Wed·Aug 13, 2025Wednesday·August 13, 2025

1. 01*

   Precision calculation of $N_{\text{eff}}$ with Neutrino Direct Simulation Monte Carlo

   Oleksii Ihnatenko🇺🇦 · Maksym Ovchynnikov🇨🇭

   Neutrino Direct Simulation Monte Carlo ($\nu$DSMC) is a Monte Carlo method for solving the neutrino Boltzmann equation in the early Universe, designed to track the evolution of cosmic neutrinos across a wide range of cosmological scenarios. We develop a complete $\nu$DSMC solver that consistently incorporates the effects of the electron mass, three-flavour neutrino oscillations, and finite-temperature QED corrections to the thermodynamics of the electromagnetic plasma. As a first application, we perform a high-precision calculation of neutrino decoupling in the standard cosmological model and obtain $N_{\text{eff}}=3.0439\pm 0.0006$, in excellent agreement with state-of-the-art results.

   hep-phastro-ph.COPRD(2025)·7 citations
2. 02*

   Sweeping the pion chimney for axion-like particles with KOTO

   Reuven Balkin🇺🇸 · Stefania Gori🇺🇸 · Dean J. Robinson🇺🇸 · Christiane Scherb🇺🇸

   We demonstrate that novel limits on prompt axion-like particles (ALPs) in the hard-to-probe mass range near the neutral pion - the so-called pion chimney - may be obtained from recasting $K_L\to 3{\pi }^0\to 6\gamma$ data taken by the J-PARC KOTO experiment, to search for $K_L\to 2{\pi }^{0}a\to 6\gamma$. We also explore the power of KOTO $6\gamma$ data to probe $K_L\to 2{\pi }^{0}a$ for a broader range of ALP masses, incorporating displaced decays.

   hep-phPRD(2026)·2 citations
3. 03*

   Comment on a "Comment on "Standard Model Mass Spectrum and Interactions In The Holomorphic Unified Field Theory""

   J. W. Moffat🇨🇦 · E. J. Thompson🇨🇦

   A comment on ``Comment on ``Standard Model Mass Spectrum and Interactions In The Holomorphic Unified Field Theory""

   hep-ph8 citations
4. 04*

   Nucleon Energy Correlators as a Probe of Light-Quark Dipole Operators at the Electron-Ion Collider

   Yingsheng Huang🇺🇸 · Xuan-Bo Tong🇫🇮 · Hao-Lin Wang🇨🇳

   We propose nucleon energy correlators (NECs) as a novel framework to probe electroweak light-quark dipole operators in deep inelastic scattering with an unpolarized nucleon. These operators encode chirality-flipping interactions, whose effects are usually quadratically suppressed in unpolarized cross sections. We construct a chiral-odd quark NEC that accesses quark transverse spin via azimuthal angle asymmetries in the energy flow of the target fragmentation region. These asymmetries serve as clean and powerful observables, enabling linear constraints on the quark dipole couplings. Unlike existing methods, our approach requires neither polarized nucleon beams nor final-state hadron identification, relying instead on fully inclusive calorimetric measurements. This work establishes one of the first applications of energy correlator observables to new physics searches and opens a promising direction for precision studies of chirality-flipping effects at electron-ion colliders.

   hep-phnucl-thPRL(2026)·14 citations
5. 05*

   Baryon and Pseudoscalar Meson Octets within a Unified broken SU(6) symmetry

   Luiz L. Lopes🇧🇷

   In this work, I discuss neutron stars with hyperons and anti-kaon condensate. To fix their coupling constants with the vector mesons of the Quantum Hadrodynamics, I use a unified scheme imposing that the Yukawa coupling is an invariant under SU(3) and SU(6) groups. Combining with the G-Parity, I show that some expected results of the kaon and anti-kaon interaction with the nucleus are re-obtained. In the same sense, the naive quark-isospin counting rule is restored in the SU(6) limit. Furthermore, the G-Parity combined with the SU(3) gives us a clear picture of the role played by each meson in the kaon condensation. Numerical results show that the presence of anti-kaons severely compromises the stiffening of the EOS by breaking the SU(6) symmetry.

   hep-phPRD(2026)·1 citation
6. 06*

   WIMP Dark Matter within the dark photon portal

   X. G. Wang🇦🇺 · B. M. Loizos🇦🇺 · A. W. Thomas🇦🇺

   We test the dark photon as a portal connecting to the dark sector in the case of Dirac fermion and complex scalar dark matter with masses up to 1 TeV. Both the dark photon and the $Z$ boson contribute to the dark matter annihilation and dark matter--nucleon scattering processes. We derive the lower limits on the dark parameters from thermal relic density. The corresponding spin-independent dark matter--proton cross sections are compared with the upper bounds set by direct detection. We explore the allowed regions of the dark parameter space that are consistent with these constraints.

   hep-phastro-ph.COhep-exJ.Phys.G(2026)·1 citation
7. 07*

   Production of $J/\psi p\bar{p}$ in electron-positron collisions

   Xiao-Yu Zhang🇨🇳 · Yi-Lin Song🇨🇳 · Feng-Kun Guo🇨🇳

   The discoveries of the hidden-charm $P_c$ pentaquarks by the LHCb Collaboration have been not confirmed by other experiments yet. It is desirable to investigate the feasibility of observing them in other experiments. We present an order-of-magnitude estimate of the cross section of the $e^{+}{e}^{-}\to J/\psi p\bar{p}$ process, where the hidden-charm pentaquarks may be searched for, and find it to be of $\mathcal{O}(4\text{fb})$ when the $e^{+}{e}^{-}$ c.m. energy is around 6 GeV. The cross section for $e^{+}{e}^{-}\to P_c\bar{p}$ is then estimated to be $\lesssim \mathcal{O}(0.1\text{pb})$. Thus, it is promising to search for $P_c$ at the future high-luminosity super tau-charm facilities with annual integrated luminosity about $1a{b}^{-1}$. We also predict the branching fraction of ${\rm Y}\to J/\psi p\bar{p}$ to be of $\mathcal{O}(2\times 10^{-6})$, which can be tested at $B$ factories.

   hep-phhep-exPLB(2026)·2 citations
8. 08*

   Detecting Sterile Neutrino Dark Matter at MeV Gamma-Ray Observatories

   Subaru Fujisawa🇯🇵 · Tatsuya Hayashi🇯🇵 · Shigeki Matsumoto🇯🇵 · Yuki Watanabe🇯🇵

   We explore the indirect detection of sterile neutrino dark matter within the gauged $U(1{)}_{B-L}$ extension of the Standard Model, in which three right-handed neutrinos account for neutrino masses, the baryon asymmetry, and dark matter. Focusing on the MeV mass range, we investigate two decay channels: the radiative decay $N\to \nu \gamma$, which produces a monochromatic photon, and the three-body decay $N\to e^{-}{e}^{+}\nu$, which leads to a 511 keV photon signal from positronium decay. Taking the upcoming COSI mission as a case study, we show that both signals are experimentally accessible and complementary, with the 511 keV channel extending the sensitivity reach up to $O(100)$ MeV. We propose a novel analysis strategy in Compton data space to isolate the diffuse 511 keV emission. Furthermore, we incorporate, for the first time, the Sommerfeld enhancement in the decay width of $N\to e^{-}{e}^{+}\nu$, enabling more accurate predictions of the signal near the kinematic threshold. The combined observation of both channels would provide a distinctive and testable signature of the sterile neutrino dark matter hypothesis.

   hep-phJHEP(2026)·3 citations
9. 09*

   The spectral reconstruction problem for thermal photon and dilepton rates

   Anthony Francis🇹🇼

   Thermal photon and dilepton rates are important probes for understanding the quark-gluon plasma and QCD at high temperatures. As a consequence there is a strong interest to determine them using lattice QCD calculations. However, this is made difficult as they are related to thermal spectral functions that are not directly accessible through lattice calculations. Instead they are indirectly obtainable through performing an inverse Laplace-type transformation of Euclidean time lattice correlation functions. In this talk we will present recent results in dynamical QCD with a focus on advancements in determining the photon production rate via spectral reconstruction from lattice data.

   hep-phPoS(2025)·0 citations
10. 10*

    Bjorken initial energy density estimation in Xe-Xe collisions at $\sqrt{s_{NN}}=5.44$ TeV using ALICE

    Mohammad Asif Bhat🇮🇳 · Akankshya Nayak🇮🇳 · P. K. Sahu🇮🇳

    The Bjorken initial energy density (${ϵ}_B$) has been estimated in different centrality classes in Xe-Xe collisions using Bjorken formula. Three different cases have been considered. In Case I, we have fixed the formation time (${\tau }_0$) and varied the area of overlap region ($A_{overlap}$). In Case II, we have fixed both ${\tau }_0$ and $A_{overlap}$ and we have varied both ${\tau }_0$ and $A_{overlap}$ in Case III. We observed that the ${ϵ}_B$ is first increasing and then decreasing while going from central to peripheral collisions in Case I whereas it is decreasing in Case II and III, as expected. The ${ϵ}_B$ value for top central and mid central collisions in Case II and for all centrality classes in Case III are greater than 1 $GeV/(fm{)}^3$, indicating the possibility of QGP medium formation respectively. The ${ϵ}_B$ results of the Pb-Pb at $\sqrt{s_{NN}}=2.76$ and 5.02 TeV are compared. In Case II, it is observed that in the centrality class (0-5)%, the ${ϵ}_B$ value in Xe-Xe collisions at $\sqrt{s_{NN}}=5.44$ TeV is 34.66% less than in Pb-Pb collisions at $\sqrt{s_{NN}}=2.76$ TeV and 57.12% less than at 5.02 TeV. This may be interpreted as, the system size in Xe-Xe collisions at $\sqrt{s_{NN}}=5.44$ TeV is 34.66% smaller than in Pb-Pb collisions at $\sqrt{s_{NN}}=2.76$ TeV and 57.12% smaller than at 5.02 TeV. Similarly in Case III in the centrality class (0-5)%, the ${ϵ}_B$ value in Xe-Xe collisions at $\sqrt{s_{NN}}=5.44$ TeV is 3.22% more than in Pb-Pb collisions at $\sqrt{s_{NN}}=2.76$ TeV and 32.18% less than at 5.02 TeV. This may be interpreted as, the system size in Xe-Xe collisions at $\sqrt{s_{NN}}=5.44$ TeV is 3.22% bigger than in Pb-Pb collisions at $\sqrt{s_{NN}}=2.76$ TeV and 32.18% smaller than at 5.02 TeV. The results obtained in the Case III seems more suitable than Case II.

    hep-phhep-ex0 citations
11. 11*

    Optimal estimation of Higgs-Gauge Boson couplings at the future $e^{+}{e}^{-}$ colliders

    Subhaditya Bhattacharya🇮🇳 · Amir Subba🇮🇳 · Abhik Sarkar🇮🇳

    The proposed $e^{+}{e}^{-}$ collider offers an ideal environment for precise estimation of Higgs boson properties which are of utmost importance to validate the Standard Model of particle physics. We investigate $hVV$ couplings, where $V\in \{Z,\gamma \}$ with single Higgs production associated with $Z$ boson at the proposed $e^{+}{e}^{-}$ machine with $\sqrt{s}=250$ GeV, within the Standard Model Effective Field Theory (SMEFT) framework. We employ the recoil mass of the dilepton system, to select the signal phase space, i.e, $Zh\to l^{+}{l}^{-}b\text{Bar}b$ events. The constraints on the Wilson coefficients (WCs) are obtained using the optimal observable technique (OOT). On comparison with the current experimental limits at $68\%$ CL with $138$ fb${}^{-1}$ luminosity, our limits are tighter by a factor ranging from $1.5-10$ for CP even operators, while CP-odd WCs shows comparable limits.

    hep-phhep-exPRD(2025)·3 citations
12. 12*

    Sensitivity of $W$-boson measurements to low-mass right-handed neutrinos

    Rodrigo Alonso🇬🇧 · Sam Bates🇬🇧 · Chris Hays🇬🇧 · Chris Pollard🇬🇧 · Michael Spannowsky🇬🇧

    A low-mass right-handed neutrino could interact with electroweak bosons via mixing, a mediator particle, or loop corrections. Using an effective field theory, we determine constraints on these interactions from $W$-boson measurements at hadron colliders. Due to the difference in the initial states at the Tevatron and the LHC, $W$-boson decays to a right-handed neutrino would artificially increase the mass measured at the Tevatron while only affecting the difference between $W^{+}$ and $W^{-}$ mass measurements at the LHC. Measurements from CDF and the LHC are used to infer the corresponding parameter values, which are found to be inconsistent between the two. The LHC experiments can improve sensitivity to these interactions by measuring the cosine of the helicity angle using $W$ bosons produced with transverse momentum above $\approx 50$ GeV.

    hep-phPRD(2025)·3 citations
13. 13*

    Superheavy Q-Balls and Cosmology

    J.McDonald🇬🇧

    We propose a model for the cosmological formation of superheavy Q-Balls in the mass range $10^{-7}{M}_{\odot }$ to $10^6{M}_{\odot }$. The model is based on a hidden sector scalar potential motivated by broken scale invariance, for which analytic Q-ball solutions and numerical simulations of condensate fragmentation exist. We show that this potential can produce superheavy Q-balls during the radiation-dominated era. As an example, we show that it is possible to produce Q-balls of mass $\sim 10^6{M}_{\odot }$ and diameter $\sim$ 100 light years, with a number density $\sim 1$ per galaxy. Such early-forming superheavy Q-balls could play a role in galaxy and supermassive black hole (SMBH) formation. We also show that it is possible to form smaller mass Q-balls with large numbers per galaxy volume, that could form SMBH by merging. Finally, we show that it is possible to produce asteroid mass Q-balls that could account for all of the dark matter whilst remaining consistent with observational limits on MACHOs.

    hep-phJCAP(2026)·3 citations
14. 14*

    A comprehensive analysis of Drell-Yan production uncertainties and mass effects at moderate and low dilepton masses

    Ekta Chaubey🇩🇪 · Claude Duhr🇩🇪 · Rhorry Gauld🇩🇪 · Pooja Mukherjee🇩🇪

    We present a thorough investigation of the sources of uncertainties to the Drell-Yan production using state-of-the-art predictions for both neutral and charged current channels, focusing on the low invariant mass region. Differential predictions for the invariant mass spectrum are provided at N${}^3$LO supplemented with exact charm and bottom quark mass effects calculated at $\mathcal{O}({\alpha }_s^2)$. The impact of PDF choices (including approximate N${}^3$LO), scale variations, the variation of the strong coupling constant, and impact heavy quark mass effects on the distributions is studied in detail. We also comment on the correlation of high-energy astrophysical processes with the low-mass DY region.

    hep-phJHEP(2026)·1 citation
15. 15*

    Quarkonium in a QCD medium with momentum-dependent relaxation time

    Sunny Kumar Singh🇮🇳 · Samapan Bhadury🇵🇱 · Ritesh Ghosh🇺🇸 · Manu Kurian🇮🇳

    In this study, we explore the properties of quarkonia in a hot QCD medium using a newly proposed collision kernel that consistently incorporates the particle's momentum dependence into the relaxation time scale of the medium. The longitudinal component of the gluon self-energy, along with the Debye screening mass, is computed within the one-loop hard thermal loop framework by incorporating non-equilibrium corrections. A modified kinetic theory with an extended relaxation time approximation is employed to model the non-equilibrium dynamics of the QCD medium. The sensitivity of the heavy quarkonia potential to the momentum dependence of the relaxation time is studied. Further, we studied the binding energy and thermal width of quarkonia states within this new kinetic theory. Sizable variations in the temperature behavior of these quantities are observed in comparison with the standard relaxation time approximation method due to the particle momentum dependence on the relaxation timescale of the QCD medium. Our findings highlight that accounting for the microscopic nature of the collision timescale is crucial for understanding the quarkonium behavior in a QCD medium.

    hep-phhep-thnucl-thPRD(2025)·1 citation
16. 16*

    Quantum Sensing Radiative Decays of Neutrinos and Dark Matter Particles

    Zhongtian Dong🇺🇸 · Doojin Kim🇺🇸 · Kyoungchul Kong🇺🇸 · Myeonghun Park🇰🇷 · Miguel A. Soto Alcaraz🇺🇸

    We explore a novel strategy for detecting the radiative decay of very weakly interacting particles by leveraging the extreme sensitivity of quantum devices, such as superconducting transmon qubits and trapped ion systems, to faint electromagnetic signals. By modeling the effective electric field induced by the decay photons, we evaluate the response of quantum sensors across two particle physics scenarios: the cosmic neutrino background and two-component dark matter. We assess the discovery potential of these devices and outline the parameter space accessible under current experimental capabilities. Our analysis demonstrates that quantum sensors can probe radiative decays of dark matter candidates using existing technology, while probing neutrino magnetic moments beyond current limits will require scalable quantum architectures with enhanced coherence.

    hep-phhep-ex7 citations
17. 17*

    Dark Higgs-strahlung at Belle II: A distinctive dark sector signature with displaced vertices and missing energy

    Francesca Acanfora🇩🇪 · Felix Kahlhoefer🇩🇪

    Dark photons with kinetic mixing are compelling mediators for the interactions between dark matter and Standard Model particles. While most experimental searches focus on fully visible or fully invisible decays of dark photons, we explore processes that involve dark Higgs-strahlung, i.e. the emission of a dark Higgs boson connected to the mass generation of the dark photon. If the dark Higgs boson is the lightest dark sector particle, it is expected to be long-lived and decay into Standard Model particles via Higgs mixing. At electron-positron colliders, dark Higgs-strahlung may occur either in isolation (leading to a single displaced vertex and missing energy) or accompanied by a photon from initial-state radiation. Both signatures offer distinctive kinematic features, such as peaks in photon energy or missing invariant mass, which enable efficient background suppression and enhances sensitivity beyond existing searches. Our study suggests that Belle II could significantly improve coverage of dark sector models by targeting this previously unexplored final state and that combining dark Higgs-strahlung events with and without additional photon offers great potential for reconstructing the properties of the dark sector.

    hep-phJHEP(2025)·3 citations
18. 18*

    The Neutrino Kaleidoscope: Searches for Non-Standard Neutrino Oscillations at Neutrino Telescopes with a TeV Muon Accelerator Source

    Nicholas W. Kamp🇺🇸 · Gray Putnam🇺🇸

    Muon accelerators, a potential technology for enabling $\mathcal{O}$(10 TeV) parton center of mass energy collisions, would also source an intense, collimated beam of neutrinos at TeV energies. The energy and size of this beam would be excellently matched as a source for existing and planned neutrino telescopes: gigaton-sized detectors of astrophysical neutrinos at and above TeV energies. In this paper, we introduce the technical considerations and scientific reach of pairing a muon accelerator source of neutrinos with a neutrino telescope detector, a combination we dub the ''Neutrino Kaleidoscope''. In particular, such a pairing would enable searches for non-standard oscillations of the beam neutrinos as they traverse the earth between source and detector. These non-standard neutrino oscillations could be sourced by Lorentz invariance violation, which a neutrino kaleidoscope could probe up to the quantum gravity-motivated Planck scale. Such a search would also have a reach on sterile neutrinos orders of magnitude beyond existing terrestrial limits. Finally, we touch on some of the non-oscillation potential of a neutrino kaleidoscope.

    hep-phhep-exPRD(2026)·2 citations
19. 19*

    Recent Highlights from the STAR Experiment

    Rutik Manikandhan🇺🇸

    We summarize the latest correlation and fluctuation measurements derived from the RHIC Beam Energy Scan-II (BES-II) data, collected by the STAR experiment. We will focus on the recent results of higher-order net-proton cumulants ($C_1-C_4$) in the energy range of 7.7 to 27 GeV Au+Au collisions. Furthermore, we will present measurements of transverse momentum correlations of charged particles, particularly focusing on 2-particle correlators and their dependency on centrality in 3.0 and 3.2 GeV Au+Au collisions.

    ↳ nucl-exhep-exhep-phPoS(2026)·0 citations
20. 20*

    General Fourier expansion of post-Newtonian binary dynamics based on a quasi-Keplerian framework

    Xiaolin Liu🇨🇳 · Zhoujian Cao🇨🇳

    We have introduced a new method for computing gravitational-wave emission from nonspinning binaries which systematically unifies the various integrals arising in the Fourier expansions of post-Newtonian dynamics, providing a simple, practical scheme for calculations at arbitrary precision. Using this approach, we derived the full set of 3PN dynamical quantities and gravitational-wave Fourier modes and have released the corresponding numerical code as open source. Furthermore, when radiation-reaction effects is not included, we found that the tail contribution to the energy and angular momentum fluxes can be resummed into an exceptionally compact expression with the help of the new method. These advances pave the way for more convenient and accurate frequency-domain waveform modeling in the future.

    ↳ gr-qcastro-ph.IMhep-phPRD(2025)·2 citations
21. 21*

    Diquarks in lattice QCD

    Anthony Francis🇹🇼

    Diquarks are often invoked as QCD effective degrees of freedom to describe baryons as well as certain exotic hadrons in phenomenology. However, even though they are successful in describing many of these low lying QCD states, they and their properties have been difficult to pin down. Here we present progress in studying diquarks in a gauge-invariant setup through embedding them in a parent hadron containing a heavy spectator quark using lattice QCD calculations.

    ↳ hep-lathep-phPoS(2025)·0 citations
22. 22*

    Constraining Super-Heavy Dark Matter with the KM3-230213A Neutrino Event

    Roberto Aloisio🇮🇹 · Antonio Ambrosone🇮🇹 · Carmelo Evoli🇮🇹

    Recently, the KM3NeT collaboration detected an astrophysical neutrino event, KM3-230213A, with an energy of approximately $220\mathrm{PeV}$, providing unprecedented insights into the ultra-high-energy Universe. In this study, we introduce a novel likelihood framework designed to leverage this event to constrain the properties of super-heavy dark matter (SHDM) decay. Our approach systematically integrates multi-messenger constraints from galactic and extragalactic neutrino flux measurements by IceCube, the absence of comparable neutrino events at IceCube and Auger observatories, and the latest gamma-ray experiment upper limits. Our findings impose the most stringent constraints to date, placing a lower bound on the SHDM lifetime at $\gtrsim 5\cdot 10^{29}-10^{30}\mathrm{s}$. Importantly, we identify, for the first time, the significant potential of galactic neutrino flux measurements in advancing dark matter research. Future investigations targeting astrophysical neutrinos originating from the Galactic Center at energies above $10\mathrm{PeV}$ will be crucial, not only for understanding the origin of the cosmic-ray knee but also for exploring the possible contributions of super-heavy dark matter to our Universe.

    ↳ astro-ph.HEhep-phPRD(2026)·16 citations
23. 23*

    Spacetime Curvature as a Probe of Exotic Core Phases in Neutron Stars within Modified Gravity

    Sayantan Ghosh🇮🇳 · Bharat Kumar🇮🇳 · Subhash Mahapatra🇮🇳

    In this study, we investigate the effect of Energy-Momentum Squared Gravity (EMSG) on the curvature of neutron stars (NSs) by using three relativistic mean-field (RMF) equations of state (EOSs) and three hadron-quark phase transition (HQPT) EOSs. Neutron stars, with their extreme densities and strong gravitational fields, provide an ideal laboratory for testing General Relativity (GR) in the high-curvature regime and for exploring possible deviations via modified gravity. EMSG extends GR by including nonlinear terms involving the energy-momentum tensor, characterized by a coupling parameter $\alpha$. We focus on the Kretschmann, Ricci, and Weyl curvature scalars, analyzing their dependence on baryon density and radial coordinate for varying values of $\alpha$. Our results indicate that EMSG can significantly alter the curvature profiles of neutron stars. In particular, the magnitude of both Weyl and Kretschmann scalars increases (decreases) for a positive (negative) EMSG parameter, with the former exhibiting a larger dependence. Similarly, the surface curvature (SC) is notably affected by $\alpha$. Interestingly, we further observe distinct discontinuities in the curvature profiles at hadron-quark phase transitions, especially in the soft and intermediate HQPT models. These signatures may provide observable imprints of exotic core phases in neutron stars.

    ↳ nucl-thgr-qchep-phhep-thPRD(2026)·6 citations
24. 24*

    Carpet-3 300 TeV Photon Event as an Evidence for Lorentz Violation

    Hanlin Song🇨🇳 · Bo-Qiang Ma🇨🇳

    The detection by the Carpet-3 Group of a 300 TeV photon, observed 4536 seconds after the prompt emission of the historic gamma-ray burst GRB 221009A, provides unprecedented opportunities to test Lorentz invariance violation (LV) at energy scales approaching the Planck regime. By analyzing the temporal and spatial properties of this ultra-high-energy photon in conjunction with lower-energy photons from other bursts and the same burst, we demonstrate consistency with subluminal LV scenarios characterized by an energy scale \( E_{\rm LV} \sim 3 \times 10^{17} \, \rm{GeV} \). This work bridges multi-year LV studies using GeV-TeV photons and establishes GRB 221009A as a pivotal laboratory for quantum spacetime phenomenology.

    ↳ astro-ph.HEgr-qchep-phPLB(2025)·7 citations
25. 25*

    Constraints on the varying electron mass and early dark energy in light of ACT DR6 and DESI DR2 and the implications for inflation

    Yo Toda🇯🇵 · Osamu Seto🇯🇵

    Primarily motivated by the Hubble tension, we analyze the varying electron mass model and axionlike early dark energy model (EDE) using baryon acoustic oscillation data from DESI DR2 data and including the recent results from ACT DR6. Our analysis indicates that $m_e/m_{e0}=1.0081\pm 0.0046$ and the energy fraction of EDE is constrained as $f_{\mathrm{EDE}}<0.016$. Since those cosmological models fit with different spectral index $n_s$, we show the posterior of those models on the ($n_s-r$) plane and point out that, for example, Starobinsky inflation works for varying electron mass model while the standard supersymmetric hybrid inflation is preferred in the EDE model.

    ↳ astro-ph.COgr-qchep-phJCAP(2026)·19 citations
26. 26*

    Strings from Almost Nothing

    Clifford Cheung🇺🇸 · Grant N. Remmen🇺🇸 · Francesco Sciotti🇪🇸 · Michele Tarquini🇺🇸

    We argue that string theory emerges inevitably from a few simple assumptions about physical scattering. Consistency alone requires that all tree-level four-point scattering amplitudes exhibit vanishing residues at prescribed values of the momentum transfer. Assuming ultrasoft high-energy behavior, we then prove that the space of minimally consistent amplitudes, whose residues exhibit these mandated zeros and nothing more, collapses uniquely onto the celebrated Veneziano and Virasoro-Shapiro amplitudes of string theory. Similar logic also applies to five-point scattering.

    ↳ hep-thhep-phPRL(2026)·26 citations
27. 27*

    Quantifying non-invertible chiral symmetry breaking

    Finn Gagliano🇬🇧

    It has recently been suggested that the chiral symmetry of the Standard Model is not explicitly broken by its ABJ anomaly, but is instead made non-invertible. In this work, I quantify the breaking of non-invertible symmetries of this type by calculating the symmetry breaking scales and effective charges $q(r)$ originally studied for continuous invertible higher-form symmetries. As an example I consider the explicit breaking of the chiral symmetry of massless QED by introducing Yukawa couplings between the electron and a massive real scalar in the UV. I briefly comment on how one might quantify the breaking of general non-invertible symmetries.

    ↳ hep-thhep-ph5 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.