇯🇵

    Minimal dark matter is an attractive candidate for dark matter because it is stabilized without the need to impose additional symmetries. It is known that the $SU(2{)}_L$ quintuplet fermion can serve as a minimal dark matter candidate, with its mass predicted to be around $14\mathrm{TeV}$, based on the thermal production mechanism. In this work, we embed the quintuplet dark matter within nonsupersymmetric $SU(5)$ grand unified theories. We find that two pairs of colored sextet fermions are required at the $\mathcal{O}(1-10)\mathrm{TeV}$ scale to achieve gauge coupling unification, with the unification scale near the reduced Planck scale. These colored sextet fermions become metastable because their interactions are suppressed by the unification scale. Our model can be tested through comprehensive searches for colored sextet fermions in collider experiments, as well as through indirect and direct detection methods for minimal dark matter. Once the minimal dark matter scenario has been experimentally confirmed, it will have implications for modifying string theories.

    hep-phhep-exhep-thPRD(2025)·1 citation
14. 14*

    DLScanner: A parameter space scanner package assisted by deep learning methods

    A. Hammad🇯🇵 · Raymundo Ramos🇰🇷

    In this paper, we introduce a scanner package enhanced by deep learning (DL) techniques. The proposed package addresses two significant challenges associated with previously developed DL-based methods: slow convergence in high-dimensional scans and the limited generalization of the DL network when mapping random points to the target space. To tackle the first issue, we utilize a similarity learning network that maps sampled points into a representation space. In this space, in-target points are grouped together while out-target points are effectively pushed apart. This approach enhances the scan convergence by refining the representation of sampled points. The second challenge is mitigated by integrating a dynamic sampling strategy. Specifically, we employ a VEGAS mapping to adaptively suggest new points for the DL network while also improving the mapping when more points are collected. Our proposed framework demonstrates substantial gains in both performance and efficiency compared to other scanning methods.

    hep-phcs.CVhep-exhep-thComput.Phys.Commun.(2025)·6 citations
15. 15*

    Nonperturbative effects in triple-differential dijet and Z+jet production at the LHC

    Stefan Gieseke🇩🇪 · Maximilian Horzela🇩🇪 · Manjit Kaur🇮🇳 · Dari Leonardi🇩🇪 · Klaus Rabbertz🇩🇪 · Aayushi Singla🇮🇳 · Cedric Verstege🇩🇪

    In comparisons of precision measurements at colliders to the most accurate predictions available in perturbative quantum chromodynamics (QCD), it is required to correct for nonperturbative effects. By means of Monte Carlo event generators this article investigates the impact of such nonperturbative effects on two processes relevant for precision determinations of the strong coupling constant and the proton structure: triple-differential dijet and Z+jet production. We observe significant differences between the two processes. Whether this non-universal behaviour is realized in nature remains an open question. We therefore propose a triple-differential measurement of the underlying event in Z+jet production.

    hep-phSciPost Phys.(2026)·1 citation
16. 16*

    Schwinger pair production in spacetime fields: Moiré patterns, Aharonov-Bohm phases and Sturm-Liouville eigenvalues

    Gianluca Degli Esposti🇩🇪 · Greger Torgrimsson🇸🇪

    We use a worldline-instanton formalism to study the momentum spectrum of Schwinger pair production in spacetime fields with multiple stationary points. We show that the interference structure changes fundamentally when going from purely time-dependent to space-time-dependent fields. For example, it was known that two time-dependent pulses give interference if they are anti-parallel, i.e. $E_z(t)-E_z(t-\Delta t)$, but here we show that two spacetime pulses will typically give interference if they instead are parallel, i.e. $E_z(t,z)+E_z(t-\Delta t,z-\Delta z)$. We take into account the fact that the momenta of the electron, $p_z$, and of the positron, $p_z^{\prime }$, are independent for $E_z(t,z)$ (it would be $p_z+p_z^{\prime }=0$ for $E(t)$), and find a type of fields which give moiré patterns in the $p_z-p_z^{\prime }$ plane. Depending on the separation of two pulses, we also find an Aharonov-Bohm phase. We also study complex momentum saddle points in order to obtain the integrated probability from the spectrum. Finally, we calculate an asymptotic expansion for the eigenvalues of the Sturm-Liouville equation that corresponds to the saddle-point approximation of the worldline path integral, use that expansion to compute the product of eigenvalues, and compare with the result obtained with the Gelfand-Yaglom method.

    hep-phhep-thPRD(2025)·11 citations
17. 17*

    TooLQit: Leptoquark Models and Limits

    Arvind Bhaskar🇮🇳 · Yash Chaurasia🇮🇳 · Arijit Das🇮🇳 · Atirek Kumar🇮🇳 · Tanumoy Mandal🇮🇳 · Subhadip Mitra🇮🇳 · Cyrin Neeraj🇮🇳 · Rachit Sharma🇮🇳

    We introduce the leptoquark (LQ) toolkit, TooLQit, which includes leading-order FeynRules models for all types of LQs and a Python-based calculator, named CaLQ, to test if a set of parameter points are allowed by the LHC dilepton searches. The models include electroweak gauge interactions of the LQs and follow a set of intuitive notations. Currently, CaLQ can calculate the LHC limits on LQ ($S_1$ and $U_1$) couplings (one or more simultaneously) for any mass between $1$ and $5$ TeV using a ${\chi }^2$ method. In this manual for TooLQit, we describe the FeynRules models and discuss the techniques used in CaLQ. We outline the workflow to check parameter spaces of LQ models with an example. We show some illustrative scans for one- and multi-coupling scenarios for the $U_1$ vector LQ. The TooLQit code is available at https://github.com/rsrchtsm/TooLQit

    hep-ph5 citations
18. 18*

    Hard Photon Triggered Jets in $p$-$p$ and $A$-$A$ Collisions

    C. Sirimanna🇺🇸 · Y. Tachibana🇯🇵 · A. Majumder🇺🇸 · A. Angerami🇺🇸 · R. Arora🇺🇸 · S. A. Bass🇺🇸 · Y. Chen🇺🇸 · R. Datta🇺🇸 · L. Du🇨🇦 · R. Ehlers🇺🇸 · H. Elfner🇩🇪 · R. J. Fries🇺🇸 and 40 other authors

    An investigation of high transverse momentum (high-$p_T$) photon triggered jets in proton-proton ($p$-$p$) and ion-ion ($A$-$A$) collisions at $\sqrt{s_{NN}}=0.2$ and $5.02\mathrm{TeV}$ is carried out, using the multistage description of in-medium jet evolution. Monte Carlo simulations of hard scattering and energy loss in heavy-ion collisions are performed using parameters tuned in a previous study of the nuclear modification factor ($R_{AA}$) for inclusive jets and high-$p_T$ hadrons. We obtain a good reproduction of the experimental data for photon triggered jet $R_{AA}$, as measured by the ATLAS detector, the distribution of the ratio of jet to photon $p_T$ ($X_{\mathrm{J}\gamma }$), measured by both CMS and ATLAS, and the photon-jet azimuthal correlation as measured by CMS. We obtain a moderate description of the photon triggered jet $I_{AA}$, as measured by STAR. A noticeable improvement in the comparison is observed when one goes beyond prompt photons and includes bremsstrahlung and decay photons, revealing their significance in certain kinematic regions, particularly at $X_{J\gamma }>1$. Moreover, azimuthal angle correlations demonstrate a notable impact of non-prompt photons on the distribution, emphasizing their role in accurately describing experimental results. This work highlights the success of the multistage model of jet modification to straightforwardly predict (this set of) photon triggered jet observables. This comparison, along with the role played by non-prompt photons, has important consequences on the inclusion of such observables in a future Bayesian analysis.

    hep-phnucl-exnucl-thPRC(2025)·8 citations
19. 19*

    Right-handed neutrino production through first-generation leptoquarks

    Gokul Duraikandan🇮🇳 · Rishabh Khanna🇮🇳 · Tanumoy Mandal🇮🇳 · Subhadip Mitra🇮🇳 · Rachit Sharma🇮🇳

    The collider phenomenology of leptoquarks (LQs) and right-handed neutrinos (RHNs) has been studied extensively in the literature. Because of the gauge singlet nature, the production of RHNs at the LHC is typically suppressed by the tiny light-heavy neutrino mixing angles. In this study, we explore a promising scenario where the presence of an LQ mediator significantly enhances RHN production. We focus on first-generation scalar and vector LQs interacting with the first-generation RHN. The prospects are better for the first-generation scenario than the other generations because of the enhanced parton distribution functions (PDFs) of first-generation quarks. The enhanced PDFs boost the production cross sections of LQs, particularly their single and indirect productions. Incorporating all production modes of LQs that result in a pair of RHNs, we estimate the discovery prospects by analysing the monoelectron and dielectron channels arising from the decay of the RHN pair. We find that the indirect production of LQs is crucial in determining the discovery reach at the HL-LHC for the first-generation scenario.

    hep-phPRD(2025)·4 citations
20. 20*

    Nonlinear trident using WKB and worldline instantons

    Gianluca Degli Esposti🇩🇪 · Greger Torgrimsson🇸🇪

    We consider nonlinear trident, $e^{-}\to e^{-}{e}^{-}{e}^{+}$, in various electric background fields. This process has so far been studied for plane-wave backgrounds, using Volkov solutions. Here we first use WKB for trident in time-dependent electric fields, and then for fields which vary slowly in space. Then we show how to use worldline instantons for more general fields which depend on both time and space. For time-dependent fields the WKB approach is at least as simple to use as the worldline approach, but already the relatively modest step of including a slow spatial dependence makes the worldline approach much more efficient.

    hep-phhep-thPRD(2025)·4 citations
21. 21*

    Non-Scaling Topological Defects and Gravitational Waves in Higgs Portal

    Wen Yin🇯🇵

    One of the simplest extensions of the Standard Model is the Higgs portal extension involving a dark Higgs. Dark sectors that include dark matter candidates, WIMPs, axions, and dark photons, can naturally have this type of interaction, where the dark Higgs is charged under some symmetry, which may or may not be spontaneous broken by the vacuum expectation value. In this paper, using lattice simulations, I show that if the reheating temperature of the Universe is sufficiently high, topological defects such as domain walls and cosmic strings associated with these symmetries are naturally formed even if the symmetries are never restored due to negative thermal mass squareds. This occurs due to the early Universe's non-adiabatic oscillation of the Higgs around the onset of oscillation, which overshoots the origin, and tachyonic instability that enhances fluctuations. The gravitational waves generated by these topological defects may be very significant due to the energetic processes induced by matter effects in the hot and dense Universe irrelevant to the typical energy scale of the dark sector in the vacuum or whether the symmetry is broken in the vacuum. Alongside earlier studies such as usual phase transition, melting domain walls and melting cosmic strings scenarios that assume a symmetric phase in the early Universe, the Higgs portal models naturally predict local overdensities from topological defects, which may induce miniclusters and primordial black holes, as well as the gravitational waves.These phenomena provide novel opportunities to search for such scenarios. I also perform various numerical simulations for the relevant topic including melting domain walls and cosmic strings with inflationary and Gaussian fluctuations, for comparison--which have not been performed previously.

    hep-phastro-ph.COhep-exhep-latPTEP(2025)·10 citations
22. 22*

    Rational-function interpolation from p-adic evaluations in scattering amplitude calculations

    Herschel A. Chawdhry🇺🇸

    Numerical interpolation techniques are widely employed for calculating large rational functions in scattering amplitude computations. It has been observed in recent years that these rational functions greatly simplify upon partial fractioning. In this conference proceedings paper, based on the article [H. A. Chawdhry, Phys. Rev. D 110, 056028 (2024)], a technique is presented to interpolate such rational functions directly in partial-fractioned form, from evaluations at special integer points chosen for their properties under a p-adic absolute value. It is shown that the technique can require 25 times fewer numerical probes than conventional finite-field-based techniques and can produce results that are more compact in size by 2 orders of magnitude. The reconstructed results moreover exhibit additional patterns that could be exploited in future work to further improve the size of the results and the number of required numerical probes.

    hep-phhep-thphysics.comp-ph0 citations
23. 23*

    Planar Six-Point Feynman Integrals for Four-Dimensional Gauge Theories

    Samuel Abreu🇨🇭 · Pier Francesco Monni🇨🇭 · Ben Page🇧🇪 · Johann Usovitsch🇨🇭

    We compute all planar two-loop six-point Feynman integrals entering scattering observables in massless gauge theories such as QCD. A central result of this paper is the formulation of the differential-equations method under the algebraic constraints stemming from four-dimensional kinematics, which in this case leaves only 8 independent scales. We show that these constraints imply that one must compute topologies with only up to 8 propagators, instead of the expected 9. This leads to the decoupling of entire classes of integrals that do not contribute to scattering amplitudes in four dimensional gauge theories. We construct a pure basis and derive their canonical differential equations, of which we discuss the numerical solution. This work marks an important step towards the calculation of massless $2\to 4$ scattering processes at two loops.

    hep-phhep-thJHEP(2025)·31 citations
24. 24*

    Disentangling axion-like particle couplings to nucleons via a delayed signal in Super-Kamiokande from a future supernova

    David Alonso-González🇪🇸 · David Cerdeño🇪🇸 · Marina Cermeño🇪🇸 · Andres D. Perez🇪🇸

    In this work, we show that, if axion-like particles (ALPs) from core-collapse supernovae (SNe) couple to protons, they would produce very characteristic signatures in neutrino water Cherenkov detectors through their scattering off free protons via $ap\to p\gamma$ interactions. Specifically, sub-MeV ALPs would generate photons with energies $\sim 30$ MeV, which could be observed by Super-Kamiokande and Hyper-Kamiokande as a delayed signal after a future detection of SN neutrinos. We apply this to a hypothetical neighbouring SN (at a maximum distance of 100 kpc) and demonstrate that the region in the parameter space with ALP masses between $10^{-4}$ MeV and $1$ MeV and ALP-proton couplings in the range $3\times 10^{-6}-4\times 10^{-5}$ could be probed. We argue that this new signature, combined with the one expected at $\sim 7$ MeV from oxygen de-excitation, would allow us to disentangle ALP-neutron and ALP-proton couplings.

    hep-phastro-ph.COPRD(2025)·9 citations
25. 25*

    Hydrodynamic Description of the Quark-Gluon Plasma

    Ulrich Heinz🇺🇸 · Björn Schenke🇺🇸

    We review the history and success of applying relativistic hydrodynamics to high-energy heavy-ion collisions. We emphasize the important role hydrodynamics has played in the discovery of the quark-gluon plasma and its quantitative exploration.

    ↳ nucl-thhep-ph38 citations
26. 26*

    QCD Axion Dark Matter in the Dark Dimension

    Hai-Jun Li🇨🇳

    The recently proposed dark dimension scenario reveals that axions can be localized on the Standard Model brane, thereby predicting the quantum chromodynamics (QCD) axion decay constant from the Weak Gravity Conjecture: $f_a\lesssim M_5\sim 10^9-10^{10}\mathrm{GeV}$, where $M_5$ is the five-dimensional Planck mass. When combined with observational lower bounds, this implies that $f_a$ falls within a narrow range $f_a\sim 10^9-10^{10}\mathrm{GeV}$, corresponding to the axion mass $m_a\sim 10^{-3}-10^{-2}\mathrm{eV}$. At this scale, the QCD axion constitutes a minor fraction of the total cold dark matter (DM) density $\sim 10^{-3}-10^{-2}$. In this work, we investigate the issue of QCD axion DM within the context of the dark dimension and demonstrate that the QCD axion in this scenario can account for the entire DM abundance through a simple two-axion mixing mechanism. Specifically, we consider the resonant conversion of an axion-like particle (ALP) into the QCD axion. We find that, in a scenario where the ALP possesses a mass of approximately $m_A\sim 10^{-5}\mathrm{eV}$ and a decay constant of $f_A\sim 10^{11}\mathrm{GeV}$, the QCD axion in the dark dimension can account for the overall DM. The ALP required within this specific range may originate from the grand unification of gauge forces in the dark dimension.

    ↳ hep-thhep-phJHEP(2025)·9 citations
27. 27*

    Oscillons in AdS space

    Takaaki Ishii🇯🇵 · Takaki Matsumoto🇯🇵 · Kanta Nakano🇯🇵 · Ryosuke Suda🇯🇵 · Kentaroh Yoshida🇯🇵

    We study oscillons in a real scalar field theory in a (3+1)-dimensional AdS space with global coordinates. The initial configuration is given by a Gaussian shape with an appropriate core size as in Minkowski spacetime. The solution exhibits a long lifetime. In particular, since the AdS space can be seen as a box, the recurrence phenomenon can be observed under suitable conditions. In particular, as the AdS radius decreases, one can see a transition from a metastable oscillon to a stable oscillatory solution. Finally, we discuss some potential applications of the oscillon in the context of AdS/CFT duality.

    ↳ hep-thhep-phnlin.PSJHEP(2025)·1 citation
28. 28*

    Impact of dineutrons on nuclear compositions of a core-collapse supernova

    Tatsuya Matsuki🇯🇵 · Shun Furusawa🇯🇵 · Katsuhiko Suzuki🇯🇵

    We study the nuclear compositions in the central region of a core-collapse supernova, assuming the existence of dineutrons (${}^{2}n$) and tetraneutrons (${}^{4}n$). At 100~ms after core bounce, ${}^{2}n$ and ${}^{4}n$ are more abundant than deuterons within radii of approximately 100 and 50~km, respectively. Compared to the model ignoring the existence of ${}^{2}n$ and ${}^{4}n$, the mass fraction of neutrons up to a radius of 100~km reduces, while the mass fractions of protons, deuterons, and ${}^4\mathrm{He}$ increase. Due to the uncertainties in the properties of ${}^{2}n$ and ${}^{4}n$, we investigate the influence of their binding energies on the nuclear composition. We find the binding energy of ${}^{2}n$ has only a modest effect on the overall composition, except for its own mass fraction, while that of ${}^{4}n$ has a negligible impact.

    ↳ nucl-thastro-ph.HEastro-ph.SRhep-phPRC(2025)·3 citations
29. 29*

    Stringy scaling of multi-tensor hard string scattering amplitudes and the K-identities

    Sheng-Hong Lai🇹🇼 · Jen-Chi Lee🇹🇼 · Yi Yang🇹🇼

    We calculate n-point hard string scattering amplitudes (HSSA) with n-2 tachyons and 2 tensor states at arbitrary mass levels. We discover the stringy scaling behavior of these HSSA. It is found that for HSSA with more than 2 transverse directions, the degree of stringy scaling dimM2 decreases comparing to the degree of stringy scaling dimM1 of the n-1 tachyons and 1 tensor HSSA calculated previously. Moreover, we propose a set of K-identities which is the key to demonstrate the stringy scaling behavior of HSSA. We explicitly prove both the diagonal and off-diagonal K-identities for the 4-point HSSA and give numerical proofs of these K-identities for some higher point HSSA.

    ↳ hep-thhep-lathep-phmath-ph+1JHEP(2025)·1 citation
30. 30*

    Standardizing reverberation-mapped H$\alpha$ and H$\beta$ active galactic nuclei using radius--luminosity relations involving monochromatic and broad H$\alpha$ luminosities

    Shulei Cao🇺🇸 · Amit Kumar Mandal🇵🇱 · Michal Zajaček🇨🇿 · Bożena Czerny🇵🇱 · Bharat Ratra🇺🇸

    We test the standardizability of a homogeneous sample of 41 lower-redshift ($0.00415\le z\le 0.474$) active galactic nuclei (AGNs) reverberation-mapped (RM) using the broad H$\alpha$ and H$\beta$ emission lines. We find that these sources can be standardized using four radius$-$luminosity ($R-L$) relations incorporating H$\alpha$ and H$\beta$ time delays and monochromatic and broad H$\alpha$ luminosities. Although the $R-L$ relation parameters are well constrained and independent of the six cosmological models considered, the resulting cosmological constraints are weak. The measured $R-L$ relations exhibit slightly steeper slopes than predicted by a simple photoionization model and steeper than those from previous higher-redshift H$\beta$ analyses based on larger datasets. These differences likely reflect the absence of high-accreting sources in our smaller, lower-redshift sample, which primarily comprises lower-accreting AGNs. The inferred cosmological parameters are consistent within 2$\sigma$ (or better) with those from better-established cosmological probes. This contrasts with our earlier findings using a larger, heterogeneous sample of 118 H$\beta$ AGNs, which yielded cosmological constraints differing by $\gtrsim 2\sigma$ from better-established cosmological probes. Our analysis demonstrates that sample homogeneity$-$specifically, the use of a consistent time-lag determination method$-$is crucial for developing RM AGNs as a cosmological probe.

    ↳ astro-ph.GAastro-ph.COgr-qchep-ph+1PRD(2025)·7 citations
31. 31*

    Flavor Physics at the CEPC: a General Perspective

    Xiaocong Ai · Wolfgang Altmannshofer · Peter Athron · Xiaozhi Bai · Lorenzo Calibbi · Lu Cao · Yuzhi Che · Chunhui Chen · Ji-Yuan Chen · Long Chen · Mingshui Chen · Shanzhen Chen and 139 other authors

    We discuss the landscape of flavor physics at the Circular Electron-Positron Collider (CEPC), based on the nominal luminosity outlined in its Technical Design Report. The CEPC is designed to operate in multiple modes to address a variety of tasks. At the $Z$ pole, the expected production of 4 Tera $Z$ bosons will provide unique and highly precise measurements of $Z$ boson couplings, while the substantial number of boosted heavy-flavored quarks and leptons produced in clean $Z$ decays will facilitate investigations into their flavor physics with unprecedented precision. We investigate the prospects of measuring various physics benchmarks and discuss their implications for particle theories and phenomenological models. Our studies indicate that, with its highlighted advantages and anticipated excellent detector performance, the CEPC can explore beauty and $\tau$ physics in ways that are superior to or complementary with the Belle II and Large-Hadron-Collider-beauty experiments, potentially enabling the detection of new physics at energy scales of 10 TeV and above. This potential also extends to the observation of yet-to-be-discovered rare and exotic processes, as well as testing fundamental principles such as lepton flavor universality, lepton and baryon number conservation, etc., making the CEPC a vibrant platform for flavor physics research. The $WW$ threshold scan, Higgs-factory operation and top-pair productions of the CEPC further enhance its merits in this regard, especially for measuring the Cabibbo-Kobayashi-Maskawa matrix elements, and Flavor-Changing-Neutral-Current physics of Higgs boson and top quarks. We outline the requirements for detector performance and considerations for future development to achieve the anticipated scientific goals.

    ↳ hep-exhep-phCPC(2025)·53 citations
32. 32*

    Cosmohedra

    Nima Arkani-Hamed🇺🇸 · Carolina Figueiredo🇺🇸 · Francisco Vazão🇩🇪

    It has been a long-standing challenge to find a geometric object underlying the cosmological wavefunction for Tr(${\varphi }^3$) theory, generalizing associahedra and surfacehedra for scattering amplitudes. In this note we describe a new class of polytopes -- "cosmohedra" -- that provide a natural solution to this problem. Cosmohedra are intimately related to associahedra, obtained by "blowing up" faces of the associahedron in a simple way, and we provide an explicit realization in terms of facet inequalities that further "shave" the facet inequalities of the associahedron. We also discuss a novel way for computing the wavefunction from cosmohedron geometry that extends the usual connection with polytope canonical forms. We illustrate cosmohedra with examples at tree-level and one loop; the close connection to surfacehedra suggests the generalization to all loop orders. We also briefly describe "cosmological correlahedra" for full correlators. We speculate on how the existence of cosmohedra might suggest a "stringy" formulation for the cosmological wavefunction/correlators, generalizing the way in which the Minkowski sum decomposition of associahedra naturally extend particle to string amplitudes.

    ↳ hep-thastro-ph.COgr-qchep-phJHEP(2025)·60 citations
33. 33*

    Stellar Physics and General Relativity

    Shuichi Yokoyama🇯🇵

    The general theory of relativity is currently established as the most precise theory of gravity supported by observations, and its application is diverse ranging from astronomy to cosmology, while its application to astrophysics has been restricted only to compact stars due to the assumption that the Newtonian approximation is sufficient for celestial bodies with medium density such as the sun. Surprisingly, the recent research of the author has implied that this long-held assumption is not valid, and that non-perturbative effects significantly change relevant results obtained by Newtonian gravity. In particular, local physical quantities inside the sun are newly predicted to exhibit power law differently from the so-called standard solar model. This surprising result is reviewed including brief discussion of physics behind the discrepancy and a new application of the new mass formula to gas planets.

    ↳ astro-ph.SRastro-ph.EPgr-qchep-ph+1Astron.Nachr.(2025)·1 citation

* 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.