Thu·Jul 25, 2024Thursday·July 25, 2024

1. 01*

   Discovery Potential of Future Electron-Positron Colliders for a 95 GeV Scalar

   Pramod Sharma🇿🇦 · Anza-Tshilidzi Mulaudzi🇿🇦 · Karabo Mosala🇿🇦 · Thuso Mathaha🇿🇦 · Mukesh Kumar🇿🇦 · Bruce Mellado🇿🇦 · Andreas Crivellin🇨🇭 · Maxim Titov🇫🇷 · Manqi Ruan🇨🇳 · Yaquan Fang🇨🇳

   The Large Electron Positron collider observed an indication for a new Higgs boson with a mass around $95$\,GeV-$100$\,GeV in the process $e^{+}{e}^{-}\to Z^{\ast }\to ZS$ with $S\to b\bar{b}$. The interest in this excess re-emerged with the di-photon signature at $\approx$\,95\,GeV at the Large Hadron Collider. In fact, a combined global significance of $3.4\sigma$ is obtained once $WW$ and $\tau \tau$ signals are included in addition. In this article, we perform a feasibility study for discovering such a new scalar $S$ at future electron-positron colliders using the recoil-mass method applied to $e^{+}{e}^{-}\to ZS$ with $Z\to {\mu }^{+}{\mu }^{-}$ and $S\to b\bar{b}$. For this, we employ a Deep Neural Network to enhance the separation between the Standard Model background and the signal, reducing the required integrated luminosity necessary for discovery by a factor of two to three. As a result, an $SU(2{)}_L$ singlet Higgs with a mass of $\approx$\,95\,GeV can be observed with more than 5$\sigma$ significance at a 250\,GeV centre-of-mass energy collider with $5{\mathrm{ab}}^{-1}$ integrated luminosity if it has a mixing angle of at least $0.1$ with the Standard Model Higgs, which means that a discovery can be achieved within the whole 95\% confidence-level region preferred by Large Electron Positron excess. Furthermore, including more decay channels such as $S\to \tau \tau$ and $Z\to e^{+}{e}^{-}$ further enhances the discovery potential of future $e^{+}{e}^{-}$ accelerators, like CEPC, CLIC, FCC-ee and ILC.

   hep-phPLB(2025)·8 citations
2. 02*

   Covariant formulation of spinodal decomposition in rapidly expanding quark gluon plasma

   Joseph I. Kapusta🇺🇸 · Mayank Singh🇺🇸 · Thomas Welle🇺🇸

   Quantum Chromodynamics (QCD) is expected to have a first order phase transition between the confined hadron gas and the deconfined quark gluon plasma at high baryon densities. This will result in phase boundary effects in the metastable and unstable regions. It is important to include these effects in phenomenological models of heavy ion collisions to identify experimental signatures of a phase transition. This requires building intuition on phase separation in rapidly expanding fluids. In this work we present the covariant equations of relativistic hydrodynamics with a phase boundary, provide prescriptions to extend the equation of state to metastable and unstable regions, and show the effects of spinodal separation in a Bjorken flow.

   hep-phnucl-thPRC(2024)·7 citations
3. 03*

   Evolution of coupled scalar perturbations through smooth reheating. I. Dissipative regime

   M. Laine🇨🇭 · S. Procacci🇨🇭 · A. Rogelj🇨🇭

   If the inflaton is a heavy scalar field, it may equilibrate slower than some other degrees of freedom, e.g. non-Abelian gauge bosons. In this case, perturbations in the inflaton field and in a thermal plasma coexist from a given moment onwards. We derive a gauge-invariant set of three coupled equations governing the time evolution of such a system. Despite singular coefficients, a reliable numerical solution can be obtained for a long time period, starting from phase oscillations inside the Hubble horizon, and extending until acoustic oscillations in a radiation-dominated universe. Benchmarks are illustrated from a "weak regime", where perturbations have a quantum-mechanical origin but get dissipated by interactions with the plasma. Among applications of our formalism could be inhomogeneity-induced nucleations in post-inflationary phase transitions, and the production of scalar-induced gravitational waves.

   hep-phastro-ph.COJCAP(2024)·10 citations
4. 04*

   Phase Conventions in Hadron Physics from the Perspective of the Quark Model

   Yu Lu🇨🇳 · Hao-Jie Jing🇨🇳 · Jia-Jun Wu🇨🇳

   Convenient and consistent phase convention is important in the construction of the hadronic Lagrangian. However, the importance of phase convention has been overlooked for a long time and the sources of different conventions are never explicitly addressed. This obscure situation can cause mistakes and misinterpretations in hadron physics. In this paper, we systematically analyze and compare the flavor $S{U}_3$ phase conventions from the perspective of the quark model. All sources which could lead to different conventions are pointed out and carefully studied. With the tool of the quark model, we also clarify some misconceptions and demonstrate a consistent way to incorporate different conventions.

   hep-phSymmetry(2024)·5 citations
5. 05*

   The case for adopting the sequential Jacobi's diagonalization algorithm in neutrino oscillation physics

   Gustavo A. Valdiviesso🇧🇷

   Neutrino flavor oscillations and conversion in an interacting background (MSW effects) may reveal the charge-parity violation in the next generation of neutrino experiments. The usual approach for studying these effects is to numerically integrate the Schrodinger equation, recovering the neutrino mixing matrix and its parameters from the solution. This work suggests using the classical Jacobi's diagonalization in combination with a reordering procedure to produce a new algorithm, the Sequential Jacobi Diagonalization. This strategy separates linear algebra operations from numerical integration, allowing physicists to study how the oscillation parameters are affected by adiabatic MSW effects in a more efficient way. The mixing matrices at every point of a given parameter space can be stored for speeding up other calculations, such as model fitting and Monte Carlo productions. This approach has two major computation advantages, namely: being trivially parallelizable, making it a suitable choice for concurrent computation, and allowing for quasi-model-independent solutions that simplify Beyond Standard Model searches.

   hep-phphysics.comp-phSymmetry(2024)·0 citations
6. 06*

   Multi-Field Effects on Scalar Production in Stars

   Yasuhiro Yamamoto🇹🇼 · Koichi Yoshioka🇯🇵

   This paper studies the dynamics of scalar particle production, focusing on the presence of multiple fields and couplings in the medium. The interplay of various fields and couplings can influence the production rate, potentially overshadowing the effect of electrons alone. The plasma mixing, which induces the resonance and screening of scalar processes, is shown to be modified by the in-medium effects depending on the type of processes and field contents. Incorporating these in-medium effects into the analysis of stellar cooling via scalar emission allows for the emergence of various features of multi-field effects given in several types of scalar models.

   hep-phPRD(2025)·0 citations
7. 07*

   Exploring new physics with DUNE high energy flux: the case of Lorentz Invariance Violation, Large Extra Dimensions and Long Range Forces

   Alessio Giarnetti🇮🇹 · Simone Marciano🇮🇹 · Davide Meloni🇮🇹

   DUNE is a next-generation long-baseline neutrino oscillation experiment. It is expected to measure with an unprecedent precision the atmospheric oscillation parameters, including the CP-violating phase ${\delta }_{CP}$. Moreover, several studies have suggested that its unique features should allow DUNE to probe several new physics scenarios. In this work, we explore the performances of the DUNE far detector in constraining new physics if a high-energy neutrino flux is employed (HE-DUNE). We take into account three different scenarios: Lorentz Invariance Violation (LIV), Long Range Forces (LRF) and Large Extra Dimensions (LED). Our results show that HE-DUNE should be able to set bounds competitive to the current ones and, in particular, it can outperform the standard DUNE capabilities in constraining CPT-even LIV parameters and the compactification radius $R_{ED}$ of the LED model.

   hep-phUniverse(2024)·11 citations
8. 08*

   Three-loop contributions to $b\to s\gamma$ associated with the current-current operators

   Christoph Greub🇨🇭 · Hrachia M. Asatrian🇦🇲 · Hrachya H. Asatryan🇦🇲 · Lukas Born🇨🇭 · Julian Eicher🇨🇭

   In a recent work, we calculated all three-loop diagrams contributing to the decay amplitude for $b\to s\gamma$ where none of the gluons touch the $b$-leg. In the present paper, we complete the calculation by working out all remaining three-loop diagrams (of order ${\alpha }_s^2$) associated with the current-current operators $O_1$ and $O_2$ at the physical value of the charm-quark mass $m_c$. Using the programs AMFlow and DiffExp to solve the differential equations for the master integrals, we obtained precise numerical results at 23 values for $z=m_c^2/m_b^2$, ranging from $z=1/1000$ to $z=1/5$, along with asymptotic expansions around $z=0$. For certain diagrams, the asymptotic expansion breaks down in the physical $z$-range, necessitating a Taylor expansion (which we do around $z=1/10$). In all expansions, we retained power terms up to $z^{20}$ and included the accompanying $\log (z)$ terms to all powers for asymptotic expansions. Numerical results for the sum of all diagrams (including those calculated in the previous paper) are presented in tabular form, while the mentioned expansions of individual diagram classes are provided electronically. We note that our results for the asymptotic expansions around $z=0$ are in good agreement with those recently published by Fael et al. and Czaja et al..

   hep-phJHEP(2024)·8 citations
9. 09*

   Charting Standard Model Duality and its Signatures

   Giacomo Cacciapaglia🇫🇷 · Francesco Sannino🇮🇹

   We investigate high and low energy implications of a gauge dual description of the Standard Model. The high energy electric theory features gauge dynamics involving only fermionic matter fields, while the low energy magnetic description features a quasi-supersymmetric spectrum testable at colliders. The flavour theory is constructed via operators generated at the Planck scale. We further show that duality opens novel avenues for theories of grand unification.

   hep-phhep-lathep-thPRD(2025)·4 citations
10. 10*

    $\tau$-lepton pair spin in proton-proton LHC collisions for anomalous dipole moments

    A.Yu. Korchin🇺🇦 · E. Richter-Was🇵🇱 · Yu. Volkotrub🇵🇱 · Z. Was🇵🇱

    The spin correlations in the pair of $\tau$ leptons produced in the high-energy proton-proton collisions are studied. The invariant mass of the $\tau$-lepton pair is chosen close to $Z$-boson mass, in these conditions $Z$-boson exchange gives the dominant contribution to the Drell-Yan mechanism. The interaction of $Z$ boson with $\tau$ lepton, in addition to the Standard Model couplings, can include weak anomalous magnetic and electric dipole moments (or form-factors) of the $\tau$ lepton. Dependence of elements of the $pp$ spin-correlation matrix on the weak anomalous moments is determined for various regions of the rapidity of the $\tau$-lepton pair. Based on this calculation, we construct a semi-realistic observable built on the momenta of pions in the ${\tau }^{\mp }\to {\pi }^{\mp }{\nu }_{\tau }$ and ${\tau }^{\pm }\to {\rho }^{\pm }{\nu }_{\tau }\to {\pi }^{\pm }{\pi }^0{\nu }_{\tau }$ decay channels, and show that this observable can be sensitive to the weak anomalous dipole moments.

    hep-phPRD(2025)·2 citations
11. 11*

    Studying the heavy quark spin symmetry multiplet of hadronic molecules ${\bar{D}}^{(\ast )}{\Sigma }_c^{(\ast )}$ in the three-body decays of ${\bar{D}}^{(\ast )}{\Lambda }_c\pi$

    Ming-Zhu Liu🇨🇳 · Ya-Wen Pan🇨🇳 · Li-Sheng Geng🇨🇳

    The decay behavior of an exotic state can be used to probe its internal structure. We note that the hidden-charm pentaquark states, $P_{\psi }^N(4312)$, $P_{\psi }^N(4440)$, and $P_{\psi }^N(4457)$, have only been observed in the $J/\psi p$ channel. In this work, we employ the effective Lagrangian approach to systematically investigate the two-body and three-body decays of the heavy quark spin symmetry multiplet of hadronic molecules ${\bar{D}}^{(\ast )}{\Sigma }_c^{(\ast )}$. Our results show that the partial decay widths of the hidden-charm pentaquark molecules into ${\bar{D}}^{(\ast )}{\Lambda }_c\pi$ are sizable so that ${\bar{D}}^{(\ast )}{\Lambda }_c\pi$ are promising channels to search for them, which can help clarify their molecular nature.

    hep-phPRD(2024)·6 citations
12. 12*

    Far-from-equilibrium attractors in kinetic theory for a mixture of quark and gluon fluids

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

    We exactly solve an RTA-Boltzmann equation that describes the dynamics of coupled massless quark and gluon fluids undergoing transversally homogeneous longitudinal boost-invariant expansion. We include a fugacity parameter that allows quarks to be out of chemical equilibrium and we account for the different collision rates of quarks and gluons, which are related by Casimir scaling. Based on these assumptions, we numerically determine the evolution of a large set of moments of the quark and gluon distribution functions and reconstruct their entire distribution functions. We find that both late and early-time attractors exist for all moments of the distribution functions containing more than one power of the squared longitudinal momentum. These attractors emerge long before the system reaches the regime where hydrodynamic approximations apply. In addition, we discuss how the shear viscous corrections and entropy density of the fluid mixture evolve and consider the properties of their respective attractors. Finally, the entropy production is also investigated for different initial values of momentum anisotropy and quark abundance.

    hep-phnucl-thNPA(2025)·10 citations
13. 13*

    A soft-hard framework with exact four momentum conservation for small systems

    I. Soudi🇺🇸 · W. Zhao🇺🇸 · A. Majumder🇺🇸 · C. Shen🇺🇸 · J. H. Putschke🇺🇸 · B. Boudreaux🇺🇸 · A. Angerami🇺🇸 · R. Arora🇺🇸 · S. A. Bass🇺🇸 · Y. Chen🇺🇸 · R. Datta🇺🇸 · L. Du🇨🇦 and 41 other authors

    A new framework, called x-scape, for the combined study of both hard and soft transverse momentum sectors in high energy proton-proton ($p$-$p$) and proton-nucleus ($p$-$A$) collisions is set up. A dynamical initial state is set up using the 3d-Glauber model with transverse locations of hotspots within each incoming nucleon. A hard scattering that emanates from two colliding hotspots is carried out using the Pythia generator. Initial state radiation from the incoming hard partons is carried out in a new module called I-matter, which includes the longitudinal location of initial splits. The energy-momentum of both the initial hard partons and their associated beam remnants is removed from the hot spots, depleting the energy-momentum available for the formation of the bulk medium. Outgoing showers are simulated using the matter generator, and results are presented for both cases, allowing for and not allowing for energy loss. First comparisons between this hard-soft model and single inclusive hadron and jet data from $p$-$p$ and minimum bias $p$-$Pb$ collisions are presented. Single hadron spectra in $p$-$p$ are used to carry out a limited (in number of parameters) Bayesian calibration of the model. Fair comparisons with data are indicative of the utility of this new framework. Theoretical studies of the correlation between jet $p_T$ and event activity at mid and forward rapidity are carried out.

    hep-phhep-exhep-thnucl-thPRC(2025)·17 citations
14. 14*

    Chiral-even twist-3 GPDs for the proton in a spectator diquark model

    Chentao Tan🇨🇳 · Zhun Lu🇨🇳

    We investigate the chiral-even twist-3 generalized parton distributions (GPDs) of valence quarks in the proton at nonzero skewness $\xi$, using a spectator model with scalar and axial-vector diquarks. We consider the exponential form factor for the nucleon-quark-diquark vertex and the axial-vector diquark with light-cone transverse polarization. We analyze the dependence of GPDs on the longitudinal momentum fraction $x$ at different $\xi$, and on the square of the transverse momentum transfer ${\Delta }_T^2$ at different $x$. Our numerical results reveal distinct discontinuities in all twist-3 GPDs except $G_1$ and ${\tilde{G}}_1$. By taking the forward limit, we obtain the twist-3 parton distribution function $g_T$, which encodes the transverse spin distribution of quarks. We also compare the kinetic orbital angular momentum and the spin-orbit correlations of quarks defined by the twist-2 and twist-3 GPDs, respectively.

    hep-phPRD(2024)·3 citations
15. 15*

    Baryogenesis and first-order QCD transition with gravitational waves from a large lepton asymmetry

    Fei Gao🇨🇳 · Julia Harz🇩🇪 · Chandan Hati🇪🇸 · Yi Lu🇨🇳 · Isabel M. Oldengott🇧🇪 · Graham White🇬🇧

    A large primordial lepton asymmetry can lead to successful baryogenesis by preventing the restoration of electroweak symmetry at high temperatures, thereby suppressing the sphaleron rate. This asymmetry can also lead to a first-order cosmic QCD transition, accompanied by detectable gravitational wave (GW) signals. By employing next-to-leading order dimensional reduction we determine that the necessary lepton asymmetry is approximately one order of magnitude smaller than previously estimated. Incorporating an updated QCD equation of state that harmonizes lattice and functional QCD outcomes, we pinpoint the range of lepton flavor asymmetries capable of inducing a first-order cosmic QCD transition. To maintain consistency with observational constraints from the Cosmic Microwave Background and Big Bang Nucleosynthesis, achieving the correct baryon asymmetry requires entropy dilution by approximately a factor of ten. However, the first-order QCD transition itself can occur independently of entropy dilution. We propose that the sphaleron freeze-in mechanism can be investigated through forthcoming GW experiments such as $\mu$Ares.

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

    A QCD R-Axion

    James Unwin🇺🇸 · Tom Yildirim🇬🇧

    R-parity can be extended to a continuous global U(1)${}_R$ symmetry. We investigate whether an anomalous U(1)${}_R$ can be identified as the PQ symmetry suitable for solving the strong CP problem within supersymmetric extensions of the Standard Model. In this case, U(1)${}_R$ is broken at some intermediate scale and the QCD axion is the R-axion. Moreover, the R-symmetry can be naturally gauged via the Green-Schwartz mechanism within completions to supergravity, thus evading the axion quality problem. Obstacles to realizing this scenario are highlighted and phenomenologically viable approaches are identified.

    hep-phhep-thPRD(2025)·6 citations
17. 17*

    SU(3) Gauge Symmetry: An Experimental Review of Diffractive Physics in e+p, p+p, p+A, and A+A Collision Systems

    Krista L. Smith🇺🇸

    This review focuses on diffractive physics, which involves the long-range interactions of the strong nuclear force at high energies described by SU(3) gauge symmetry. It is expected that diffractive processes account for nearly 40% of the total cross-section at LHC energies. These processes consist of soft-scale physics where perturbation theory cannot be applied. Although highly successful and often described as a perfect theory, quantum chromodynamics relies heavily on perturbation theory, a model best suited for hard-scale physics. The study of pomerons could help bridge the soft and hard processes and provide a complete description of the theory of the strong interaction across the full momentum spectrum. Here, we will discuss some of the features of diffractive physics, experimental results from SPS, HERA, and the LHC, and where the field could potentially lead. With the recent publication of the odderon discovery in 2021 by the D0 and TOTEM collaborations and the new horizon of physics that lies ahead with the upcoming Electron-Ion Collider at Brookhaven National Laboratory, interest is seemingly piquing in high energy diffractive physics.

    ↳ nucl-exhep-phSymmetry(2024)·0 citations
18. 18*

    The mass effect -- Variations of the electron mass and their impact on cosmology

    Nils Schöneberg🇪🇸 · Léo Vacher🇫🇷

    We summarize and explain the current status of time variations of the electron mass in cosmology, showing that such variations allow for significant easing of the Hubble tension, from the current $\sim 5\sigma$ significance, down to between $3.4\sigma$ and $1.0\sigma$ significance, depending on the precise model and data. Electron mass variations are preferred by Cosmic Microwave Background (CMB) data in combination with the latest results on baryonic acoustic oscillations (BAO) and type Ia supernovae at a level of significance between $2\sigma$ and $3.6\sigma$ depending on the model and the data. This preference for a model involving an electron mass variation is neither tightly constrained from light element abundances generated during big bang nucleosynthesis nor from post-recombination observations using quasars and atomic clocks, though future data is expected to give strong evidence in favor of or against this model.

    ↳ astro-ph.COgr-qchep-phJCAP(2025)·44 citations
19. 19*

    Simulation study of performance of the Very Large Area gamma-ray Space Telescope

    Xu Pan🇨🇳 · Wei Jiang🇨🇳 · Chuan Yue🇨🇳 · Shi-Jun Lei🇨🇳 · Yu-Xin Cui🇨🇳 · Qiang Yuan🇨🇳

    The Very Large Area gamma-ray Space Telescope (VLAST) is a mission concept proposed to detect gamma-ray photons through both the Compton scattering and electron-positron pair production mechanisms, enabling the detection of photons with energies ranging from MeV to TeV. This project aims to conduct a comprehensive survey of the gamma-ray sky from a low Earth orbit using an anti-coincidence detector, a tracker detector that also serves as a low energy calorimeter, and a high energy imaging calorimeter. We developed a Monte Carlo simulation application of the detector with the GEANT4 toolkit to evaluate the instrument performance including the effective area, angular resolution and energy resolution, as well as explored specific optimizations of the detector configuration. Our simulation-based analysis indicates that the VLAST's current design is physically feasible, with an acceptance larger than 10~${\mathrm{m}}^2\mathrm{sr}$ which is four times larger than Fermi-LAT, an energy resolution better than 2\% at 10~GeV, and an angular resolution better than 0.2 degrees at 10~GeV. The VLAST project is expected to make significant contribution to the field of gamma-ray astronomy and to enhance our understanding of the cosmos.

    ↳ astro-ph.IMastro-ph.HEhep-exhep-ph+1Nucl.Sci.Tech.(2024)·23 citations
20. 20*

    Gravitational waves from black hole emission

    Tousif Islam🇺🇸 · Gaurav Khanna🇺🇸 · Steven L. Liebling🇺🇸

    Using adiabatic point-particle black hole perturbation theory, we simulate plausible gravitational wave~(GW) signatures in two exotic scenarios (i) where a small black hole is emitted by a larger one ('black hole emission') and (ii) where a small black hole is emitted by a larger one and subsequently absorbed back ('black hole absorption'). While such scenarios are forbidden in general relativity!(GR), alternative theories (such as certain quantum gravity scenarios obeying the weak gravity conjecture, white holes, and Hawking radiation) may allow them. By leveraging the phenomenology of black hole emission and absorption signals, we introduce straightforward modifications to existing gravitational waveform models to mimic gravitational radiation associated with these exotic events. We anticipate that these (incomplete but) initial simulations, coupled with the adjusted waveform models, will aid in the development of null tests for GR using GWs.

    ↳ gr-qcastro-ph.HEhep-phUniverse(2025)·2 citations
21. 21*

    Large fluctuations and Primordial Black Holes

    Sayantan Choudhury🇮🇳 · M. Sami🇮🇳

    In this paper, we review in detail different mechanisms of generation of large primordial fluctuations and their implications for the production of primordial black holes (PBHs) and scalar-induced secondary gravity waves (SIGW), with the ultimate aim of understanding the impact of loop correction on quantum correlations and the power spectrum. To accomplish the goal, we provide a concise, comprehensive, but in depth review of conceptual and technical details of the standard model of the universe, namely, causal structure and inflation, quantization of primordial perturbations and field theoretic techniques such as "in-in" formalism needed for the estimation of loop correction to the power spectrum. We discuss at length the severe constraints (no-go) on PBH production in single-field inflation imposed by appropriately renormalized quantum loop corrections, computed while maintaining the validity of the perturbation framework and assuming sufficient inflation to address the causality problem. Thereafter, we discuss in detail the efforts to circumvent the no-go result in Galileon inflation, multiple sharp transition (MST)-induced inflation, and stochastic single field inflation using an effective field theoretic (EFT) framework applicable to a variety of models. We provide a thorough analysis of the Dynamical Renormalization Group (DRG) resummation approach, adiabatic and late-time renormalization schemes, and their use in producing solar and sub-solar mass PBHs. Additionally, we give a summary of how scalar-induced gravitational waves (SIGWs) are produced in MST setups and Galileon inflation.Finally, the PBH overproduction issue is thoroughly discussed.

    ↳ gr-qcastro-ph.COhep-phhep-thPhys.Rept.(2025)·53 citations
22. 22*

    The nuclear matter effect on parton distribution functions

    W. Yang🇨🇳 · C. Li🇨🇳

    Parton distribution functions (PDFs) are important quantities in describing nucleon structures. They are universal and process-independent. As a matter of fact, nucleon PDFs are inevitably affected by nuclear matter during nuclear scattering process. In order to study the nuclear PDFs (nPDFs), in this paper, we introduce the nucleon pair PDFs (dPDFs) to describe parton distributions in the nucleon pair which is confined to a nucleus. We first of all construct the nuclear state in terms of the nucleonic states and calculate the operator definition of nPDFs. Neglecting the higher order corrections or multi-nucleon correlations, we find that nPDFs can be written as a sum of two terms which respectively correspond to PDFs and dPDFs. Nucleon pair PDFs which stem from nucleon-nucleon correlation are proportional to common nucleon PDFs but suppressed by a factor. Compared with the experimental data, we find that dPDFs can explain the behaviour of the EMC effect. We further calculate the Paschos-Wolfenstein ratio to study the nuclear matter effect on the extraction of weak mixing angle or ${\sin }^2{\theta }_W$ by using dPDFs.

    ↳ nucl-thhep-phNPA(2025)·1 citation
23. 23*

    Revealing Hidden Regions in Wide-Angle and Forward Scattering

    Einan Gardi🇬🇧 · Franz Herzog🇬🇧 · Stephen Jones🇬🇧 · Yao Ma🇨🇭

    We discuss a class of Feynman Integrals containing hidden regions that are not straightforwardly identified using the geometric, or Newton polytope, approach to the method of regions. Using Landau singularity analysis and existing analytic results, we study the appearance of such regions in wide-angle and forward scattering and discuss how they can be exposed in both the momentum and parametric representations. We demonstrate that in the strict on-shell limit such integrals contain Landau singularities that prevent their direct numerical evaluation in parameter space and describe how they can be re-parameterised and dissected to circumvent this problem.

    ↳ hep-thhep-phPoS(2024)·4 citations
24. 24*

    Fermi acceleration under Lorentz invariance violation

    Matheus Duarte🇧🇷 · Vitor de Souza🇧🇷

    In this paper, the acceleration of particles in astrophysical sources by the Fermi mechanism is revisited under the assumption of Lorentz invariance violation (LIV). We calculate the energy spectrum and the acceleration time of particles leaving the source as a function of the energy beyond which the Lorentz invariance violation becomes relevant. Lorentz invariance violation causes significant changes in the acceleration of particles by the first and second-order Fermi mechanisms. The energy spectrum of particles accelerated by first-order Fermi mechanism under LIV assumption shows a strong suppression for energies above the break. The calculations presented here complete the scenario for LIV searches with astroparticles by showing, for the first time, how the benchmark acceleration mechanisms (Fermi) are modified under LIV assumption.

    ↳ astro-ph.HEhep-phJCAP(2024)·5 citations
25. 25*

    Impact parameter dependence of anisotropic flow: Bayesian reconstruction in ultracentral nucleus-nucleus collisions

    Mubarak Alqahtani🇸🇦 · Rajeev S. Bhalerao🇮🇳 · Giuliano Giacalone🇨🇭 · Andreas Kirchner🇩🇪 · Jean-Yves Ollitrault🇫🇷

    Peculiar phenomena have been observed in analyses of anisotropic flow ($v_n$) fluctuations in ultracentral nucleus-nucleus collisions: The fourth-order cumulant of the elliptic flow ($v_2$) distribution changes sign. In addition, the ATLAS collaboration has shown that cumulants of $v_n$ fluctuations of all orders depend significantly on the centrality estimator. We show that these peculiarities are due to the fact that the impact parameter $b$ always spans a finite range for a fixed value of the centrality estimator. We provide a quantitative determination of this range through a simple Bayesian analysis. We obtain excellent fits of STAR and ATLAS data, with a few parameters, by assuming that the probability distribution of $v_n$ solely depends on $b$ at a given centrality. This probability distribution is almost Gaussian, and its parameters depend smoothly on $b$, in a way that is constrained by symmetry and scaling laws. We reconstruct, thus, the impact parameter dependence of the mean elliptic flow in the reaction plane in a model-independent manner, and assess the robustness of the extraction using Monte Carlo simulations of the collisions where the impact parameter is known. We argue that the non-Gaussianity of $v_n$ fluctuations gives direct information on the hydrodynamic response to initial anisotropies, ATLAS data being consistent with a smaller response for $n=4$ than for $n=2$ and $n=3$, in agreement with hydrodynamic calculations.

    ↳ nucl-thhep-exhep-phnucl-exPRC(2024)·8 citations
26. 26*

    Probing collectivity in heavy-ion collisions with fluctuations of the $p_T$ spectrum

    Tribhuban Parida🇮🇳 · Rupam Samanta🇵🇱 · Jean-Yves Ollitrault🇫🇷

    Event-by-event fluctuations in the initial stages of ultrarelativistic nucleus-nucleus collisions depend little on rapidity. The hydrodynamic expansion which occurs in later stages then gives rise to correlations among outgoing particles which depend weakly on their relative rapidity. Azimuthal correlations, through which anisotropic flow ($v_n(p_T)$) is defined, have been the most studied. Here we study a new observable introduced in 2020 by Schenke, Shen and Teaney and dubbed $v_0(p_T)$, which quantifies the relative change in the $p_T$ spectrum induced by a fluctuation. We describe how it can be measured. Using hydrodynamic simulations, we make quantitative predictions for $v_0(p_T)$ of charged and identified hadrons. We then discuss how $v_0(p_T)$ relates to two phenomena which have been measured: The increase of the mean transverse momentum in ultracentral collisions, and the event-by-event fluctuations of the transverse momentum per particle $[p_T]$. We show that $v_0(p_T)$ determines the dependence of these quantities on the $p_T$ cuts implemented in the analysis. We quantitatively explain the rise of ${\sigma }_{p_T}$ observed by ATLAS as the upper $p_T$-cut is increased from $2$ to $5$~GeV/$c$.

    ↳ nucl-thhep-exhep-phnucl-exPLB(2024)·38 citations
27. 27*

    State preparation of lattice field theories using quantum optimal control

    Jack Y. Araz🇺🇸 · Siddhanth Bhowmick🇮🇳 · Matt Grau🇺🇸 · Thomas J. McEntire🇺🇸 · Felix Ringer🇺🇸

    We explore the application of quantum optimal control (QOC) techniques to state preparation of lattice field theories on quantum computers. As a first example, we focus on the Schwinger model, quantum electrodynamics in 1+1 dimensions. We demonstrate that QOC can significantly speed up the ground state preparation compared to gate-based methods, even for models with long-range interactions. Using classical simulations, we explore the dependence on the inter-qubit coupling strength and the device connectivity, and we study the optimization in the presence of noise. While our simulations indicate potential speedups, the results strongly depend on the device specifications. In addition, we perform exploratory studies on the preparation of thermal states. Our results motivate further studies of QOC techniques in the context of quantum simulations for fundamental physics.

    ↳ quant-phhep-lathep-phPRD(2025)·12 citations
28. 28*

    Observability of dynamical tides in merging eccentric neutron star binaries

    János Takátsy🇭🇺 · Bence Kocsis🇬🇧 · Péter Kovács🇭🇺

    While dynamical tides only become relevant during the last couple of orbits for circular inspirals, orbital eccentricity can increase their impact during earlier phases of the inspiral by exciting tidal oscillations at each close encounter. We investigate the effect of dynamical tides on the orbital evolution of eccentric neutron star binaries using post-Newtonian numerical simulations and construct an analytic stochastic model that reproduces the numerical results. Our study reveals a strong dependence of dynamical tides on the pericenter distance, with the fractional energy transferred to dynamical tides over that dissipated in gravitational waves (GWs) exceeding $\sim 1\%$ at separations $r_{\mathrm{p}}\lesssim 50$ km for large eccentricities. We demonstrate that the effect of dynamical tides on orbital evolution can manifest as a phase shift in the GW signal. We show that the signal-to-noise ratio of the GW phase shift can reach the detectability threshold of $8$ with a single aLIGO detector at design densitivity for eccentric neutron star binaries at a distance of $40$ Mpc. This requires a pericenter distance of $r_{p0}\lesssim 68$ km ($r_{p0}\lesssim 76$ km) at binary formation with eccentricity close to $1$ for a reasonable tidal deformability and f-mode frequency of $500$ and $1.73$ kHz ($700$ and $1.61$ kHz), respectively. The observation of the phase shift will enable measuring the f-mode frequency of neutron stars independently from their tidal deformability, providing significant insights into neutron star seismology and the properties of the equation of state. We also explore the potential of distinguishing between equal-radius and twin-star binaries, which could provide an opportunity to reveal strong first-order phase transitions in the nuclear equation of state.

    ↳ astro-ph.HEhep-phnucl-thPRD(2024)·7 citations
29. 29*

    Fermion-Vortex Interactions in Axion Electrodynamics

    Saurav Kantha🇮🇳 · Amitabha Lahiri🇮🇳

    A relativistic action for scalar condensate-fermion mixture is considered where both the scalar boson and the fermion fields are coupled to a $U(1)$ gauge field. The dynamics of the gauge field is governed by a linear combination of the Maxwell term, and the Lorentz invariant $\mathbf{E}\cdot \mathbf{B}$ term with a constant coefficient $\theta$. We obtain an effective action describing an emergent fermion-fermion interaction and fermion-vortex tube interaction by using the particle-string duality, and find that the $\theta$ term can significantly affect the interaction of fermions and vortices. We also perform a dimensional reduction to show a $\theta$ dependent flux attachment to the itinerant fermions.

    ↳ cond-mat.supr-conhep-phhep-thAnnals Phys.(2025)·0 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.