Thu·Nov 21, 2024Thursday·November 21, 2024

1. 01*

   Complete $\mathcal{O}({\alpha }_s^2)$ Corrections to the Leptonic Invariant Mass Spectrum in $b\to X_{c}l{\bar{\nu }}_l$ Decay

   Mateusz Czaja🇵🇱 · Mikołaj Misiak🇵🇱 · Abdur Rehman🇨🇦

   In the determination of the Cabibbo-Kobayashi-Maskawa matrix element $|V_{cb}|$ from inclusive semileptonic $B$-meson decays, moments of the leptonic invariant mass spectrum constitute valuable observables. To evaluate them with sufficient precision, perturbative $\mathcal{O}({\alpha }_s^2)$ corrections to the analogous spectrum in the partonic $b\to X_{c}l{\bar{\nu }}_l$ decay are necessary. In the present paper, we compute such perturbative corrections in a complete manner, including contributions from the triple-charm channel, namely from the $cc\bar{c}l{\bar{\nu }}_l$ final states. We present our results in terms of numerical fits in both the single- and triple-charm cases. We confirm the recently found results for the single-charm correction, and analyze the triple-charm channel impact on centralized moments of the spectrum.

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

   Equation of state of isospin asymmetric QCD with small baryon chemical potentials

   Bastian B. Brandt🇩🇪 · Gergely Endrodi🇩🇪 · G. Markó🇩🇪

   We extend our measurement of the equation of state of isospin asymmetric QCD to small baryon and strangeness chemical potentials, using the leading order Taylor expansion coefficients computed directly at non-zero isospin chemical potentials. Extrapolating the fully connected contributions to vanishing pion sources is particularly challenging, which we overcome by using information from isospin chemical potential derivatives evaluated numerically. Using the Taylor coefficients, we present, amongst others, first results for the equation of state along the electric charge chemical potential axis, which is potentially of relevance for the evolution of the early Universe at large lepton flavour asymmetries.

   hep-phhep-latnucl-thPoS(2025)·10 citations
3. 03*

   The unification in an $\widehat{\mathfrak{su}}(8{)}_{k_U=1}$ affine Lie algebra

   Ning Chen🇨🇳 · Zhanpeng Hou🇨🇳 · Zhaolong Teng🇨🇳

   A flavor-unified theory based on the simple Lie algebra of $\mathfrak{su}(8)$ was previously proposed to generate the observed Standard Model quark/lepton mass hierarchies and the Cabibbo-Kobayashi-Maskawa mixing pattern due to their non-universal symmetry properties. A level-$1$ affine Lie algebra of $\widehat{\mathfrak{su}}(8{)}_{k_U=1}$ with the $\mathcal{N}=1$ supersymmetric extension is found to unify three gauge couplings through the maximally symmetry breaking pattern.

   hep-phhep-thJHEP(2025)·3 citations
4. 04*

   Polarization of an electron scattered by static potentials

   Hao-Hao Peng🇨🇳 · Ren-Hong Fang🇨🇳

   We study the polarization of an electron scattered by different static potentials. The initial state of the electron is chosen as a wavepacket to construct the definite orbital angular momentum, and the final polarization of the electron, scattered by different static potentials such as vector, pseudovector, scalar and pseudoscalar potentials, is calculated. Numerical results show that, the sign of the polarization of the electron scattered by the vector potential is opposite to the other three cases, and the magnitude order of the polarization value is consistent with recent experimental result in the collision parameter range $0<b<2\mathrm{fm}$.

   hep-ph0 citations
5. 05*

   Quark Model Study of Doubly Heavy $\Xi$ and $\Omega$ Baryons via Deep Neural Network and Hybrid Optimization

   Zahra Ghalenovi🇮🇷 · Masoumeh Moazzen Sorkhi🇮🇷 · Amir Hossein Sovizi🇮🇷

   In the present work we investigate the mass spectrum and semileptonic decays of double charm and bottom baryon states using the hypercentral quark model. We solve the six-dimensional Schrödinger equation via deep learning and particle swarm optimization techniques to improve the speed and accuracy. Then, we predict the masses of the ground and excited states of single and doubly heavy baryons. Working close to the zero recoil point, we also study the semileptonic decay widths and branching ratios of doubly heavy $\Xi$ and $\Omega$ baryons for the $b\to c$ transitions. A comparison between our results and the evaluations of other theoretical models is also presented. Our predictions of mass spectrum and decay widths provide valuable information for the experiment searching for undiscovered heavy baryon states.

   hep-phMod.Phys.Lett.A(2025)·1 citation
6. 06*

   Baryogenesis from a Majorana Fermion Coupled to Quarks

   Shrihari Gopalakrishna🇮🇳 · Rakesh Tibrewala🇮🇳

   In the theory with a Majorana fermion ($X$) coupled to quark-like fermions ($Q$) via a dimension-six four-fermion vector-vector interaction, we have computed in an earlier work the baryon asymmetry generated in the decay and scattering processes of the $X$ with $Q$. In this work we consider such processes in the expanding early Universe, set up the Boltzmann equations governing the $X$ and net baryon number densities, and numerically solve them in example benchmark points, taking the thermally averaged decay and scattering rates and their temperature dependence from the earlier study. We find that starting from a baryon symmetric Universe at early time, the presently observed baryon asymmetry of the Universe (BAU) can be explained in this theory over a wide range of mass scales, $M_{\chi }\in (10^4,10^{16})$ GeV for appropriately chosen couplings. We find that scattering processes play a crucial role in generating the baryon asymmetry in this theory. We present our results in a general manner that should be useful not just in our theory, but also in other related theories that share the essential ingredients. Our results should help guide promising ways to probe such new physics in terrestrial experiments. For instance, in regions of parameter space that yield the observed BAU, we present the rate for neutron-antineutron oscillation and discuss the prospects for observing this in upcoming experiments.

   hep-phPRD(2025)·3 citations
7. 07*

   Path-length dependence of parton and jet energy loss from universal scaling laws

   François Arleo🇫🇷 · Guillaume Falmagne🇺🇸

   The universal dependence of hadron suppression, $R_{\mathrm{AA}}(p_{\perp })$, observed at large-$p_{\perp }$ in heavy ion collisions at RHIC and LHC allows for a systematic determination of the average parton energy loss $⟨ϵ⟩$ in quark-gluon plasma (QGP). A simple relation between $⟨ϵ⟩$ and the soft particle multiplicity allows for probing the dependence of parton energy loss on the medium path-length. We find that all the available measurements are consistent with $⟨ϵ⟩\propto L^{\beta }$ with $\beta =1.02{\pm }_{0.06}^{0.09}$, consistent with the pQCD expectation of parton energy loss in a longitudinally expanding QGP. We then show, based on the model predictions, that the data on the azimuthal anisotropy coefficient divided by the collision eccentricity, $v_2/\mathrm{e}$, follows the same scaling property as $R_{\mathrm{AA}}$. Finally, a linear relationship between $v_2/\mathrm{e}$ and the logarithmic derivative of $R_{\mathrm{AA}}$ at large $p_{\perp }$ offers a purely data-driven access to the $L$ dependence of parton energy loss. Quite remarkably, both hadron and jet measurements obey this latter relationship, moreover with consistent values of $\beta$. This points to the same parametric path-length dependence of parton and jet energy loss in QGP.

   hep-phhep-exPoS(2025)·0 citations
8. 08*

   A 95 GeV Higgs Boson in the $U(1{)}_X$SSM

   Song Gao🇨🇳 · Shu-Min Zhao🇨🇳 · Shuang Di🇨🇳 · Xing-Xing Dong🇨🇳 · Tai-Fu Feng🇨🇳

   The CMS and ATLAS Collaborations have recently reported their findings based on the comprehensive run 2 dataset, detailing their searches for a light Higgs boson with a mass of approximately 95 GeV. We investigate the excesses observed in the $\gamma \gamma$ and $b\bar{b}$ data at approximately 95 GeV in the $U(1{)}_X$ extension of the minimal supersymmetric standard model ($U(1{)}_X$SSM). Additionally, it also mixes with the SM-like Higgs boson. Research indicates that, in this model, identifying the mixture of the singlet Higgs states as the lightest Higgs boson holds tremendous potential for explaining the excess observed at approximately 95 GeV. In our calculations, we maintain the masses of the lightest and next-to-lightest Higgs bosons at approximately 95 GeV and 125 GeV, respectively. The study finds that the theoretical predictions for the signal strengths $\mu (h_{95}{)}_{\gamma \gamma }$ and $\mu (h_{95}{)}_{b\bar{b}}$ in the $U(1{)}_X$SSM align well with the excesses observed by CMS.

   hep-phNPB(2025)·12 citations
9. 09*

   Pentaquarks and Maxim V. Polyakov

   Hyun-Chul Kim🇰🇷

   This brief review is dedicated to the memory of Maxim V. Polyakov and his pioneering contributions to pentaquark physics. We focus on his seminal 1997 work with Diakonov and Petrov that predicted the ${\Theta }^{+}$ pentaquark, a breakthrough that initiated an intense period of research in hadron physics. The field faced a significant setback when the CLAS Collaboration at Jefferson Lab reported null results in 2006, leading to a dramatic decline in light pentaquark research. Nevertheless, Maxim maintained his scientific conviction, supported by continued positive signals from DIANA and LEPS collaborations. Through recent experimental findings on the ${\Theta }^{+}$ and the nucleon-like resonance $N^{\ast }(1685)$, we examine how Polyakov's theoretical insights, particularly the prediction of a narrow width ($\Gamma \approx 0.5$-$1.0$ MeV), remain relevant to our understanding of the ${\Theta }^{+}$ light pentaquark.

   hep-phhep-exActa Phys.Polon.B(2025)·3 citations
10. 10*

    Gravitational Waves from Metastable Cosmic Strings in Supersymmetric New Inflation Model

    Akifumi Chitose🇯🇵 · Masahiro Ibe🇯🇵 · Shunsuke Neda🇯🇵 · Satoshi Shirai🇯🇵

    Recent observations by pulsar timing arrays (PTAs) indicate a potential detection of a stochastic gravitational wave (GW) background. Metastable cosmic strings have been recognized as a possible source of the observed signals. In this paper, we propose an $R$-invariant supersymmetric new inflation model. It is characterized by a two-step symmetry breaking $\mathrm{SU}(2)\to \mathrm{U}(1{)}_G\to \mathrm{nothing}$, incorporating metastable cosmic strings. The field responsible for the initial symmetry breaking acts as the inflaton, while the second symmetry breaking occurs post-inflation, ensuring the formation of the cosmic string network without monopole production. Our model predicts symmetry breaking scales consistent with the string tensions favored by PTA data, $G_{\mathrm{N}}{\mu }_{\mathrm{str}}\sim 10^{-5}$, where $G_{\mathrm{N}}$ is the Newton constant. Notably, a low reheating temperature is required to suppress non-thermal gravitino production from the decay of inflaton sector fields. This also helps evading LIGO-Virgo-KAGRA constraints, while yielding a distinctive GW signature that future PTA and interferometer experiments can detect. Additionally, we examine the consistency of this scenario with non-thermal leptogenesis and supersymmetric dark matter.

    hep-phastro-ph.COJCAP(2025)·12 citations
11. 11*

    Two-pion exchange for coupled-channel scattering of two heavy mesons

    J.T. Chacko🇩🇪 · V. Baru🇩🇪 · C. Hanhart🇩🇪 · S.L. Krug🇩🇪

    To improve the theoretical understanding of multiquark states like $Z_b(10610)$ and $Z_b(10650)$, we calculate the heavy-meson heavy-(anti)meson scattering potential up to next-to-leading order, $O(Q^2)$, within chiral effective field theory ($\chi$EFT) employing a power counting scheme that explicitly keeps track with the large momentum scale $Q\sim \sqrt{2\mu \delta }$ (where $\delta =m_V-m_P$ is the vector-pseudoscalar mass difference and $\mu$ their reduced mass) introduced by the coupled channel dynamics. We provide expressions for the two-pion exchange (TPE) terms up to $O(Q^2)$ and their partial-wave decomposition. We show that these potentials are well-approximated by contact terms at $O(Q^2)$, with minor residual non-analytic TPE contributions, supporting $\chi$EFT convergence in the theoretical predictions for $Z_b(10610)$ and $Z_b(10650)$, as well as their spin partners. These findings are also relevant for $D^{(\ast )}{D}^{(\ast )}$ scattering, especially for the $T_{cc}$ state, for both physical and lattice QCD data with moderately larger pion masses. We further demonstrate that the differences between isovector and isoscalar potentials for heavy mesons are naturally explained by the TPE contributions.

    hep-phnucl-thPRD(2025)·11 citations
12. 12*

    Radiative Mass Mechanism: Addressing the Flavour Hierarchy and Strong CP Puzzle

    Gurucharan Mohanta🇮🇳

    We propose a class of models based on the parity invariant Left-Right Symmetric Model (LRSM), which incorporates the mechanism of radiative generation of fermion masses while simultaneously possessing the solution to the Strong CP problem. A flavour non-universal gauged abelian symmetry is imposed on top of LRSM, which helps in inducing the masses of second and first-generation fermions at one-loop and two-loop, respectively, and thereby reproduces the hierarchical spectrum of the masses. Parity invariance requires the vanishing of the strong CP parameter at the zeroth order, and the non-zero contribution arises at the two-loop level, which is in agreement with the experimental constraints. The minimal model predicts flavour symmetry breaking scale and the $SU(2{)}_R$ symmetry breaking scale at the same level. flavour non-universality of the new gauge interaction leads to various flavour-changing transitions both in quarks and leptonic sectors and, therefore, has various phenomenologically interesting signatures. The model predicts a new physics scale near $10^8$ GeV or above for phenomenological consistent solutions. This, in turn, restricts strong CP phase $\bar{\theta }\lesssim 10^{-14}$ as the parity breaking scale and flavour scale are related in the minimal framework.

    hep-phhep-thJHEP(2025)·3 citations
13. 13*

    Dispersive Determination of Nucleon Gravitational Form Factors

    Xiong-Hui Cao🇨🇳 · Feng-Kun Guo🇨🇳 · Qu-Zhi Li🇨🇳 · De-Liang Yao🇨🇳

    Being closely connected to the origin of the nucleon mass, the gravitational form factors of the nucleon have attracted significant attention in recent years. We present the first model-independent determinations of the gravitational form factors of the pion and nucleon at the physical pion mass, using a data-driven dispersive approach. The so-called "last global unknown property" of the nucleon, the $D$-term, is determined to be $-3.38_{-0.35}^{+0.34}$. The root mean square radius of the scalar trace density inside the nucleon is determined to be $(0.97\pm 0.03)\text{fm}$. Notably, this value is larger than the proton charge radius, suggesting a modern structural view of the nucleon where gluons, responsible for most of the nucleon mass, are distributed over a larger spatial region than quarks, which dominate the charge distribution, indicating that the radius of the trace density may be regarded as a confinement radius. We also predict the nucleon angular momentum and mechanical radii, providing further insights into the intricate internal structure of the nucleon.

    hep-phhep-exhep-latnucl-ex+1Nature Commun.(2025)·57 citations
14. 14*

    Quasi-Classical Evaluation of Gluon Saturation Induced Helicity Effects

    Ming Li🇺🇸

    At sub-eikonal order in the high-energy limit, helicity dependences are generally contained in the transverse components of the gluon field. In the gluon saturation regime, novel helicity effects arise from the nonlinear interaction between the eikonal-order longitudinal gluon field and the sub-eikonal-order transverse gluon field. We derive this saturation induced helicity-dependent field both by solving the classical Yang-Mills equations and through direct diagrammatic calculations. Our analysis shows that the saturation induced helicity effect is intrinsically a two-particle (or multi-particle) correlation effect, rather than a single-particle distribution effect. Furthermore, we evaluate this effect in the context of double-spin asymmetry for incoherent diffractive dijet production in longitudinally polarized electron-nucleus collisions, using a simplified helicity-extended McLerran-Venugopalan model. We find that the saturation induced helicity effect further suppresses the back-to-back peak in the dijet azimuthal angle correlation, with a magnitude comparable to that of the direct helicity effect. This gluon saturation induced helicity effect may offer a novel avenue to probe gluon saturation in polarized collisions.

    hep-phPRD(2025)·9 citations
15. 15*

    Summary of the 16th Applied Antineutrino Physics Workshop 2023

    Liz Kneale🇺🇸 · Viacheslav Li🇺🇸

    Summary of the 16th Applied Antineutrino Physics Workshop 2023, held in the historic Guildhall in York in the UK from the 18th - 21st September 2023.

    hep-phhep-ex0 citations
16. 16*

    $H\to ZZ$ as a double-slit experiment

    J. A. Aguilar-Saavedra🇪🇸

    The decay $H\to ZZ\to 4\ell$, with $\ell =e,\mu$, can be used to test quantum interference in analogy to the famous double-slit experiment. The observations corresponding to `covering a slit' can be extracted from data in the $ee\mu \mu$ channel, while the observations when both `slits' are open, which include the interference, are measured in the $4e/4\mu$ channels. In this way, this process offers a unique opportunity to investigate identical-particle effects at high energies, and provide the first evidence of identical-particle behaviour for muons. Sensitivity at the $4\sigma$ level could be achieved at the high-luminosity upgrade of the Large Hadron Collider.

    hep-phhep-exquant-phPLB(2025)·14 citations
17. 17*

    The two-loop fully differential soft function for $Q\bar{Q}V$ production at lepton colliders

    Ze Long Liu🇨🇳 · Pier Francesco Monni🇨🇭

    We consider the production of a pair of heavy quarks $Q\bar{Q}$ in association with a generic colour singlet system $V$ at lepton colliders, and present the first analytic calculation of the two-loop soft function differential in the total momentum of the real radiation. The calculation is performed by reducing the relevant Feynman integrals into a canonical basis of master integrals by means of integration-by-parts identities. The resulting integrals are then evaluated by solving a system of differential equations in the kinematic invariants, whose boundary conditions are determined analytically with some care due to the presence of Coulomb singularities. The fully differential soft function is expressed in terms of Goncharov polylogarithms. This result is an essential ingredient for a range of N${}^3$LL resummations for key collider observables at lepton colliders, such as the $Q\bar{Q}V$ production cross section at threshold and observables sensitive to the total transverse momentum of the radiation in heavy-quark final states. Moreover, it constitutes the complete final-final dipole contribution to the fully differential soft function needed for the description of $Q\bar{Q}V$ production at hadron colliders, which plays an important role in the LHC physics programme.

    hep-phJHEP(2025)·15 citations
18. 18*

    DW-genesis: baryon number from domain wall network collapse

    Alberto Mariotti🇧🇪 · Xander Nagels🇧🇪 · Aäron Rase🇧🇪 · Miguel Vanvlasselaer🇧🇪

    Axionic domain walls, as they move through the early universe plasma during their collapse, can generate a net baryon and lepton number through the mechanism of spontaneous baryogenesis, provided that there is a coupling between the axion and the lepton or baryon current. In this paper, we study systematically the baryon asymmetry produced by these domain walls (DWs) at annihilation, within different realisations of the $L$- or $B$-violating sector, and refer to this process as DW-genesis. We find that the baryon number is maximised when the DW network collapses approximately at the moment when the $L$- or $B$-violating interaction decouples. We study a model of minimal leptogenesis, a model of cogenesis, a model of baryogenesis and finally the possibility that the baryon asymmetry is produced by electroweak sphalerons. As phenomenological consequences of DW-genesis, we discuss the expected gravitational wave signal from the DW network annihilation and the prospects for detecting it. However, we finally emphasize that in realisations of the DW-genesis in minimal post-inflationary scenarios, there is a suppression induced by the cancellation between the asymmetry created by "opposite" axionic domain walls attached to the string. We quantify the impact of this cancellation and discuss possible ways to avoid it.

    hep-phJHEP(2025)·14 citations
19. 19*

    Global analysis of $\mu \to e$ interactions in the SMEFT

    Filippo Delzanno🇺🇸 · Kaori Fuyuto🇺🇸 · Sergi Gonzàlez-Solís🇺🇸 · Emanuele Mereghetti🇺🇸

    We study current experimental bounds on charged lepton flavor violating (CLFV) $\mu$-$e$ interactions in the model-independent framework of the Standard Model Effective Field Theory (SMEFT). Assuming a generic flavor structure in the quark sector, we consider the contributions of CLFV operators to low-energy observables, including $\mu \to e\gamma$ and $\mu \to e$ conversion for quark-flavor conserving operators and CLFV meson decays for quark-flavor violating operators. At high energy, we consider limits on CLFV decays of the Higgs and Z bosons and of the top quark, and obtain bounds on operators with light quarks by recasting searches for production of $e\mu$ pairs in $pp$ collisions at the Large Hadron Collider (LHC). We connect observables at low- and high-energy by taking into account renormalization group running and matching between CLFV operators. We also discuss the sensitivity of the future Electron-Ion Collider, where the prospective bounds are derived by imposing simple cuts on final state particles. We find that, in a single operator scenario, bounds on purely leptonic operators are dominated by $\mu \to e\gamma$ and $\mu \to e$ conversion. Semileptonic operators with down-type quarks are also dominantly constrained by low-energy observables, while LHC searches lead the bounds on up-type quark-flavor violating operators. Taking simplified multiple-coupling scenarios, we show that it is easy to evade the strongest low-energy bounds from spin-independent $\mu \to e$ conversion, and that collider searches are competitive and complementary to constraints from spin-dependent $\mu \to e$ conversion and other low-energy probes.

    hep-phhep-exnucl-thJHEP(2025)·13 citations
20. 20*

    Localized Electromagnetic Perturbations on Vector Solitons

    Yulia Galushkina🇷🇺 · Eduard Kim🇷🇺 · Emin Nugaev🇷🇺 · Yakov Shnir🇷🇺

    Using effective field theory approach one can describe localization of electromagnetic field on a non-topological soliton. Pursuing this aim we consider the U(1) gauge theory with gauge kinetic coupling to a self-interacting complex neutral Proca field. The model possesses single energy scale given by the vector boson mass. Considering spherically symmetric stationary configurations, we study vibrational modes of the Proca field on the background of the soliton and discuss their properties.

    hep-phhep-thPLB(2025)·2 citations
21. 21*

    Finite-size effects on small-$x$ evolution and saturation in proton and nuclear targets

    Heikki Mäntysaari🇫🇮 · Jani Penttala🇺🇸 · Farid Salazar🇺🇸 · Björn Schenke🇺🇸

    Within the Color Glass Condensate effective field theory, we assess the importance of including a finite size for the target on observables sensitive to small-$x$ evolution. To this end, we study the Balitsky-Kovchegov (BK) equation with impact-parameter dependence in the initial condition. We demonstrate that neglecting the dependence on the impact parameter can result in overestimated saturation effects for protons, while it has little effect for heavy nuclei at the energies available at current experiments. When fixing the nonperturbative parameters to the energy dependence of the exclusive $J/\psi$ photoproduction cross section with proton targets, predictions for lead targets are not sensitive to the applied running-coupling prescription, the scheme chosen to resum large transverse logarithms in the BK equation, or the infrared regulator in the evolution.

    hep-phnucl-thPRD(2025)·29 citations
22. 22*

    Living dangerously with decoupled first/second generation scalars: SUSY prospects at the LHC

    Howard Baer🇺🇸 · Vernon Barger🇺🇸 · Kairui Zhang🇺🇸

    The string landscape statistical draw to large scalar soft masses leads to a mixed quasi-degeneracy/decoupling solution to the SUSY flavor and CP problems where first/second generation matter scalars lie in the 20-40 TeV range. With increasing first/second generation scalars, SUSY models actually become more natural due to two-loop RG effects which suppress the corresponding third generation soft masses. This can also lead to substantial parameter space regions which are forbidden by the presence of charge and/or color breaking (CCB) minima of the scalar potential. We outline the allowed SUSY parameter space for the gravity-mediated three extra-parameter-non-universal Higgs model NUHM3. The natural regions with m_h~ 125 GeV, \Delta_{EW}<~ 30 and decoupled first/second generation scalar are characterized by rather heavy gluinos and EW gauginos, but with rather small \mu and top-squarks not far beyond LHC Run 2 limits. This scenario also explains why SUSY has so far eluded discovery at LHC in that the parameter space with small scalar and gaugino masses is all excluded by the presence of CCB minima.

    hep-phhep-thPRD(2025)·7 citations
23. 23*

    Individual Neutrino Masses From a Supernova

    Peter B. Denton🇺🇸 · Yves Kini🇳🇱

    A nearby supernova will carry an unprecedented wealth of information about astrophysics, nuclear physics, and particle physics. Because supernova are fundamentally neutrino driven phenomenon, our knowledge about neutrinos -- particles that remain quite elusive -- will increase dramatically with such a detection. One of the biggest open questions in particle physics is related to the masses of neutrinos. Here we show how a galactic supernova provides information about the masses of each of the three mass eigenstates \emph{individually}, at some precision, and is well probed at JUNO. This information comes from several effects including time delay and the MSW effect within the supernova. The time delay feature is strongest during a sharp change in the flux such as the neutronization burst; additional information may also come from a QCD phase transition in the supernova or if the supernova forms a black hole. We consider both standard cases as dictated by local oscillation experiments as well as new physics motivated scenarios where neutrino masses may differ across the galaxy.

    hep-phastro-ph.HEPRD(2025)·7 citations
24. 24*

    Bounds on the bubble wall velocity

    Wen-Yuan Ai🇬🇧 · Benoit Laurent🇨🇦 · Jorinde van de Vis🇨🇭

    Determining the bubble wall velocity in first-order phase transitions is a challenging task, requiring the solution of (coupled) equations of motion for the scalar field and Boltzmann equations for the particles in the plasma. The collision terms appearing in the Boltzmann equation present a prominent source of uncertainty as they are often known only at leading log accuracy. In this paper, we derive upper and lower bounds on the wall velocity, corresponding to the local thermal equilibrium and ballistic limits. These bounds are completely independent of the collision terms. For the ballistic approximation, we argue that the inhomogeneous plasma temperature and velocity distributions across the bubble wall should be taken into account. This way, the hydrodynamic obstruction previously observed in local thermal equilibrium is also present for the ballistic approximation. This is essential for the ballistic approximation to provide a lower bound on the wall velocity. We use a model-independent approach to study the behaviour of the limiting wall velocities as a function of a few generic parameters, and we test our developments in the singlet extended Standard Model.

    hep-phastro-ph.COJHEP(2025)·48 citations
25. 25*

    Entanglement entropy of a color flux tube in (1+1)D Yang-Mills theory

    Rocco Amorosso🇺🇸 · Sergey Syritsyn🇺🇸 · Raju Venugopalan🇺🇸

    In recent work arxiv:2410.00112 , we computed a novel flux tube entanglement entropy (FTE${}^2$) of the color flux tube stretched between a heavy quark-antiquark pair on a Euclidean lattice in (2+1)D Yang-Mills theory. Our numerical results suggested that FTE${}^2$ can be partitioned into an internal color entanglement entropy and a vibrational entropy corresponding to the transverse excitations of a QCD string, with the latter described by a thin string model. Since the color flux tube does not have transverse excitations in (1+1)D, we analytically compute the contribution of the internal color degrees of freedom to FTE${}^2$ in this simpler framework. For the multipartite partitioning of the color flux tube, we find the remarkable result that FTE${}^2$ only depends on the number of times the flux tube crosses the border between two spatial regions, and the dimension of the representation of the color group, but not on the string length. The result holds independently of whether the branching points are placed on the vertices of the lattice or in the center of plaquettes.

    ↳ hep-lathep-phhep-thnucl-thPLB(2025)·19 citations
26. 26*

    On-shell approach to scalar hair in spinning binaries

    Adam Falkowski🇫🇷 · Panagiotis Marinellis🇫🇷

    We propose an on-shell description of spinning binary systems in gravitational theories where compact objects display scalar hair. The framework involves matter particles of arbitrary spin which, in addition to the minimal coupling to gravitons, are conformally coupled to a massless scalar mediating non-standard interactions. We use the unitary factorization techniques to derive the on-shell amplitudes relevant for emission of scalars and gravitons in matter scattering, paying attention to parametrize the freedom due to contact terms. Using the KMOC formalism, these amplitudes allow one to derive succinct expressions for the radiation waveforms at the leading post-Minkowskian order, together with the associated memory effects. Furthermore, we compute the power emitted via gravitational and scalar radiation in hyperbolic encounters of compact objects. After a continuation to bound orbits, these are compared with results obtained in specific scalar-tensor theories where black holes exhibit scalar hair, such as the scalar-Gauss-Bonnet or dynamical Chern-Simons theories. Finally, we identify possible deformations from the conformal coupling that can contribute to radiation observables at the same post-Newtonian order.

    ↳ hep-thgr-qchep-phJHEP(2025)·8 citations
27. 27*

    Picolensing as a Probe of Primordial Black Hole Dark Matter

    Michael A. Fedderke🇨🇦 · Sergey Sibiryakov🇨🇦

    The gravitational-lensing parallax of gamma-ray bursts (GRBs) is an intriguing probe of primordial black hole (PBH) dark matter in the asteroid-mass window, $2\times 10^{-16}{M}_{\odot }\lesssim M_{\text{PBH}}\lesssim 5\times 10^{-12}{M}_{\odot }$. Recent work in the literature has shown exciting potential reach for this "picolensing" signal if a future space mission were to fly two x-/$\gamma$-ray detectors in the Swift/BAT class, with inter-spacecraft separation baselines on the order of the Earth-Moon distance. We revisit these projections with a view to understanding their robustness to various uncertainties related to GRBs. Most importantly, we investigate the impact of uncertainties in observed GRB angular sizes on reach projections for a future mission. Overall, we confirm that picolensing shows great promise to explore the asteroid-mass window; however, we find that previous studies may have been too optimistic with regard to the baselines required. Detector baselines on the order of at least the Earth-L2 distance would make such a mission more robust to GRB size uncertainties; baselines on the order of an astronomical unit (AU) would additionally enable reach that equals or exceeds existing microlensing constraints up to $M_{\text{PBH}}\sim 2\times 10^{-8}{M}_{\odot }$.

    ↳ astro-ph.HEastro-ph.COhep-phPRD(2025)·11 citations
28. 28*

    Updates on the density of states method in finite temperature symplectic gauge theories

    David Mason🇬🇧 · Ed Bennett🇬🇧 · Biagio Lucini🇬🇧 · Maurizio Piai🇬🇧 · Enrico Rinaldi🇯🇵 · Davide Vadacchino🇬🇧 · Fabian Zierler🇬🇧

    First-order phase transitions in the early universe have rich phenomenological implications, such as the production of a potentially detectable signal of stochastic relic background gravitational waves. The hypothesis that new, strongly coupled dynamics, hiding in a new dark sector, could be detected in this way, via the telltale signs of its confinement/deconfinement phase transition, provides a fascinating opportunity for interdisciplinary synergy between lattice field theory and astro-particle physics. But its viability relies on completing the challenging task of providing accurate theoretical predictions for the parameters characterising the strongly coupled theory. Density of states methods, and in particular the linear logarithmic relaxation (LLR) method, can be used to address the intrinsic numerical difficulties that arise due the meta-stable dynamics in the vicinity of the critical point. For example, it allows one to obtain accurate determinations of thermodynamic observables that are otherwise inaccessible, such as the free energy. In this contribution, we present an update on results of the analysis of the finite temperature deconfinement phase transition in a pure gauge theory with a symplectic gauge group, $Sp(4)$, by using the LLR method. We present a first analysis of the properties of the transition in the thermodynamic limit, and provide a road map for future work, including a brief preliminary discussion that will inform future publications.

    ↳ hep-latastro-ph.COhep-phPoS(2025)·3 citations
29. 29*

    Exploring the effects of dark matter - dark energy interaction on cosmic evolution in viscous dark energy scenario

    Ashadul Halder🇮🇳 · Madhurima Pandey🇮🇳 · Rupa Basu🇮🇳 · Debasish Majumdar🇮🇳

    We explore the influence of interactions between dark matter (DM) and dark energy (DE) on the cosmic evolution of the Universe within a viscous dark energy (VDE) framework. Moving beyond traditional interacting dark energy (IDE) models, we propose a generalized IDE model adaptable to diverse IDE scenarios via IDE coupling parameters. In order to investigate deviations from $\Lambda$CDM across cosmic epochs by highlighting how viscous and the interactions between DM and DE impact cosmic density and expansion rates, we consider a model agnostic form of VDE. Eventually we perform a Bayesian analysis using the Union 2.1 Supernova Ia dataset and Markov Chain Monte Carlo (MCMC) sampling to obtain optimal values of model parameters. This comprehensive analysis provides insights about the interplay between viscous and IDE in shaping the Universe's expansion history.

    ↳ astro-ph.COgr-qchep-phEur.Phys.J.Plus(2025)·0 citations
30. 30*

    Quantum Attention for Vision Transformers in High Energy Physics

    Alessandro Tesi · Gopal Ramesh Dahale🇮🇳 · Sergei Gleyzer🇺🇸 · Kyoungchul Kong🇺🇸 · Tom Magorsch🇩🇪 · Konstantin T. Matchev🇺🇸 · Katia Matcheva🇺🇸

    We present a novel hybrid quantum-classical vision transformer architecture incorporating quantum orthogonal neural networks (QONNs) to enhance performance and computational efficiency in high-energy physics applications. Building on advancements in quantum vision transformers, our approach addresses limitations of prior models by leveraging the inherent advantages of QONNs, including stability and efficient parameterization in high-dimensional spaces. We evaluate the proposed architecture using multi-detector jet images from CMS Open Data, focusing on the task of distinguishing quark-initiated from gluon-initiated jets. The results indicate that embedding quantum orthogonal transformations within the attention mechanism can provide robust performance while offering promising scalability for machine learning challenges associated with the upcoming High Luminosity Large Hadron Collider. This work highlights the potential of quantum-enhanced models to address the computational demands of next-generation particle physics experiments.

    ↳ quant-phcs.LGhep-exhep-ph5 citations
31. 31*

    Quantum gravitational decoherence of a mechanical oscillator from spacetime fluctuations

    Sandro Donadi🇬🇧 · Matteo Fadel🇨🇭

    We consider the scenario of a fluctuating spacetime due to a deformed commutation relation with a fluctuating deformation parameter, or to a fluctuating metric tensor. By computing the resulting dynamics and averaging over these fluctuations, we find that a system experiences a decoherence in the momentum basis. We studied the predictions of the model for a free particle and an harmonic oscillator. Using experimental data taken from a mechanical oscillator prepared in quantum states of motion, we put a bound on the free parameters of the considered model. In addition, we comment on how these measurements can also provide bounds to other phenomenological quantum gravity models, such as the length scale for nonlocal dynamics.

    ↳ quant-phgr-qchep-phhep-thPRD(2025)·9 citations
32. 32*

    Cosmological Correlators at the Loop Level

    Zhehan Qin🇨🇳

    Cosmological correlators encode rich information about physics at the Hubble scale and may exhibit characteristic oscillatory signals due to the exchange of massive particles. Although many 1-loop processes, especially those that break de Sitter (dS) boosts, can generate significant leading signals for various particle models in cosmological collider physics, the precise results for these correlators or their full signals remain unknown due to the lack of symmetry. In this work, we apply the method of partial Mellin-Barnes (PMB) representation to the calculation of cosmological correlators at the loop level. As a first step, we use the PMB representation to calculate four-point cosmological correlators with bubble topology. We find that both the nonlocal and local signals arise from the factorized part, validating the cutting rules proposed in previous work, and are free from UV divergence. Furthermore, the UV divergence originates solely from the background piece and can be manifestly canceled by introducing the appropriate counterterm, similar to the procedure in flat spacetime. We also demonstrate how to renormalize the 1-loop correlators in Mellin space. After a consistency check with known results for the covariant case, we provide new analytical results for the signals generated from a nontrivial dS-boost-breaking bubble.

    ↳ hep-thastro-ph.COhep-phJHEP(2025)·41 citations
33. 33*

    Do Observations Prefer Thawing Quintessence?

    Guillaume Payeur🇨🇦 · Evan McDonough🇨🇦 · Robert Brandenberger🇨🇦

    In light of recent observations by the Dark Energy Spectroscopic Instrument (DESI), we study evidence for thawing quintessence over a cosmological constant as dark energy, with emphasis on the effect of the choice of priors. Working with a parametrization for the equation of state parameter motivated by the theory, we analyse the DESI BAO data jointly with Planck 2018 and Pantheon+ or Dark Energy Survey supernovae data, and find a preference for thawing quintessence compared to a bare cosmological constant only if we use priors which are heavily informed by the data itself. If we extend the priors to physically better motivated ranges, the evidence for thawing quintessence disappears.

    ↳ astro-ph.COgr-qchep-phhep-thPRD(2025)·45 citations
34. 34*

    Lattice QCD and the Neutron Electric Dipole Moment

    Keh-Fei Liu🇺🇸

    The recent lattice QCD calculations of the neutron and proton electric dipole moments (EDMs) and the CP-violating $\pi \mathrm{NN}$ coupling constant due to the $\theta$ term are reviewed. Progress towards nucleon EDM calculations, including the Weinberg three-gluon operator, and the quark chromoelectric dipole moment operator and their renormalization, is also discussed.

    ↳ hep-lathep-phnucl-exnucl-thAnn.Rev.Nucl.Part.Sci.(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.