Mon·Mar 9, 2026Monday·March 9, 2026

1. 01*

   Temperature dependence on Spectrum of Heavy Hybrid Mesons

   Ali Zeeshan🇵🇰 · Nosheen Akbar🇵🇰 · Sadia Arshad🇵🇰 · Ali Akgul🇹🇷

   In this work, temperature dependence on the masses of conventional and hybrid heavy quarkonium systems is investigated. For this, a thermally screened interaction is incorporated through Debye mass $(m_D(T))$ into the potential models of conventional and hybrid charmonium ($c\overline{c}$) and bottomonium ($b\overline{b}$) mesons (conventional and hybrid). Mass eigenvalues for S, P, D states of these mesons are computed by power series expansion method at different values of debye mass. Comparison with available lattice-QCD-inspired potentials and previous numerical studies show strong agreement and validate the efficiency of power-series technique for calculations of mass of heavy quarkonium at finite-temperature. Our results can be helpful to explore the recent experimentally determined states of charmonium and bottomonium.

   hep-ph0 citations
2. 02*

   Vacuum Cherenkov Radiation for Nonminimal Isotropic Lorentz Violation

   Albert Yu. Petrov🇧🇷 · Marco Schreck🇧🇷 · Alexandre R. Vieira🇧🇷

   In this work, we study the effects of vacuum Cherenkov radiation caused by nonminimal dimension-5 Lorentz-violating (LV) operators in the fermion sector. Explicitly, we focus on two independent isotropic pieces of each set of nonminimal coefficients. Under the assumption that vacuum Cherenkov radiation is an expected phenomenon, experimental data of ultra-high-energy cosmic rays (UHECRs) allow us to put stringent bounds on isotropic coefficients in quarks.

   hep-phhep-thProceedings of Tenth Meeting on CPT and L…·0 citations
3. 03*

   Recent progress in antenna subtraction at NNLO and N${}^3$LO

   Matteo Marcoli🇬🇧

   In this contribution I will review recent developments in the antenna subtraction method for higher-order calculations in QCD. In particular, I will illustrate the definition and applications of generalised antenna functions for final-state radiation at NNLO and present the first N${}^3$LO differential calculation performed entirely with antenna subtraction for jet production at electron-positron colliders. Finally, I will discuss how the extension of generalised antenna functions at N${}^3$LO will allow to tackle more complicated processes at this perturbative order.

   hep-ph0 citations
4. 04*

   Entanglement measures and Bell-type spin-correlation observables in tau-lepton pairs at the Super Tau-Charm Facility

   Beizhi Yang · Yu Zhang🇨🇳 · Zeren Simon Wang🇨🇳 · Xiaorong Zhou🇨🇳

   Within the framework of quantum field theory and the Standard Model (SM), we investigate the prospects of studying entanglement measures and Bell-type spin-correlation observables in the electroweak process $e^{-}{e}^{+}\to {\tau }^{-}{\tau }^{+}$ at the center-of-mass (COM) energies of $\sqrt{s}=3.670,4.630$, and $7.000$ GeV at the proposed Super Tau-Charm Facility (STCF) in China. Focusing on the hadronic decay channel ${\tau }^{\pm }\to {\pi }^{\pm }\nu$, we determine the spin-correlation coefficients of the ${\tau }^{-}{\tau }^{+}$ system within the SM framework using measurable production kinematics, namely the $\tau$ velocities and scattering angles in the COM frame. From these correlation coefficients, we construct concurrence and a Bell-type correlation combination as defined in the literature. Assuming an integrated luminosity of 1 ab${}^{-1}$ for each considered COM energy, and incorporating realistic detector efficiencies as well as statistical and systematic uncertainties, we estimate the expected sensitivity to these observables at STCF. Our results indicate that, under the SM hypothesis, the corresponding Bell-type correlation combinations could be resolved with high statistical significance at STCF.

   hep-phhep-ex10 citations
5. 05*

   Two Higgs Doublet Model from Six Dimensional Gauge Theory

   Kento Akamatsu🇯🇵 · Takuya Hirose🇯🇵 · Nobuhito Maru🇯🇵 · Akio Nago🇯🇵

   We improve our previously proposed two Higgs doublet model of six-dimensional $SU(4)$ gauge theory compactified on an orbifold $T^2/Z_2$ by introducing the brane localized gauge kinetic terms. Since two Higgs doublets are identified with massless zero modes in extra spatial components of the six-dimensional gauge field, the Higgs sector in our model is constrained by the six-dimensional gauge symmetry. As a result, our Higgs potential at tree-level is automatically CP conserving and $Z_2$ symmetric, which are assumed by hand in the ordinary two Higgs doublet models. The scalar masses breaking the $Z_2$ symmetry softly are generated at one-loop. We show that the Standard Model Higgs mass can be obtained by tuning the size of the brane localized gauge kinetic terms as well as the electroweak symmetry breaking is realized. Other physical Higgs masses are predicted.

   hep-phhep-th2 citations
6. 06*

   The effects of Higgs boson couplings through HZZ production at future lepton colliders

   Serdar Spor🇹🇷

   We focus on the sensitivity of the anomalous Higgs-gauge boson couplings at $H\gamma Z$ and $HZZ$ vertices through the process ${\ell }^{-}{\ell }^{+}\to HZZ$ at CLIC and Muon Collider. Signal and relevant backgrounds events are generated in MadGraph within Standard Model Effective Field Theory (SMEFT) framework. These events are passed through Pythia for parton showering, and realistic detector effects are simulated by Delphes. The limits at 95% C.L. on the coefficients ${\overline{c}}_{HB}$ and ${\overline{c}}_{HW}$ are obtained at two b-tagging working points; loose and medium containing the Delphes card from CLIC and Muon Collider, corresponding to b-tagging efficiencies of 90% and 70%, respectively. We report that our best 95% C.L. limits on ${\overline{c}}_{HB}$ and ${\overline{c}}_{HW}$ coefficients are $[-0.00138;0.00090]$ and $[-0.00162;0.00026]$, respectively, at 3 TeV CLIC with an integrated luminosity of 5 ab${}^{-1}$, and $[-0.00024;0.00023]$ and $[-0.00020;0.00009]$, respectively, at 10 TeV Muon Collider with an integrated luminosity of 10 ab${}^{-1}$. These limits are compared with the present experimental and various phenomenological limits.

   hep-phFront.Phys.(2026)·0 citations
7. 07*

   Lattice QCD constraints on pion electroproduction off a nucleon

   Yu Zhuge🇨🇳 · Zhan-Wei Liu🇨🇳 · Derek B. Leinweber🇦🇺 · Anthony W. Thomas🇦🇺

   Very recently, a lattice QCD collaboration has explored threshold pion electroproduction near the physical pion mass and has simulated the relevant multipole amplitudes. Different multipole amplitudes are usually entangled in experimental data, and thus extracting each of them independently from first principles provides additional essential constraints on phenomenological theories. We use nonperturbative Hamiltonian theory to investigate the electroproduction process, providing an advanced approach with additional two-particle coupled channels to acquire the physical electric dipole amplitudes from the original lattice QCD data. We note that future lattice QCD simulations of the electric dipole amplitudes at higher energies will be much closer to their physical counterparts than the current ones near threshold. In addition, we obtain a new expression which, like that of Lellouch-Lüscher, depends only on the final-state interactions but provides both the real and imaginary parts of the transition amplitudes.

   hep-phhep-latnucl-th0 citations
8. 08*

   On Thrust Resummation Ambiguities in $e^{+}{e}^{-}$ Annihilation into Hadrons

   Luca Buonocore🇨🇭 · Paolo Nason🇮🇹 · Luca Rottoli🇮🇹 · Paolo Torrielli🇮🇹

   In $e^{+}{e}^{-}$ shape-variable studies, and in particular for the case of thrust, fixed-order QCD predictions are typically supplemented with the resummation of contributions enhanced near the two-jet limit. In this work we examine whether different, yet legitimate, resummation prescriptions can induce significant differences in the resulting predictions. This can occur because formally equivalent prescriptions may differ by terms that, although subleading, are characterised by asymptotic expansions and may therefore lead to slow convergence. We first compare two alternative formulations of resummation: the conjugate-space (or Laplace-space) approach, in which resummation is performed in a variable conjugate to thrust, such that the observable factorises exactly in the soft-collinear limit; and the direct-space formulation, where resummation is instead carried out directly in the thrust variable. We show that, at double-logarithmic level, the inverse Laplace transform generates a convergent tower of subleading terms. Starting from leading-logarithmic accuracy, the expansion becomes asymptotic due to the presence of the Landau pole, leading to a mild log-factorial growth of the coefficients. When including the highest available logarithmic order in the resummation, matched to fixed-order results, we still find non-negligible differences between predictions obtained in the two spaces. We then consider a formulation of the resummation that avoids certain approximations commonly used in the derivation of conjugate-space resummation. We observe that this also has a non-negligible numerical impact. In general, we find that the systematics stemming from the adoption of different formalisms typically exceeds the quoted theoretical uncertainties, suggesting the need for more conservative theory-error estimates when using the thrust distribution in determinations of the strong coupling.

   hep-phhep-ex2 citations
9. 09*

   Generalized transverse momentum distributions at small-$x$

   Sanjin Benić🇭🇷 · Yoshikazu Hagiwara🇭🇷 · Boris Šarić🇭🇷 · Eric Andreas Vivoda🇭🇷

   We compute the complete set of the leading-twist gluon and sea-quark generalized transverse momentum distributions (GTMDs) in the small-$x$, or eikonal, approximation at vanishing skewness $\xi =0$. All the gluon GTMDs become expressed in terms of the basic gluon dipole operator featuring also proton helicity-flips. Consequently, we establish universal relations between otherwise distinct GTMDs that hold in the small-$x$ limit. The obtained results are systematically projected onto the transverse momentum dependent distributions (TMD) and the generalized parton distribution (GPD) cases, recovering known results where available. In case of sea-quarks all the GTMDs are given in terms of the gluon dipole convoluted with a hard kernel. We generalize the unpolarized sea-quark GTMD to non-zero momentum transfers and find new results for the proton helicity-flip distributions. We pay special attention to their perturbative, high transverse momentum, tails to confirm that it becomes governed by the small-$x$ gluon GPDs. The obtained results provide guidance to the phenomenological modeling of the GTMDs but also allow for their explicit computations.

   hep-ph6 citations
10. 10*

    Next-to-next-to-leading order event generation for $t\bar{t}H$ production with approximate two-loop amplitude

    Christian Biello🇨🇭 · Chiara Savoini🇩🇪 · Chiara Signorile-Signorile🇨🇭 · Marius Wiesemann🇩🇪

    We study Higgs-boson production in association with a top-quark pair ($t\bar{t}H$) at hadron colliders and present the first matching of next-to-next-to-leading order (NNLO) QCD corrections to parton showers using the MiNNLOPS method. For the two-loop amplitude, we employ two established approximations, based on the soft Higgs-boson and high-energy limits, respectively. For the first time, we also construct the latter in full colour and propose a pointwise combination of the two approximations across phase space. By assigning a conservative uncertainty estimate, which remains well below the perturbative uncertainties, we ensure robust and reliable differential predictions, explicitly validated at the one-loop level. Apart from the two-loop amplitude, all remaining ingredients of the MiNNLOPS calculation are included exactly. After thorough validation, we present a series of phenomenological results illustrating the impact of NNLO corrections and parton-shower effects. We consider fiducial predictions for the Higgs-boson decay into photons and include off-shell top-quark decays with tree-level spin correlations in both the dilepton and semileptonic channels. Our $t\bar{t}H$ MiNNLOPS generator is publicly available within the POWHEG framework.

    hep-phhep-exJHEP(2026)·3 citations
11. 11*

    Threshold resummation for gluon fusion $ZH$ production at the LHC

    Goutam Das🇩🇪 · Chinmoy Dey🇮🇳 · M. C. Kumar🇮🇳 · Kajal Samanta🇬🇧

    We present precise results for the $ZH$ production cross-section and invariant mass distribution at the LHC, taking into account the effects of the leading and sub-leading soft gluons. We improve both quark-initiated and gluon-initiated subprocesses through threshold resummation within the QCD framework.

    hep-ph0 citations
12. 12*

    The Higgs boson in the CP-violating NB-LSSM

    Xing-Xing Dong🇨🇳 · Wen-Hui Zhang🇨🇳 · Cai Guo🇨🇳 · Shu-Min Zhao🇨🇳 · Tai-Fu Feng🇨🇳

    This study investigates the lightest and second-lightest Higgs bosons at around 95 GeV (which is only a hypothetical scenario) and 125 GeV respectively within the CP-violating next to minimum B-L supersymmetric model(NB-LSSM). In the NB-LSSM, the CP violation in the Higgs potential leads to the mixing mass terms between the CP-even and CP-odd Higgs fields. Thus, one has to consider a $(10\times 10)$-dimensional mass matrix for the neutral Higgs boson. These potential mixing effects may lead to drastic variations on the neutral Higgs boson masses. Besides, the neutral Higgs bosons predicted in the NB-LSSM may strongly mix with one another, thereby significantly modifying the couplings of the Higgs bosons to the fermions or gauge bosons. It is found that the specific parameters $g_{YB}$, $\tan \beta$, $T_{\kappa }$, $T_{\lambda },\cdot \cdot \cdot$ and CP-violating phases ${\theta }_{1,2,3,4,6,7,8}$ in the NB-LSSM affect the theoretical predictions on the Higgs boson mass and corresponding signal strengthes significantly. And the theoretical predictions on the signal strengthes of SM-like Higgs decay channels and excess signals at around 95 GeV are fitted well to the observed experimental data.

    hep-phEPJC(2026)·0 citations
13. 13*

    Threshold Resummation of Drell-Yan type colorless processes at LHC

    Goutam Das🇩🇪 · Chinmoy Dey🇮🇳 · M C Kumar🇮🇳 · Kajal Samanta🇬🇧

    We look at the threshold effects in neutral and charged Drell-Yan production, Higgs boson production with a massive vector boson, and Higgs production in bottom quark annihilation at the Large Hadron Collider (LHC), up to the third order in QCD. Using third-order soft-virtual (SV) results and the universal properties of threshold logarithms, we find the process-dependent coefficients and improve the accuracy by including large threshold logarithms up to next-to-next-to-next-to-leading logarithmic (N${}^3$LL) order and matched with the latest N${}^3$LO results. We also show numerical results for the invariant mass distributions and total production cross sections for these processes. Our findings show that the theoretical scale uncertainties, which are about $0.4\%$ at N${}^3$LO in fixed-order calculations, decrease to less than $0.1\%$ at N${}^3$LO+N${}^3$LL after SV threshold resummation in the high invariant mass region.

    hep-ph0 citations
14. 14*

    Revisiting unitarity of single scalar field with non-minimal coupling

    Minxi He🇰🇷 · Muzi Hong🇯🇵 · Kyohei Mukaida🇯🇵 · Tomoya Nishiki

    We have investigated the unitarity violation scale of a non-minimally coupled scalar field with quartic self-coupling. This model is widely studied in the literature but the estimation of the unitarity violation scale has not been consistently discussed, especially in the Jordan frame. We have calculated the six-point scattering amplitudes of the scalar particles in both the Jordan frame and the Einstein frame, and explicitly shown the frame-independence of the results. Since the extended target space with the conformal mode is trivial in the single-field case, the dominant contribution comes from the potential of the scalar field. The results in both frames become trivial in the vanishing self-coupling limit as expected.

    hep-phastro-ph.COhep-th0 citations
15. 15*

    QCD corrections for Pseudoscalar Higgs decay to 3 partons at higher orders in dimensional regulator

    Pulak Banerjee🇮🇹 · Chinmoy Dey🇮🇳 · M.C. Kumar🇮🇳 · V. Ravindran🇮🇳

    In this contribution, we present our recent study on the second-order corrections of pseudo-scalar($A$) Higgs decay to three partons, at higher orders in the dimensional regulator. We have studied the one and two-loop amplitudes for processes, $A\to ggg$ and $A\to q\bar{q}g$ in the effective theory framework. Our results, after suitable crossings of the external momenta, are important ingredients for predicting the differential distribution of the pseudo-scalar Higgs boson in association with a jet at hadron colliders.

    hep-ph0 citations
16. 16*

    VV Resummation To NNLO+NNLL At the LHC

    Pulak Banerjee🇮🇹 · Chinmoy Dey🇮🇳 · M. C. Kumar🇮🇳 · Vaibhav Pandey🇮🇳

    We present the resummed predictions for a vector boson pair production at the LHC. We have performed threshold resummation to next-to-next-to-leading logarithmic (NNLL) accuracy, and then matched them to next-to-next-to-leading order (NNLO) QCD results. After resummation, we observe a reduction in the scale uncertainties arising from unphysical renormalization and factorization scales. We find that the resummed corrections add a few per cent to the fixed order results for both ZZ and WW production.

    hep-ph0 citations
17. 17*

    Phenomenology of Matching Exponentiated Photonic Radiation to a Parton Shower in KKMChh

    Scott A. Yost🇺🇸 · B.F.L. Ward🇺🇸 · Zbigniew Was🇵🇱

    KKMChh adapts the soft photon exponentiation of the program KKMC, initially for electron-positron annihilation, to hadron collisions, where it must interface to a parton shower and parton distribution functions (PDFs) which may already include effects of QED radiation. We describe the NISR (Negative Initial State Radiation) algorithm developed to consistently interface with PDFs including QED effects, and present results on its effect on some distributions of phenomenological interest.

    hep-ph0 citations
18. 18*

    Recursive reduction of two-loop tensor integrals

    Fabian Lange🇨🇭 · Max F. Zoller🇨🇭

    In order to meet the precision requirements for the LHC and future colliders, next-to-next-to-leading order corrections to a wide range of processes are essential, making general automated tools highly desirable. Extending the strategy of the widespread one-loop program OpenLoops to two loops, there are three major ingredients: process-dependent tensor coefficients, tensor integrals, and process-independent counterterms. In these proceedings, we focus on the second part and present a new recursive algorithm to reduce arbitrary two-loop tensor integrals to scalar integrals numerically.

    hep-ph1 citation
19. 19*

    Third-order mixed electroweak-QCD corrections to the W-boson mass prediction from the muon lifetime

    Ievgen Dubovyk🇵🇱 · Ayres Freitas🇺🇸 · Janusz Gluza🇵🇱 · Johann Usovitsch🇩🇪

    We present the calculation of the so far missing $\mathcal{O}({\alpha }^2{\alpha }_{\mathrm{s}})$ corrections to the quantity $\Delta r$, which relates the Fermi constant to the W-boson mass, and enables precision predictions of the latter. While the $\mathcal{O}({\alpha }^2{\alpha }_{\mathrm{s}})$ corrections from diagrams with two closed fermion loops are already known, we here focus on the subset with one closed fermion loop, which is a substantially more complex problem. The calculation has been carried out through a combination of analytical and numerical techniques for the three-loop integrals and the on-shell renormalization. The impact of the new corrections is numerically significant, raising the Standard Model prediction for the W-boson mass by more than 3 MeV.

    hep-ph2 citations
20. 20*

    Alternative classical Lagrangians for the Standard-Model Extension

    João A.A.S. Reis🇧🇷 · Marco Schreck🇧🇷 · Ronaldo Thibes🇧🇷

    The current paper introduces classical, relativistic Lagrangians for point-particle analogs to the field theory description of the Standard-Model Extension (SME) for Lorentz violation. Lagrangians of a form alternative to those derived and studied in previous works are in the spotlight. Interestingly, they have well-defined massless limits, which makes them suitable for describing classical-particle analogs of photons subject to Lorentz violation. We first deal with different types of Dirac fermion coefficients, followed by various configurations of the SME photon sector. The Lagrangians are accompanied by constraints that we treat properly using the techniques due to Dirac. The results encountered may find application in photon propagation through gravitational fields in the presence of spacetime symmetry violation. Connections to Finsler geometry are likely to exist.

    hep-phhep-thPRD(2026)·3 citations
21. 21*

    Quantum and Thermal Fluctuations of Cherenkov Radiation from HQET

    Joshua Lin🇺🇸 · Bruno Scheihing-Hitschfeld🇺🇸

    Charged particles travelling faster than the speed of light in the medium in which they propagate emit Cherenkov radiation. The formula for the spectrum of this radiation as a function of frequency, known as the Frank-Tamm formula, first derived almost 90 years ago, follows purely from classical electromagnetism. In this work, we demonstrate how this result also follows from a short quantum field theory calculation, which in addition to it contains all of the cumulants of thermal and quantum fluctuations around the classical radiation spectrum at leading order in the inverse of the particle's mass. All of these results follow from the particle's momentum change probability, which we calculate for weakly coupled gauge theories using the tools of Heavy Quark Effective theory.

    hep-phhep-th0 citations
22. 22*

    The meV frontier of neutrinoless double beta decay in the JUNO era

    J. T. Penedo🇮🇹 · S. T. Petcov🇮🇹

    Observing neutrinoless double beta decay would establish lepton number violation and the Majorana nature of neutrinos. Within the standard 3-flavour paradigm, the rate of this process is controlled by the effective Majorana mass $|⟨m⟩|$, which may be severely suppressed if the neutrino mass spectrum presents normal ordering. Taking into account the first JUNO results, which significantly reduce the uncertainties on solar neutrino oscillation parameters, we provide updated conditions under which $|⟨m⟩{|}_{\text{NO}}$ is guaranteed to exceed the $10^{-3}$ eV ($5\times 10^{-3}$ eV) threshold. We analyse both the generic case, as well as scenarios where the two Majorana phases either take CP conserving values, or at least one of them takes a CP-violating value, that are in line with predictive schemes combining flavour and generalised CP symmetries.

    hep-phPLB(2026)·1 citation
23. 23*

    Dark matter relic abundance from a critical-density instability

    Hindi Zouhair🇲🇦

    We study a nonstandard dark-matter thermal history in which strong self-interactions give rise to collective many-body effects at high number density, as in strongly interacting quantum media. At early times, dark matter occupies a correlated phase in which its coupling to a light mediator is dynamically screened, suppressing annihilation far below the perturbative rate. As the Universe expands and the number density decreases, this screened phase becomes unstable at a critical density n_c, triggering a rapid, far-from-equilibrium annihilation episode. We show that this annihilation burst fixes the final relic abundance, which is governed primarily by n_c rather than by the microscopic annihilation coupling. Using a minimal effective parametrization, we solve the resulting modified Boltzmann evolution and map the viable parameter space. For TeV-scale dark matter and sub-GeV mediators, we find relic abundances consistent with observations together with self-interaction cross sections relevant for small-scale structure, realizing a consistent and predictive nonstandard thermal history.

    hep-ph0 citations
24. 24*

    Pathologies of dimension-zero scalar fields

    James M. Cline🇨🇦 · Anamaria Hell🇯🇵

    It has been claimed in a series of papers that scalar fields with a fourth-order Lagrangian $\sim (\square \phi {)}^2$ can solve the cosmological constant problem by canceling the loop contributions from standard model fields, and that their fluctuations can be the source of the primordial density perturbations of the Universe, without the need for inflation. We dispute these claims. The spectrum of the theory includes a ghost, which leads to classical instabilities and quantum violation of unitarity. We show that the new scalar particles cannot cancel the standard model contributions to the cosmological constant, unless they include a unitarity-violating ghost at the quantum level. Further, the coupling of such scalars to the particles of the standard model induces a confining fifth force which rules it out as a source of density perturbations in the early Universe.

    ↳ hep-thastro-ph.COgr-qchep-phPRD(2026)·1 citation
25. 25*

    Agentic AI -- Physicist Collaboration in Experimental Particle Physics: A Proof-of-Concept Measurement with LEP Open Data

    Anthony Badea · Yi Chen · Marcello Maggi · Yen-Jie Lee · Electron-Positron Alliance

    We present an AI agentic measurement of the thrust distribution in $e^{+}{e}^{-}$ collisions at $\sqrt{s}=91.2$~GeV using archived ALEPH data. The analysis and all note writing is carried out entirely by AI agents (OpenAI Codex and Anthropic Claude) under expert physicist direction. A fully corrected spectrum is obtained via Iterative Bayesian Unfolding and Monte Carlo based corrections. This work represents a step toward a theory-experiment loop in which AI agents assist with experimental measurements and theoretical calculations, and synthesize insights by comparing the results, thereby accelerating the cycle that drives discovery in fundamental physics. Our work suggests that precision physics, leveraging the open LEP data and advanced theoretical landscape, provides an ideal testing ground for developing advanced AI systems for scientific applications.

    ↳ hep-excs.AIhep-ph15 citations
26. 26*

    A Lattice QCD study of $p-\Lambda$ scattering in continuum and chiral limits

    Hang Liu🇨🇳 · Liuming Liu🇨🇳 · Jin-Xin Tan🇨🇳 · Wei Wang🇨🇳 · Haobo Yan🇨🇳 · Qian-Teng Zhu🇨🇳

    We present a first systematic study of $I=1/2$ proton-$\Lambda$ ($p$-$\Lambda$) scattering from lattice QCD, using seven sets of $(2+1)$-flavor lattice ensembles with pion masses spanning 135-317 MeV and three lattice spacings with $a=(0.052,0.077,0.105)$ fm. Using Lüscher's finite-volume method, effective range expansion and chiral/continuum extrapolations, we obtain the inverse of scattering length and effective range for the ${}^1{S}_0$ channel as 0.177(83) GeV and 2.9(1.4) fm, and for the ${}^3{S}_1$ channel as 0.016(76) GeV and 1.8(1.1) fm. From the derived S-wave phase shifts, we provide an estimate of the $p-\Lambda$ scattering cross section. Our results for scattering length, effective range and cross sections are in good agreement with available experimental measurements. We also find that the $p-\Lambda$ system sustains attractive interactions. These results provide critical input for the unification of nuclear force theories and the construction of neutron star equations of state.

    ↳ hep-lathep-exhep-phnucl-ex+12 citations
27. 27*

    Latin American HECAP Physics Briefing Book 2025

    Mario A. Acero (U. del Atlántico - Colombia)🇨🇴 · Alexis A. Aguilar-Arevalo (UNAM - México)🇲🇽 · Belén Andrada (CNEA/CONICET/UNSAM - Argentina)🇦🇷 · Andrés Baquero Larriva (U. del Azuay - Ecuador)🇪🇨 · Mauro Cambiaso (U. Andrés Bello - Chile)🇨🇱 · Edgar Carrera (U. San Francisco de Quito - Ecuador)🇪🇨 · Melissa Cruz (U. Nacional Autónoma de Honduras - Honduras)🇭🇳 · Lucía Duarte (U. de la República - Uruguay)🇺🇾 · Juan Estrada (Brookhaven National Laboratory - USA)🇺🇸 · Alberto Gago (Pontifica U. Católica - Perú)🇵🇪 · Esteban Jimenez (U. de Costa Rica - Costa Rica)🇨🇷 · Diana López Nacir (UBA/CONICET - Argentina)🇦🇷 and 15 other authors

    The first process for the Latin American Strategy Forum for Research Infrastructure for High Energy, Cosmology and Astroparticle Physics (LASF4RI-HECAP) came to a conclusion in October 2020, with a Physics Briefing Book (PBB) presented in (2104.06852). Here we present an updated PBB, the result of the first update of LASF4RI-HECAP. The update process began with a call for White Papers from the HECAP community. The submitted contributions were presented at the III LASF4RI for HECAP Symposium: Update of the Strategic Plan, held at ICTP-SAIFR in São Paulo in August 26-29, 2024, with the participation of the Preparatory Group, High Level Strategy Group, Funding Agencies and representatives of similar efforts from around the globe. This updated PBB was written by the Preparatory Group based mainly on 46 White Papers submitted by the community and is organized around seven working groups: Astronomy, Astrophysics and Astroparticle Physics; Cosmology; Dark Matter; Neutrinos; Electroweak and Strong Interactions, Higgs Physics, CP and Flavour Physics and BSM; Instrumentation and Computing; Advanced Training and Capacity Building. It is intended to provide the essential input for the creation of a long-term HECAP strategy in the region.

    ↳ hep-exastro-ph.COastro-ph.IMhep-ph0 citations
28. 28*

    Survival of ultraheavy nuclei in astrophysical sources: applications to protomagnetar outflows

    Nick Ekanger🇯🇵 · Mukul Bhattacharya🇮🇳 · Kohta Murase🇺🇸 · Shunsaku Horiuchi🇺🇸

    Outflows of rapidly rotating protomagnetars have been considered as attractive sites for the synthesis of nuclei heavier than iron, but the question remains whether these nuclei are able to survive against photodisintegration as they make their way out of their formation environments. In this work, we present new analytic fitting formulae for the photodisintegration cross sections applicable to heavy nuclei beyond iron. We confirm that the results from the TALYS simulations are consistent with the theory of the giant dipole resonance, and apply the obtained new formulae to investigate whether ultraheavy nuclei entrained in protomagnetar outflows can be disintegrated by thermal and nonthermal photons before leaving the stellar envelope. We explore two outflow models: a spherical wind model and a jetted outflow model. For nuclei accelerated to the bulk speed of these outflows, their survival depends on the model and engine properties. For spherical winds, nuclei may survive for the first $\sim 100\mathrm{s}$ post-core collapse, but as the wind Lorentz factor increases, the photodisintegration optical depth sharply rises and nuclei may no longer survive. For the jetted outflows arising from progenitors surrounded with stellar envelopes, nuclei can only survive before the jet breakout time in cases where the central engine has low spin-down energy, that is, with a low magnetic field strength and longer spin period. In progenitors with more extended envelopes, the jet break out time is much longer, allowing for nonthermal photons to readily photodisintegrate nuclei in high spin-down energy cases. These results also have implications for the capabilities of protomagnetars to source ultra-high energy cosmic ray nuclei.

    ↳ astro-ph.HEhep-phnucl-th2 citations
29. 29*

    Efficient Numerical Evaluation of a Two-Loop Contribution to the Dark-Matter Trispectrum

    Andrea Favorito🇨🇭

    We study a two-loop contribution to the dark-matter trispectrum and evaluate it numerically using an infrared-safe integrand. The calculation is organized as an expansion around a fixed reference cosmology: the linear matter power spectrum of the target cosmology is written as a rescaled reference spectrum plus a small difference, and the trispectrum is expanded perturbatively in this difference. For the external momentum configuration considered here, truncating the expansion at third order reproduces the full numerical result with sub-percent accuracy over the range of scales studied, while higher-order terms are strongly suppressed. This reorganization reduces the number of cosmology-independent building blocks that must be computed compared with direct basis decompositions of the linear power spectrum. This provides a practical route to faster evaluations of higher-loop and higher-multiplicity correlators in the Effective Field Theory of Large-Scale Structure.

    ↳ astro-ph.COhep-ph0 citations
30. 30*

    Comment on: "Third-order corrections to the slow-roll expansion: Calculation and constraints with Planck, ACT, SPT, and BICEP/Keck [2025 PDU 47 101813]"

    Pierre Auclair🇫🇷 · Christophe Ringeval🇧🇪

    We point out that several terms in the third-order corrections to the slow-roll power spectra presented by Ballardini et al. [1] are incorrect. The authors of that work claim that their result differ from the ones originally presented by Auclair & Ringeval [2] due to some different approximation schemes. However, in our original work, all terms at all orders have been derived exactly and any difference between two expansions performed at the same pivot wavenumber signals a problem. As we show in this comment, Ballardini et al. [1] have misevaluated some definite three-dimensional integrals by integrating a truncated Taylor expansion instead of Taylor expanding an integral. Our claim is backed-up with a Monte-Carlo numerical integration of the incriminated three-dimensional integrals, which, unsurprisingly, matches the analytical value derived in Auclair & Ringeval [2].

    ↳ astro-ph.COgr-qchep-phhep-thPhys.Dark Univ.(2026)·1 citation
31. 31*

    Chiral-Maxwell Cavity EFT: Photon Condensation and Quantum-Optics Limits

    Fabrizio Canfora🇨🇱 · Mauricio Ipinza🇨🇱 · Simon Riquelme🇨🇱

    We develop an analytic, fully field-theoretic description of how a hadronic medium can induce photon condensation in a cavity. Starting from leading-order Chiral Perturbation Theory minimally coupled to Maxwell theory, we construct a consistent truncation to the lowest hadronic and gauge modes that still supports a non-vanishing baryon (topological) density. The resulting reduced dynamics is an effective \(1+1\) theory whose couplings retain memory of the three-dimensional cavity through discrete winding and transverse holonomy data. Integrating out the heavy hadronic mode at one loop yields a gauge-invariant effective potential for the lowest photonic cavity mode, from which we derive analytic criteria for a condensed window. In the opposite hierarchy, integrating out the gauge mode produces a one-loop deformation of a sine--Gordon-type EFT for the chiral mode and makes explicit where scale separation fails and the full coupled system must be kept. Upon quantization, the reduced theory maps onto standard nonlinear quantum-optics Hamiltonians, including a two-photon Rabi limit and quartic single-mode photonic models whose trivial and condensed branches obey distinct selection rules. This provides a concrete bridge between finite-density hadronic physics and experimentally familiar nonlinear-cavity diagnostics.

    ↳ hep-thhep-phnucl-th0 citations
32. 32*

    Thermalization of Neutrinos in a Neutron Star Merger Simulation

    Mark G. Alford🇺🇸 · Liam Brodie🇺🇸 · Francois Foucart🇺🇸 · Alexander Haber🇺🇸

    We study the neutrino distributions that arise in a simulation of a neutron star merger that uses a Monte Carlo (MC) neutrino transport scheme. In a snapshot taken 1 ms after merger, we calculate relevant observables to test when neutrinos behave like a thermalized gas, and when a free-streaming picture is more appropriate. We find that in hot, dense regions where neutrino-matter interactions are frequent, MC neutrino and antineutrino distributions are consistent with thermalized neutrinos. In moderately warm regions, where neither approximation is expected to hold, we find significant departures from the predictions of the thermalized-neutrino approximation, particularly for the (anti)neutrino average opacity and net rate of absorption per baryon, even when average energies appear approximately thermal. At lower temperatures, MC results approach the free-streaming limit. Our results demonstrate that energy-averaged agreement with thermalized-neutrino assumptions does not guarantee accurate weak interaction rates. Non-equilibrium aspects of the neutrino distribution are therefore crucial for neutrino-mediated microphysics such as composition evolution in the early post-merger phase.

    ↳ astro-ph.HEhep-phnucl-thPRD(2026)·4 citations
33. 33*

    Enhanced Neutrino Cooling from Parity-Doubled Nucleons in Neutron Star Cooling Simulations

    Rodrigo Negreiros🇺🇸 · Liam Brodie🇺🇸 · Jan Steinheimer🇩🇪 · Veronica Dexheimer🇺🇸 · Robert D. Pisarski🇺🇸

    Although restoration of chiral symmetry is predicted by quantum chromodynamics to take place at high baryon density, most modeling of neutron star interiors disregards a chiral phase transition. We model neutron star cores with a parity doublet model, which allows for dynamical chiral symmetry restoration and predicts the appearance of the parity partners of nucleons and hyperons at large densities, as well as deconfined quark matter. We study the thermal evolution of neutron stars, focusing for the first time on the impact of Urca processes involving the parity partners in neutron star cooling simulations. We find that Urca processes for the parity partners of the nucleons significantly affect the thermal evolution of massive stars and allow for improved agreement with observed surface temperature and ages.

    ↳ astro-ph.HEhep-phnucl-th6 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.