Wed·Jun 25, 2025Wednesday·June 25, 2025

1. 01*

   Charmed baryon decays: $SU(3{)}_F$ breaking and CP violation

   Chang Yang🇨🇳 · Xiao-Gang He🇨🇳 · Chia-Wei Liu🇨🇳

   We present a comprehensive study of anti-triplet charmed baryon decays into octet baryons and pseudoscalar mesons using the $SU(3{)}_F$ flavor symmetry framework. By decomposing the flavor structure, all decay amplitudes are parametrized with a minimal set of irreducible amplitudes, and the Körner-Pati-Woo theorem further reduces the number of independent parameters from the original 35 to 19 under exact symmetry when small terms proportional to ${\lambda }_b=V_{cb}^{\ast }{V}_{ub}$ are neglected. The independent number becomes 27 with leading $SU(3{)}_F$ breaking effects. A global fit to 51 experimental measurements yields a ${\chi }^2$/d.o.f. of 2.36 and provides precise values for the decay amplitudes. Notable discrepancies are observed in the fitted branching fractions of ${\Xi }_c^0\to {\Xi }^{-}{\pi }^{+}$ and ${\Xi }_c^{+}\to {\Xi }^{-}{\pi }^{+}{\pi }^{+}$, which exceed current measurements by more than $2\sigma$. Incorporating final-state rescattering effects to recover the main effects of terms proportional to ${\lambda }_b$, we predict enhanced CP violation, with $A_{CP}$ reaching up to $10^{-3}$ in golden channels such as ${\Xi }_c^0\to p{K}^{-}$ and ${\Xi }_c^0\to {\Sigma }^{+}{\pi }^{-}$. Our analysis also finds that the branching ratio for ${\Xi }_c^{+}\to \Lambda {\pi }^{+}$ is enhanced to $(9.7\pm 1.2)\times 10^{-4}$ due to significant cancellations.

   hep-phhep-exJHEP(2025)·8 citations
2. 02*

   WIMPs Below the Radar: Blind Spots and Benchmarks Beyond the Neutrino Floor

   Giorgio Arcadi🇮🇹 · Stefano Profumo🇺🇸

   We investigate benchmark scenarios for Weakly Interacting Massive Particles (WIMPs) that naturally evade current direct detection constraints by featuring suppressed spin-independent cross-sections. Focusing on three representative models, the Singlet-Doublet fermion model, its extension to a Two-Higgs-Doublet plus pseudoscalar sector (2HDM$+a$), and a dark $SU(3)$ gauge model, we systematically analyze the interplay between thermal freeze-out, direct detection blind spots, and radiative corrections. In each case, we identify viable regions of parameter space where the predicted dark matter relic abundance is consistent with observations while elastic scattering rates lie below current exclusion limits and, in some cases, but now always, below the neutrino floor. Loop-induced effects are shown to play a critical role, particularly in scenarios with suppressed tree-level interactions. Our findings demonstrate that models with rich electroweak and scalar sectors can populate the experimentally challenging, yet phenomenologically motivated parameter space between existing constraints and the ultimate sensitivity of current-technology direct detection experiments.

   hep-phJHEP(2025)·6 citations
3. 03*

   Interferometry Radii at RHIC BES Energies within the integrated HydroKinetic Model

   Vladislav Naboka🇺🇦 · Yuri Sinyukov🇵🇱 · Musfer Adzhymambetov🇺🇦 · Hanna Zbroszczyk🇵🇱

   The work is devoted to research of pion femtoscopic correlations in relativistic heavy-ion collisions across the RHIC Beam Energy Scan range using the extended integrated HydroKinetic Model (iHKMe). The model provides a comprehensive description of the system's dynamical evolution, starting from the initial collision state of colliding nuclei, passing through a possible thermalization process and hydrodynamic expansion to the hadron interacting cascade and formation of the observed particle spectra. The model smoothly couples all these stages of the matter evolution, ensuring a smooth transition between the stages. A primary focus of the current work, in contrast to the similar investigation within iHKM for high energies, concentrated in the energy region where extended nuclear overlap times and incomplete thermalization significantly influence the system's expansion comparing with very high energies. We extract the three-dimensional interferometry radii ($R_{out}$, $R_{side}$, $R_{long}$) in the region from 7.7 to 39 GeV per nucleon pair and evaluate their sensitivity to the features of the equation of state (EoS), specifically comparing crossover and first-order phase transition scenarios. The model demonstrates good agreement with experimental measurements in the crossover case. As for the first-order phase transition scenario, the $R_{long}$ component, at the optimal model parameters for particle spectra, is noticeably higher than the experimental data, and the difference is more pronounced with the growth of collision energy. Such a behavior is caused by the increased system's lifetime during the mixed-phase stage. The corresponding analysis within iHKMe below $\sqrt{s_{NN}}=7.7$ GeV will be presented within a separate investigation.

   hep-phnucl-th0 citations
4. 04*

   Quantum vs. semiclassical description of in-QGP quarkonia in the quantum Brownian regime

   Aoumeur Daddi-Hammou🇫🇷 · Stéphane Delorme🇵🇱 · Jean-Paul Blaizot🇫🇷 · Pol Bernard Gossiaux🇫🇷 · Thierry Gousset🇫🇷

   In this work, we explore the range of validity of the semiclassical approximation of a quantum master equation designed to describe the $c\bar{c}$ dynamics in a quark gluon plasma at various temperatures, in the quantum Brownian regime. We perform a comparative study of various properties, e.g. the charmonia yield, of the Wigner density obtained with the Lindblad equation and with the associated semiclassical Fokker-Planck equation. The semiclassical description is found to reproduce with a remarkable accuracy the results obtained through the full quantum description. We show that, to a large extent, this can be attributed to the non-unitary components of the dynamics that result from the contact of the $c\bar{c}$ subsystem with the thermal bath, leading to a rapid classicalization of the subsystem.

   hep-phhep-thquant-phPRD(2026)·6 citations
5. 05*

   Relativistic corrections to hadron-hadron correlation function

   Zeyu Zeng🇨🇳 · Baoyi Chen🇨🇳 · Jiaxing Zhao🇩🇪

   Femtoscopy offers a sensitive probe of hadron emission sources and hadronic interactions. In this study, we examine relativistic corrections to scattering phase shifts and correlation functions using the two-body Dirac equation framework. We analyze the impact of the Darwin term and spin-dependent potentials, showing that these relativistic effects, especially spin-related interactions, significantly enhance the proton-proton correlation function. Our findings emphasize the necessity of including relativistic corrections for precise femtoscopic analyses.

   hep-phnucl-thCPC(2026)·2 citations
6. 06*

   Kaon structure modifications in strange hadronic matter

   Manpreet Kaur🇮🇳 · Abi Jebarson A🇮🇳 · Dhananjay Singh🇮🇳 · Navpreet Kaur🇮🇳 · Suneel Dutt🇮🇳 · Harleen Dahiya🇮🇳 · Arvind Kumar🇮🇳

   We present the valence quark distributions of the kaons in an isospin asymmetric dense strange medium consisting of nucleons and hyperons. The comparative analysis of in-medium parton distribution functions, electromagnetic form factors, and charge densities with respect to the free space distributions is studied in the light-cone quark model. The medium effects are incorporated in these distribution functions by using the effective quark masses, computed from the chiral SU(3) quark mean field model for finite values of baryonic density, isospin asymmetry, and strangeness fraction parameters. We observe a suppression of the kaon electromagnetic form factors and a redistribution of charge density in high-density strange matter.

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

   Torsional modulation of atmospheric neutrino oscillation

   Riya Barick🇮🇳 · Amitabha Lahiri🇮🇳

   Fermions act as sources of spacetime torsion. However, this torsion is non-dynamical and can be eliminated using its equations of motion. The resulting theory features an effective four-fermion interaction in a torsion-free background. Generically this interaction is non-universal and violates parity. When neutrinos propagate through matter, they experience the effect of this geometrical interaction, which is similar to the MSW effect, but diagonal in the mass basis. Since this quartic interaction term varies linearly with matter density, its effect will be more prominent for atmospheric neutrinos specially for upward going atmospheric neutrinos. We investigate the effect of spacetime geometry on ${\nu }_{\mu }\to {\nu }_{\tau }$ and ${\nu }_{\mu }\to {\nu }_e$ conversion probability and ${\nu }_{\mu }$ survival probability, by solving the Schrödinger equation using the {Preliminary Reference Earth Model (PREM)} density profile of the Earth. We also study the dependence of atmospheric neutrino oscillation probability on the CP phase angle in presence of this effect. We further provide a discussion of the MSW and parametric resonances in presence of the geometrical interaction.

   hep-phJHEP(2025)·2 citations
8. 08*

   Assessing the accuracy of the GENIE event generator with electron scattering data: Reduced cross section and nuclear transparency

   A. V. Butkevich🇷🇺 · S. V. Luchuk🇷🇺

   The reduced cross sections of the semi-exclusive $(l,l^{\prime }p)$ lepton scattering process can be identified with distorted nuclear spectral functions. Irrespective of the type of interaction the distorted spectral function is determined mainly by intrinsic properties of the target and the ejected nucleon interaction with residual nucleus. Thus the reduced cross sections of the neutrino and electron scattering on nuclei as functions of nucleon missing momentum and energy are similar up to Coulomb corrections. Here we demonstrate the utility of this approach by benchmarking the GENIE neutrino event generator against a broad set of semi-exclusive electron scattering data for carbon target. We observe persistent disagreements between the generator predictions and data in the range of nucleon missing momenta less than 80 MeV/c. The approach presented in this paper provide a great opportunity to test better the accuracy of nuclear models of quasi-elastic neutrino-nucleus scattering, employed in neutrino event generators.

   hep-phhep-thPRD(2025)·4 citations
9. 09*

   Harnessing Higgs Kinematics for HEFT Constraints

   Christoph Englert🇬🇧 · Tom Ingebretsen Carlson🇸🇪 · Jörgen Sjölin🇸🇪 · Michael Spannowsky🇬🇧

   We present a momentum-dependent reweighting strategy to extend current LHC di-Higgs analyses within the $\kappa$-framework and SMEFT into the bosonic sector of the Higgs Effective Field Theory (HEFT). Unlike SMEFT, where symmetry constraints tightly correlate multi-Higgs processes, HEFT allows for a broader range of momentum-dependent deviations that can substantially impact di-Higgs kinematics and offer a powerful probe of non-linear Higgs dynamics. We generalise the interpretation of existing experimental analyses by integrating HEFT operators up to chiral dimension four into differential Monte Carlo reweighting. We quantify the sensitivity to representative HEFT operators using multi-dimensional likelihoods for Run 3 and project the reach at the High-Luminosity LHC (HL-LHC). Particular emphasis is placed on how different exclusive final states, such as $b\bar{b}b\bar{b}$ and $b\bar{b}\gamma \gamma$, respond to momentum enhancements and how their complementary event selections drive exclusion limits. We further explore how rare final states, especially four-top production, can provide orthogonal constraints on HEFT-induced modifications, thereby enhancing global sensitivity to new physics effects in the Higgs sector.

   hep-phhep-exPRD(2025)·3 citations
10. 10*

    Multi-boson splashes at future colliders from electroweak compositeness

    G. Cacciapaglia🇫🇷 · A. Deandrea🇫🇷 · A.M. Iyer🇮🇳 · S. Kulkarni🇦🇹 · A.K Singh🇮🇳

    We propose a new collider signature for the composite origin of the electroweak symmetry breaking of the standard model. The Higgs sector consists of new fundamental fermions (hyper-quarks), which confine at a hadronization scale ${\Lambda }_{HC}\sim$ few TeV. At energies above ${\Lambda }_{HC}$, the Drell-Yan production of the hyper-quarks leads to the production of a few electroweak bosons, in analogy with hadron production in QCD at $e^{+}{e}^{-}\to q\bar{q}$ around a few GeV. We show that this regime can be probed at future colliders, namely the proposed 100 TeV hadron collider (FCC-hh) and a 10 TeV muon collider. Together with the direct discovery of electroweak resonances, the multi electroweak boson signature provides a smoking gun for Higgs compositeness.

    hep-phPRD(2025)·0 citations
11. 11*

    B0 -> K*0 tau+ tau- Decay: Using Machine Learning to Separate Signal from Background

    Ziyao Xiong🇨🇳 · Qixing Deng🇨🇳 · Yidan Sun🇺🇸 · Junhua Yang🇨🇳

    This study investigates the rare decay B0 -> K*0 tau+ tau-, which is sensitive to potential violations of lepton flavor universality predicted by the Standard Model. A Monte Carlo simulated dataset containing both signal and the dominant background process B0 -> K*0 D+ D- was used to train and evaluate machine learning classifiers. After feature selection and parameter tuning, two supervised models -- Boosted Decision Trees (BDTs) and Fully Connected Neural Networks (FCNNs) -- were trained. Feature engineering was then applied to enhance classification performance. On the test set, the BDT achieved an AUC of 0.912 +/- 0.000 and an F1-score of 0.828 +/- 0.001, while the FCNN reached an AUC of 0.877 +/- 0.000 and an F1-score of 0.799 +/- 0.001. These results demonstrate that both models can robustly separate signal from background in rare decay searches, supporting their application in future LHCb analyses.

    hep-ph0 citations
12. 12*

    Mass spectra of doubly heavy baryons in the relativized quark model with heavy-quark dominance

    Zhen-Yu Li🇨🇳 · Guo-Liang Yu🇨🇳 · Zhi-Gang Wang🇨🇳 · Jian-Zhong Gu🇨🇳 · Hong-Tao Shen🇨🇳

    In the framework of the relativized quark model, the mass spectra of the doubly heavy baryons are rigorously calculated in the three-quark system under the heavy-quark dominance mechanism, by using the Gaussian expansion method and the infinitesimally-shifted Gaussian basis functions. With the obtained mass spectra of all doubly heavy baryon families, the contribution of each Hamiltonian term to the energy levels is analyzed. It is found that the spin splitting is mainly determined by the spin-dependent interactions associated with the light quark. Moreover, it is shown that the spin splitting evolves regularly with the mass of heavy quarks by the evolution of the spectral structure, which is consistent with the heavy quark symmetry. Meanwhile, the orbital excitation is dominated by the $\rho$-mode, which is different from that of the singly heavy baryons. At last, our analysis indicates that the ${\Xi }_{cc}^{+}(3520)$ state should not exist truly and the ${\Xi }_{cc}^{++}(3621)$ should be the true ground state with $J^P$ = ${\frac{1}{2}}^{+}$. It is recommended to design the corresponding experiments to search for the ${\Xi }_{cc}^{\ast }$ in the energy range from 3694 to 3714 MeV.

    hep-phEPJC(2025)·2 citations
13. 13*

    Probing the electromagnetic dipole moment of the $\tau$ lepton in the $e^{+}{e}^{-}\to {\gamma }^{\ast }/Z\to {\tau }^{+}{\tau }^{-}$ reaction

    Peng-Cheng Lu🇨🇳 · Zong-Guo Si🇨🇳 · Han Zhang🇨🇳

    High-precision measurements of the lepton's electromagnetic dipole moments provide a powerful probe for testing the Standard Model. A non-zero value of the $\tau$ lepton's electric(weak) dipole moment ($d_{\tau }^{\gamma }$, $d_{\tau }^Z$) would serve as a smoking gun of the new physics. On the one hand, current and future high energy colliders offer an ideal environment for such measurements. On the other hand, it is essential to investigate the optimal measurement method for extracting not only $d_{\tau }^{\gamma }$ and $d_{\tau }^Z$, but also the anomalous magnetic dipole moment ($a_{\tau }$). In this work, we analyze the precision of observables, particularly optimal observables, for determining these physics quantities through the process $e^{+}{e}^{-}\to {\gamma }^{\ast }/Z\to {\tau }^{+}{\tau }^{-}$ with $\tau$ leptons undergoing (semi-)leptonic and hadronic decays at the centre-of-mass energies at the Z pole mass and significantly below $m_Z$. By considering the full kinematic information of the decay products, we find that the sensitivities to Im$d_{\tau }$ and Re$d_{\tau }$ can reach $10^{-21}$ $ecm$ at CEPC $\sqrt{s}=m_Z$, compared to $10^{-20}$ $ecm$ at Belle-II ${\rm Y}(4S)$ resonance and $10^{-17}$ $ecm$ at BEPCII $\psi (2S)$ resonance. For $a_{\tau }$, we find that Im$a_{\tau }$ and Re$a_{\tau }$ with a precision of $10^{-5}$ at Belle-II $\sqrt{s}=10.58$ GeV can be attained.

    hep-phPRD(2025)·5 citations
14. 14*

    Dalitz Plot Kinematics for a Lorentz-Violating Three-Body Decay

    Joshua O'Connor · Brett Altschul

    Rates for particle interaction processes and decays will be modified in a Lorentz-violating quantum field theory, because of changes to the particle kinematics$-$particularly through the modified dispersion relations affecting the outgoing particle phase space. We outline here these changes to the rates for three-particle decays. Considering a process with a constant scattering amplitude (not directly modified by the Lorentz violation), we calculate leading order corrections to the kinematics for a decay into three identical spinless particles whose propagation is affected by a $c_{\mu \nu }$-type symmetric tensor background. We examine the angular distribution of the daughter particles and describe the shape of the corresponding Dalitz plot outlining the kinematically allowed region, according to two toy models for the $c_{\mu \nu }$ textures. Precision measurements of the boundaries of this region could be used to constrain Lorentz violation coefficients for the particles involved in processes such as $\eta \to 3{\pi }^0$.

    hep-phhep-thPhys. Rev. D 112, 075047 (2025)
15. 15*

    Directional search for light dark matter with quantum sensors

    Hajime Fukuda🇯🇵 · Yuichiro Matsuzaki🇯🇵 · Thanaporn Sichanugrist🇯🇵

    The presence of dark matter (DM) stands as one of the most compelling indications of new physics in particle physics. Typically, the detection of wave-like DM involves quantum sensors, such as qubits or cavities. The phase of the sensors is usually discarded as the value of the phase itself is not physically meaningful. However, the difference of the phase between the sensors contains the information of the velocity and direction of the DM wind. We propose a measurement protocol to extract this information from the sensors using quantum states. Our method does not require specific experimental setups and can be applied to any type of DM detector as long as the data from the detectors can be taken quantum mechanically. We also show that our method does not spoil the sensitivity of the DM detectors and is superior to the classical method based on the correlations of the DM signals between the detectors.

    hep-phhep-exquant-phPRL(2025)·15 citations
16. 16*

    Solving the QCD effective kinetic theory with neural networks

    Sergio Barrera Cabodevila🇪🇸 · Aleksi Kurkela🇳🇴 · Florian Lindenbauer🇦🇹

    Event-by-event QCD kinetic theory simulations are hindered by the large numerical cost of evaluating the high-dimensional collision integral in the Boltzmann equation. In this work, we show that a neural network can be used to obtain an accurate estimate of the collision integral in a fraction of the time required for the ordinary Monte Carlo evaluation of the integral. We demonstrate that for isotropic and anisotropic distribution functions, the network accurately predicts the time evolution of the distribution function, which we verify by performing traditional evaluations of the collision integral and comparing several moments of the distribution function. This work sets the stage for an event-by-event modeling of the pre-equilibrium initial stages in heavy-ion collisions.

    hep-phnucl-thEPJC(2025)·9 citations
17. 17*

    Cross-sections and experimental signatures for detection of a well-defined dark matter WIMP

    Bailey Tallman🇺🇸 · Jehu Martinez🇺🇸 · Rohan Shankar🇮🇹 · Kane Rylander🇺🇸 · Roland E. Allen🇺🇸

    We report the following calculations for a recently proposed bosonic dark matter WIMP with well-defined interactions: (1)~the mass as determined by fitting to the relic abundance; (2)~the current annihilation cross-section for indirect detection; (3)~cross-sections for pair production accompanied by jets in proton colliders with center-of-mass energies ranging from 13 to 100 TeV; (4)~for the high-luminosity LHC, and planned 100 TeV proton collider, detailed plots of experimentally accessible quantities before and after optimal cuts; (5)~cross-sections, and plots of experimentally accessible quantities, for production in e${}^{+}$e${}^{-}$ or muon colliders with center-of-mass energies up to 10 TeV; (6)~cross-section per nucleon for direct detection. The conclusions are given in the text, including the principal prediction that (with optimal cuts) this particle should be detectable at the high-luminosity LHC, perhaps after only two years with an integrated luminosity of 500 fb${}^{-1}$.

    hep-phEPL(2025)·1 citation
18. 18*

    Non-holomorphic modular flavor symmetry and odd weight polyharmonic Maaß form

    Bu-Yao Qu🇨🇳 · Jun-Nan Lu🇨🇳 · Gui-Jun Ding🇨🇳

    We extend the framework of non-holomorphic modular flavor symmetry to include the odd weight polyharmonic Maaß forms. The integer weight polyharmonic Maaß forms of level $N$ can be arranged into multipltets of the homogeneous finite modular group ${\Gamma }_N^{\prime }$. We propose to construct the integer weight, including weight one, non-holomorphic polyharmonic Maaß forms from the non-holomorphic Eisenstein series. The previous results of even weight polyharmonic Maaß forms are reproduced. We apply this formalism to address the flavor structure of the standard model. An example lepton model based on the modular group ${\Gamma }_3^{\prime }\cong T^{\prime }$ is constructed, where neutrino masses are generated via type-I seesaw mechanism with two right-handed neutrinos. This model can accommodate the experimental data for both normal and inverted neutrino mass orderings. We further extend this model to include quarks, so that the masses and mixing parameters of both quark and lepton sectors can be successfully described in terms of only thirteen real free parameters. It is the modular invariant model with the smallest number of free parameters so far, only normal ordering neutrino mass is viable after including quarks, and the correlations among the input parameters and flavor observables are analyzed.

    hep-phJHEP(2025)·15 citations
19. 19*

    IBIS: Inverse BInomial sum Solver

    Paul A.J.W. van Hoegaerden🇳🇱 · Coenraad B. Marinissen🇳🇱 · Wouter J. Waalewijn🇳🇱

    In higher-loop calculations, Mellin-Barnes representations are used to simplify the denominators encountered in Feynman parameter integrals. The contour integrals of these representations yield sums over residues. We develop an efficient method for certain classes of sums involving inverse binomials. Our results are expressed in terms of so-called S-sums, where the dependence on the upper limit of the sum is analytic. This is accomplished by deriving several new recursion relations, obtained from telescoping series and repeated synchronization. We make our results available through IBIS ("Inverse BInomial sum Solver"), a FORM program to perform such inverse binomial sums. To highlight the efficiency of our code: sums up to weight 6 can be carried out in less than a second, and a comparison to the general-purpose SIGMA and EvaluateMultiSums packages is included. We show in examples how inverse binomial sums arise, though some instances are beyond the cases studied here. Our work thus provides a starting point for studying such sums and may open up new avenues in higher-loop calculations.

    hep-ph2 citations
20. 20*

    First High-Throughput Evaluation of Dark Matter Detector Materials

    Sinéad M. Griffin🇺🇸 · Yonit Hochberg🇮🇱 · Benjamin V. Lehmann🇺🇸 · Rotem Ovadia🇮🇱 · Kristin A. Persson🇺🇸 · Bethany A. Suter🇺🇸 · Ruo Xi Yang🇺🇸 · Wayne Zhao🇺🇸

    We perform the first high-throughput search and evaluation of materials that can serve as excellent low-mass dark matter detectors. Using properties of close to one thousand materials from the Materials Project database, we project the sensitivity in dark matter parameter space for experiments constructed from each material, including both absorption and scattering processes between dark matter and electrons. Using the anisotropic materials in the dataset, we further compute the level of daily modulation in interaction rates and the resulting directional sensitivities, highlighting materials with prospects to detect the dark matter wind. Our methods provide the basic tools for the data-driven design of dark matter detectors, and our findings lay the groundwork for the next generation of highly optimized direct searches for dark matter as light as the keV scale.

    hep-phcond-mat.mtrl-scihep-exphysics.ins-detPRL(2026)·6 citations
21. 21*

    Leading bounds on micro- to picometer fifth forces from neutron star cooling

    Damiano F. G. Fiorillo🇩🇪 · Alessandro Lella🇮🇹 · Ciaran A. J. O'Hare🇦🇺 · Edoardo Vitagliano🇮🇹

    The equivalence principle and the inverse-square law of gravity could be violated at short distances ($10^{-6}$ to $10^{-12}$ meters) by scalars sporting a coupling $g_N$ to nucleons and mass $\mathrm{eV}\lesssim m_{\varphi }\lesssim \mathrm{MeV}$. We show for the first time that stringent bounds on the existence of these scalars can be derived from the observed cooling of nearby isolated neutron stars (NSs). Although NSs can only be used to set limits comparable to the classic SN 1987A cooling bound in the case of pseudoscalars such as the QCD axion, the shallow temperature dependence of the scalar emissivity results in a huge enhancement in the effect of $\varphi$ on the cooling of cold NSs. As we do not find evidence of exotic energy losses, we can exclude couplings down to $g_N\lesssim 5\times 10^{-14}$. Our new bound supersedes all existing limits on scalars across six orders of magnitude in $m_{\varphi }$. These conclusions also extend to Higgs-portal models, for which the bound on the scalar-Higgs mixing angle is $\sin \theta \lesssim 6\times 10^{-11}$.

    hep-phastro-ph.HEhep-thPRL(2025)·36 citations
22. 22*

    Road through Dark$\nu$ess: Probing dark matter-neutrino interactions using KM3-230213A

    Ranjini Mondol🇮🇳 · Subhadip Bouri🇮🇳 · Akash Kumar Saha🇮🇳 · Ranjan Laha🇮🇳

    KM3NeT has recently reported an event where a muon of energy $120_{-60}^{+110}$ PeV was observed at its ARCA detector, which can stem from a very high-energy neutrino interaction in the vicinity of the detector. Besides revolutionizing our understanding of high-energy neutrino sources, this event can serve as a valuable probe for studying Beyond the Standard Model (BSM) interactions of neutrinos. In this work, we study the dark matter (DM)-neutrino interaction by assuming the neutrino for the event KM3-230213A is originated from a blazar. The flux of such neutrinos, traveling through DM distributed across astrophysical and cosmological scales, can get attenuated due to DM interactions. The detection of such event by KM3NeT allows us to place constraints on the interaction cross section at highest-ever neutrino energy. We derive both conservative constraints-neglecting flux attenuation from the host halo-and optimistic ones by including host halo contributions. Our results show that the energy-independent constraints are weaker than previous bounds. For energy-dependent case, the extreme energy of the event allows us to set some of the strongest limits on scattering cross sections. In future, more such neutrino events with well-understood origin will be essential in constraining or potentially discovering DM-neutrino interactions.

    hep-phastro-ph.COastro-ph.GAastro-ph.HE+114 citations
23. 23*

    QCD Axion Domain Walls from Super-Cooling First Order Phase Transition

    Kun-Feng Lyu🇺🇸 · Yue Zhao🇺🇸

    The QCD axion is a well-motivated hypothetical particle beyond the Standard Model (SM) and a compelling dark matter candidate. Its relic abundance is highly sensitive to the thermal history of the universe when the temperature is around the QCD confinement scale. Meanwhile, the NANOGrav Collaboration has reported evidence for a stochastic gravitational wave background, which could originate from a supercooled first-order phase transition (FOPT) with a nucleation temperature around the O(MeV-GeV) scale. We explore how such an FOPT might alter the evolution of the QCD axion. Our findings suggest that it could induce the axion to go through a short stage of mini kinetic misalignment. Moreover, in some parameter regime, the formation of QCD axion domain walls becomes generically expected. This has intriguing implications for both the existence of the QCD axion and the FOPT interpretation of the NANOGrav signal.

    hep-phastro-ph.CO3 citations
24. 24*

    Graph theory inspired anomaly detection at the LHC

    Jack Y. Araz🇬🇧 · Dimitrios Athanasakos🇺🇸 · Mateusz Ploskon🇺🇸 · Felix Ringer🇺🇸

    Designing model-independent anomaly detection algorithms for analyzing LHC data remains a central challenge in the search for new physics, due to the high dimensionality of collider events. In this work, we develop a graph autoencoder as an unsupervised, model-agnostic tool for anomaly detection, using the LHC Olympics dataset as a benchmark. By representing jet constituents as a graph, we introduce a method to systematically control the information available to the model through sparse graph constructions that serve as physically motivated inductive biases. Specifically, (1) we construct graph autoencoders based on locally rigid Laman graphs and globally rigid unique graphs, and (2) we explore the clustering of jet constituents into subjets to interpolate between high- and low-level input representations. We obtain the best performance, measured in terms of the Significance Improvement Characteristic curve for an intermediate level of subjet clustering and certain sparse unique graph constructions. We further investigate the role of graph connectivity in jet classification tasks. Our results demonstrate the potential of leveraging graph-theoretic insights to refine and increase the interpretability of machine learning tools for collider experiments.

    hep-phhep-exphysics.data-anJHEP(2026)·4 citations
25. 25*

    Probing jet-medium interactions via jet substructure observables in relativistic heavy-ion collisions

    Xiang-Pan Duan🇨🇳 · Tan Luo🇨🇳 · Guo-Liang Ma🇨🇳

    We present a comprehensive study of jet substructure observables in $pp$ and PbPb collisions at $\sqrt{s_{NN}}=5.02$~TeV using a multi-phase transport model. To suppress background contamination, the constituent subtraction method is employed for both PbPb and smeared $pp$ events. The jet splitting momentum fraction ($z_g$) and the groomed jet mass to the ungroomed jet transverse momentum ($M_g/p_{T,\text{jet}}$) are reconstructed using the Soft Drop algorithm with two grooming parameter settings. With $z_{\text{cut}}=0.1$ and $\beta =0.0$, a slight modification in the $z_g$ distribution is observed in central PbPb collisions, whereas a pronounced enhancement in the high $M_g/p_{T,\text{jet}}$ region is found, particularly at low $p_{T,\text{jet}}$ and in more central events. A detailed analysis of the dynamical evolution stages reveals that this enhancement primarily originates from jet-medium interactions, whereas the contributions from hadronization and hadronic rescatterings are largely mitigated by the grooming procedure. In contrast, under a stronger grooming condition ($z_{\text{cut}}=0.5$, $\beta =1.5$), no significant changes in $M_g/p_{T,\text{jet}}$ are observed, indicating that the medium-induced modifications are predominantly associated with large-angle scattering.

    ↳ nucl-thhep-exhep-phnucl-exNucl.Sci.Tech.(2026)·3 citations
26. 26*

    Dark Energy Crosses the Line: Quantifying and Testing the Evidence for Phantom Crossing

    Emre Özülker🇬🇧 · Eleonora Di Valentino🇬🇧 · William Giarè🇬🇧

    Combinations of the most recent CMB, BAO, and SNeIa datasets, when analyzed using the CPL parametrization, $w(a)=w_0+(1-a)w_a$, exclude $\Lambda$CDM at $\gtrsim 3\sigma$ in favor of a dark energy equation of state (EoS) parameter that crosses the phantom divide. We confirm this behavior and show that it persists when DESI BAO data are replaced by SH0ES $H_0$ measurements, despite the known tension between these probes in the presence of CMB data. In both cases, the constraints favor a transition from an early-time phantom-like phase to a late-time quintessence-like phase, with the crossing occurring at different redshifts depending on the dataset combination. The probability that a phantom divide line (PDL) crossing does not occur within the expansion history is excluded at significance levels ranging between $3.1\sigma$-$5.2\sigma$. To investigate whether the apparent PDL crossing is a genuine feature preferred by the data or an artifact of the linear form of the CPL parametrization, we isolate the PDL crossing feature by introducing two modified versions of CPL that explicitly forbid it: CPL${}_{>a_{\mathrm{c}}}$ and CPL${}_{<a_{\mathrm{c}}}$. These models are physically motivated in that they phenomenologically capture the behavior of thawing and freezing scalar field scenarios. While previous studies have primarily considered thawing quintessence as a non-crossing alternative, we find that a freezing phantom-like model is the only one capable of performing comparably to CPL -- and only in a few cases. Nevertheless, across all dataset combinations considered, the standard CPL model consistently provides the best fit, strongly indicating that the data genuinely favor a PDL crossing.

    ↳ astro-ph.COgr-qchep-ph89 citations
27. 27*

    Constraining exotic high-$z$ reionization histories with Gaussian processes and the Cosmic Microwave Background

    Hanyu Cheng🇨🇳 · Ziwen Yin🇨🇳 · Eleonora Di Valentino🇬🇧 · David J. E. Marsh🇬🇧 · Luca Visinelli🇮🇹

    The large-angle polarization anisotropies in the Cosmic Microwave Background (CMB) arise from Thomson scattering of CMB photons off free electrons in the post-recombination Universe. In the standard $\Lambda$ cold dark matter cosmological model, the free electron density increases at redshifts $z\lesssim 10$ as the first stars form, reionizing the intergalactic medium. We use \emph{Gaussian processes} to perform a model-independent reconstruction of the cosmic reionization history constrained by \textit{Planck} CMB data. Our approach recovers the standard reionization at $z\lesssim 10$ and places stringent limits on any additional high-$z$ reionization. From this reconstruction, we define a new derived parameter, the high-redshift contribution to the CMB optical depth, ${\tau }_{\mathrm{highz}}$, whose posterior distribution provides robust constraints on exotic energy injection scenarios. We demonstrate this for decaying dark matter with particle masses in the range $\mathcal{O}(1\text{MeV})$. A companion paper applies this framework to multi-axion models. All data and code are publicly available at: \href{https://github.com/Cheng-Hanyu/CLASS_reio_gpr}{github.com/Cheng-Hanyu/CLASS\_reio\_gpr}.

    ↳ astro-ph.COhep-ph17 citations
28. 28*

    Holomorphic Unified Field Theory of Gravity and the Standard Model

    John. W. Moffat🇨🇦 · Ethan. J. Thompson🇨🇦

    We present a holomorphic framework in which gravity, gauge interactions, and their couplings to charges and currents emerge from a single geometric action on a four-complex-dimensional manifold. The Hermitian metric yields on the real slice $y^{\mu }=0$, a real symmetric metric $g_{(\mu \nu )}$ giving the vacuum Einstein equations, and an antisymmetric part $g_{[\mu \nu ]}$ that reproduces Maxwell's equations with sources. A single holomorphic gauge connection for $G_{\text{GUT}}$, such as $SU(5)$ or $SO(10)$, encodes all gauge sectors; its Bianchi identities give homogeneous Yang--Mills equations, and variation imposes ${\nabla }_{\mu }{F}_A^{\mu \nu }=J_A^{\nu }$. Chiral fermions arise from a holomorphic Dirac Lagrangian and couple minimally to all gauge fields, reproducing the Standard Model spectrum. Anomaly cancellation follows from holomorphic gauge invariance. A holomorphic adjoint Higgs breaks $G_{\text{GUT}}\to SU(3)\times SU(2)\times U(1)$ with unified coupling, and a second Higgs breaks electroweak symmetry, generating $W^{\pm }$, $Z$, and fermion masses. Below the unification scale, couplings run by standard renormalization-group flow. This construction unifies Einstein gravity, Yang--Mills theory, electromagnetism, and chiral fermions into a single classical geometric framework, and admits quantization via a holomorphic path integral that reproduces standard Feynman rules.

    ↳ physics.gen-phgr-qchep-phhep-thEPJC(2025)·6 citations
29. 29*

    Measurement of the $\Lambda$ Electric Dipole Moment with an Entangled Baryon-Antibaryon System

    BESIII Collaboration: M. Ablikim · M. N. Achasov · P. Adlarson · X. C. Ai · R. Aliberti · A. Amoroso · Q. An · Y. Bai · O. Bakina · Y. Ban · H.-R. Bao · S. S. Bao and 709 other authors

    The dominance of matter over antimatter in the universe has consistently driven the pursuit of new physics beyond the Standard Model that violates charge-parity symmetry. Strange baryons (hyperons) remain a largely unexplored territory in which interactions between hyperons and particles from new physics could induce a nontrivial electric dipole moment (EDM). However, direct measurements of hyperon EDMs through spin precession are highly challenging owing to their short lifetimes. In this work, we introduce a method to extract the EDM of the lightest hyperon, $\Lambda$, using the entangled $\Lambda$$\overline{\Lambda }$ system. Our result is consistent with zero, achieving a three-orders-of-magnitude improvement over the previous upper limit established in the 1980s with comparable statistics, providing stringent constraints on potential new physics.

    ↳ hep-exhep-phScience 393, 1027-1030(2026)·11 citations
30. 30*

    Vacuum energy in effective field theory of general relativity

    E. Epelbaum🇩🇪 · J. Gegelia🇩🇪 · Ulf-G. Meißner🇩🇪

    It is shown to all orders of perturbation theory that in the effective field theory of general relativity the condition of vanishing of the vacuum energy leads to the same value of the cosmological constant, viewed as a parameter of the effective Lagrangian, as obtained by demanding the consistency of the effective field theory in Minkowski background. The resulting effective action is characterized by the cosmological constant term that vanishes exactly.

    ↳ hep-thgr-qchep-phPRD(2025)·1 citation
31. 31*

    Searching for radio pulsars in old open clusters from the Parkes archive

    S.B. Zhang🇨🇳 · J. J. Wei🇨🇳 · X. Yang🇨🇳 · S. Dai🇨🇳 · J. S. Wang🇩🇪 · L. Toomey · S.Q. Wang🇦🇺 · G. Hobbs🇦🇺 · X. F. Wu🇨🇳 · L. Staveley-Smith

    Motivated by the discovery of a pulsar in the direction of the old open cluster NGC 6791, we conducted a search for radio pulsars in archival Parkes observations targeting similar old open clusters. We reprocessed 224 observations totalling 75.02 hours from four clusters: Theia 1661, NGC 6259, Pismis 3, and Trumpler 20. Our analysis identified five known pulsars and three new rotating radio transient (RRAT) candidates. By comparing the measured dispersion measures (DMs) with the expected DM values for each cluster derived from YMW16 and NE2001 models, we conclude that most detected sources are likely background pulsars. However, RRAT J1749-25 in Theia 1661 and RRAT J1237-60 in Trumpler 20 have DMs reasonably close to their respective clusters, suggesting possible membership. The association between PSR J1750-2536 and Theia 1661 remains ambiguous due to its intermediate DM. These candidate cluster-associated neutron stars warrant follow-up with more sensitive telescopes such as MeerKAT or the SKA, potentially offering valuable insights into neutron star retention mechanisms and evolution in open cluster environments.

    ↳ astro-ph.HEhep-phApJ(2025)·1 citation
32. 32*

    Making the $\mu$OST of the Muon Collider

    Henry T. Klest🇺🇸

    The Muon Collider, recently highlighted as Recommendation 1 in the U.S. National Academies report on Elementary Particle Physics, offers a unique opportunity for fixed-target experiments with high energy and luminosity. This paper outlines some of the challenges and possibilities for fixed-target experiments to study the multi-dimensional structure of hadrons at the Muon Collider. We present a sketch of an experiment making use of the high-energy muon beam from the Muon Collider that could serve as the next-generation hadronic physics experiment after the Electron-Ion Collider.

    ↳ nucl-exhep-exhep-phphysics.ins-detPRD(2025)·3 citations
33. 33*

    Higher co-dimension de Sitter branes

    Florian Niedermann🇸🇪 · Antonio Padilla🇬🇧

    We extend the arguments of Maldacena and Núñez to include higher co-dimension brane setups and derive a new no-go theorem. Specifically, we show that under reasonable assumptions on the energy-momentum conservation and the bulk curvature, co-dimension-two branes fail to support stable de Sitter solutions. For co-dimensions higher than two embedded in a compact internal space, we show that negative tension sources would be required. This result places strong constraints on the viability of higher-dimensional braneworld models as a means to obtain de Sitter space within string theory.

    ↳ hep-thastro-ph.COgr-qchep-phPRD(2025)·2 citations
34. 34*

    Perfect spinfluid: A divergence-type approach

    Nick Abboud🇺🇸 · Lorenzo Gavassino🇺🇸 · Rajeev Singh🇷🇴 · Enrico Speranza🇨🇭

    We present a new formulation of non-dissipative relativistic spin hydrodynamics that incorporates spin degrees of freedom into the divergence-type theory framework. Due to the divergence-type structure, it is straightforward to enforce non-linear causality and symmetric hyperbolicity of the equations of motion, ensuring local well-posedness of the initial-value problem and stability of the theory. Furthermore, in a specific realization based on spin kinetic theory, we prove that the equations of motion remain non-linearly causal and symmetric-hyperbolic to all orders in the spin potential, provided a specific thermodynamic constraint is satisfied. This framework can be applied for numerical simulations to study the dynamics of spin-polarized fluids, such as the quark-gluon plasma in heavy-ion collisions.

    ↳ nucl-thhep-phhep-thPRD(2025)·16 citations
35. 35*

    Chimera baryons and mesons on the lattice: a spectral density analysis

    Ed Bennett🇬🇧 · Luigi Del Debbio🇬🇧 · Niccolò Forzano🇬🇧 · Ryan Hill🇬🇧 · Deog Ki Hong🇰🇷 · Ho Hsiao🇹🇼 · Jong-Wan Lee🇰🇷 · C.-J. David Lin🇹🇼 · Biagio Lucini🇬🇧 · Alessandro Lupo🇫🇷 · Maurizio Piai🇬🇧 · Davide Vadacchino🇬🇧 · Fabian Zierler🇬🇧

    We develop and test a spectral-density analysis method, based on the introduction of smeared energy kernels, to extract physical information from two-point correlation functions computed numerically in lattice field theory. We apply it to a $Sp(4)$ gauge theory and fermion matter fields transforming in distinct representations, with $N_{\mathrm{f}}=2$ Dirac fermions in the fundamental and $N_{\mathrm{as}}=3$ in the 2-index antisymmetric representation. The corresponding continuum theory provides the minimal candidate model for a composite Higgs boson with partial top compositeness. We consider a broad class of composite operators, that source flavored mesons and (chimera) baryons, for several finite choices of lattice bare parameters. For the chimera baryons, which include candidate top-quark partners, we provide the first measurements, obtained with dynamical fermions, of the ground state and the lowest excited state masses, in all channels of spin, isospin, and parity. We also measure matrix elements and overlap factors, that are important to realize viable models of partial top compositeness, by implementing an innovative way of extracting this information from the spectral densities. For the mesons, among which the pseudoscalars can be reinterpreted to provide an extension of the Higgs sector of the Standard Model of particle physics, our measurements of the renormalized matrix elements and decay constants are new results. We complement them with an update of existing measurements of the meson masses, obtained with higher statistics and improved analysis. The analysis software is made publicly available, and can be used in other lattice studies, including application to quantum chromodynamics (QCD).

    ↳ hep-lathep-phPRD(2025)·9 citations
36. 36*

    Correlator Polytopes

    Carolina Figueiredo🇺🇸 · Francisco Vazão🇩🇪

    Recently, "cosmohedra" have been introduced as polytopes underlying the cosmological wavefunction for conformally coupled Tr(${\Phi }^3$) theory in FRW cosmologies, generalizing associahedra for flat space scattering amplitudes. In this letter we show that correlation functions are also directly captured by a new polytope - the "Correlatron". The combinatorics of correlation functions is an interesting blend of flat space scattering amplitudes and wavefunctions. This is reflected in the correlatron geometry, which is a one-higher dimensional polytope sandwiched between cosmohedron and associahedron facets. We provide an explicit embedding for the correlatron, which is a natural extension of the "shaving" picture for cosmohedra to one higher dimension. As a byproduct, we also define "graph correlahedra" as polytopes for the contribution to correlators from any fixed graph. We show how the canonical form of these polytopes directly computes the graph correlator, without the power of two weights seen in previous geometric formulations. Finally, we give a prescription for extracting the full correlator from the canonical form of the correlatron.

    ↳ hep-thhep-phmath.COPRD(2026)·19 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.