Wed·Jul 23, 2025Wednesday·July 23, 2025

1. 01*

   Covariant reggeization framework for diffraction. Part I: Hadronic tensors in Minkovsky space-time of any dimension

   Roman Ryutin🇷🇺

   In this paper we consider the general structure of irreducible tensor representations of the Poincaré group of arbitrary space-time dimension $D$ with multiple sets of Lorentz indices and different ways to construct them from basic elements (Lorentz vectors and the metric tensor). Then we apply the same methods to obtain the expansion of general hadronic tensors in terms of these irreducible tensors. We propose to use an effective approach in hadronic diffraction, which was usually called covariant reggeization, and obtain basic functions and tensors to calculate all the diffractive cross-sections.

   hep-ph0 citations
2. 02*

   Three-loop induced neutrino mass model in a non-invertible symmetry

   Hiroshi Okada🇨🇳 · Yoshihiro Shigekami🇨🇳

   We propose a new type of radiatively induced neutrino masses at three-loop level based on the Ma model, introducing a non-invertible symmetry in the class under a ${\mathbb{Z}}_2$ gauging of ${\mathbb{Z}}_6$ symmetry and adding three isospin doublet vector-like fermions $L^{\prime }$ and singlet boson $S_0$. Under this symmetry, the Yukawa interactions directly related to the neutrino masses are not allowed at tree-level. However it is allowed at one-loop level due to $L^{\prime }$ and $S_0$ as well as $\eta$, which is no longer invariant under this symmetry. Therefore, the symmetry is dynamically broken. Intriguingly, $\eta$ plays important roles in contributing to both the radiative matrices $y^{\eta }$ and $m_{\nu }$. After constructing our model, we show some numerical analyses to satisfy the lepton flavor violations, muon anomalous magnetic dipole moment, and a boson dark matter candidate $S_0$ or ${\eta }_R$ for the cases of normal hierarchy and inverted hierarchy. Then, we demonstrate allowed space for our input parameters.

   hep-ph21 citations
3. 03*

   Probing Double-Peaked Gamma-Ray Spectra from Primordial Black Holes with Next-Generation Gamma-Ray Experiments

   C. J. Ouseph🇰🇷 · Giorgio Busoni🇦🇺 · John Gargalionis🇦🇺 · Sin Kyu Kang🇰🇷 · Anthony G. Williams🇦🇺

   Primordial black holes (PBHs), hypothesized to form in the early universe from gravitational collapse of density fluctuations, represent a well-motivated dark matter (DM) candidate. Their potential detection through gamma-ray signatures arising from Hawking radiation would provide definitive evidence for their existence and constrain their contribution to the DM abundance. Unlike conventional DM candidates, PBHs emit a unique, thermal-like spectrum of particles as they evaporate, including photons, neutrinos, and possible beyond-the-Standard Model particles. Future high-sensitivity gamma-ray observatories, such as e-ASTROGAM and other next-generation telescopes, will play a pivotal role in this search. With improved energy resolution and sensitivity, these missions can disentangle PBH-originating photons from astrophysical backgrounds, probe subtle spectral features such as multi-peak structures, and test exotic evaporation models. Such observations could either confirm PBHs as a viable DM component or place stringent limits on their abundance across critical mass windows. In this work, we explore the distinguishing features of a double-peaked gamma-ray spectrum produced by PBHs, focusing on the asteroid-mass window ($10^{15}$ g to $10^{17}$ g), where Hawking radiation peaks in the MeV to GeV range. Using a likelihood-based analysis, we demonstrate how future missions could discriminate between single- and double-peaked PBH scenarios, the latter arising in cosmological models predicting multi-modal PBH mass distributions. Our results highlight the diagnostic power of spectral shape analysis in identifying PBH populations and constrain the parameter space for which a double-peaked signal could be detectable above background.

   hep-phastro-ph.COastro-ph.GAastro-ph.HE3 citations
4. 04*

   Split supersymmetry and hybrid inflation in light of Atacama Cosmology Telescope DR6 data

   Nobuchika Okada🇺🇸 · Qaisar Shafi🇺🇸

   Inspired by the recent measurement of the scalar spectral index, $n_s=0.9743\pm 0.0034$, by the Atacama Cosmology Telescope (ACT) DR6 data, we present an update on the split supersymmetry hybrid inflation model, also known as $\mu$-term hybrid inflation. The model employs a canonical Kähler potential but incorporates an additional renormalizable term in the superpotential $W$, which yields the MSSM $\mu$-term following supersymmetry breaking. This additional term in $W$ is responsible for a high reheat temperature, $T_r\gtrsim 10^{12}$ GeV, and consequently the necessity of split supersymmetry in this class of models. The predicted scalar spectral index is in excellent agreement with the ACT measurement and $r$, the tensor to scalar ratio, is estimated to be less than or of order $10^{-2}-10^{-3}$. For the running of the scalar spectral index we find $|d{n}_s/d\ln k|=O(10^{-4})$. With $T_r\gtrsim 10^{12}$ GeV, leptogenesis is readily implemented in this class of models. A wino-like LSP with mass of around 2 TeV is a plausible dark matter candidate.

   hep-phastro-ph.COPLB(2026)·7 citations
5. 05*

   Correlation function for the $n{\bar{D}}_{s0}^{\ast }(2317)$ interaction and the issue of elastic unitarity

   Natsumi Ikeno🇯🇵 · Eulogio Oset🇪🇸

   We study the interaction of a neutron with the ${\bar{D}}_{s0}^{\ast }(2317)$ resonance and look at the amplitude below threshold and close above threshold. The study is done from the perspective that the $D_{s0}^{\ast }(2317)$ resonance is a molecular state of $DK$ in $I=0$. To study this interaction, we use the Fixed Center Approximation to Faddeev equations that considers the $DK$ molecule as the cluster and the neutron as the external particle. We improve the Fixed Center approach to implement elastic unitarity around threshold, which is needed to obtain scattering parameters and to evaluate the $n{\bar{D}}_{s0}^{\ast }(2317)$ correlation function that we determine here. One interesting result of the study is the appearance of a resonant state below threshold with a binding of about 130 MeV and a width of about 80 MeV, which we suggest to look at in reactions measuring the invariant mass of $\pi \Sigma \bar{D}$. The ALICE collaboration has initiated studies of this type, by looking at the $p{f}_1(1285)$ correlation function, and we can only encourage work in this direction which should provide much valuable information on the nature of many resonant states.

   hep-phnucl-exnucl-thPRD(2025)·12 citations
6. 06*

   A unified thermodynamic framework for coextensive dark matter admixed strange stars

   Samstuti Chanda🇮🇳 · Ranjan Sharma🇮🇳

   We investigate the structural and physical properties of a strange star admixed with self-interacting bosonic dark matter. The total energy density is modelled as a weighted combination of quark matter and dark matter components regulated by a fixed local volume fraction. The quark component is described by a linear equation of state, while the dark matter follows a mean-field EOS with repulsive self-interactions. By combining these EOSs into a barotropic effective EOS derived from a unified thermodynamic potential, the two-fluid system is reformulated as a thermodynamically closed and mechanically equilibrated configuration. The construction preserves the dynamical distinction between the quark and dark sectors but treats them as a macroscopically unified mixture governed by a single hydrostatic equilibrium equation. This framework identifies the entirely coextensive limit of two-fluid models as a physically meaningful and thermodynamically closed configuration, providing a coherent macroscopic closure that links dark matter-strange matter microphysics to stellar observables. Using the effective EOS, we solve the governing Tolman-Oppenheimer-Volkoff (TOV) equations to obtain the mass-radius relationship by varying the model parameters. Our results reveal distinct modifications to the $M-R$ profiles, suggesting observable signatures that could offer insights into the impacts of dark matter in extreme astrophysical environments. We note that even a modest dark matter admixture softens the effective equation of state and shrinks the maximum mass limit. We discuss the relevance of our investigation in the context of recent observational data available for pulsars, such as XTE J1814-338, PSR J0348+0432, PSR J0740+6620 and PSRJ0952-0607.

   hep-phgr-qcEPJC(2026)·3 citations
7. 07*

   Longitudinal Structure Function at the Limit $x=Q^2/s$

   G.R.Boroun🇮🇷

   The longitudinal structure function for nucleons and nuclei is considered at fixed $\sqrt{s}$ and $Q^2$ to the minimum value of $x$ given by $Q^2/s$. This is done using the expansion method and color dipole model in the next-to-leading order approximation. The extracted longitudinal structure functions were consistent with HERA hepdata [ https://www.hepdata.net/record/ins1377206] and the determination of $F_L$ at $x=Q^2/s$ [Frank E.Taylor, Phys. Rev. D {\bf111}, 052001 (2025)] at moderate and large $Q^2$ values. The results, consistent with the dipole picture at low $Q^2$ values, show that the longitudinal structure function is small as expected due to the transverse polarization of the exchanged photon and the strong suppression of the dominant gluon component. Nonlinear corrections to the nuclear longitudinal structure function at low values of $x$ and $Q^2$ are also considered. These results may enhance the deep inelastic scattering neutral current data in future colliders at low $x$ and low $Q^2$. The longitudinal structure functions for deuterium at low four-momentum transfer squared, $Q^2<1{\mathrm{GeV}}^2$ at the LO and NLO approximations are determined and compared with the JLab E00-002 data.

   hep-phPRD(2025)·5 citations
8. 08*

   Probing Large $N_f$ Through Schemes

   Alan Pinoy🇧🇪 · Shahram Vatani🇧🇪

   We investigate the reliability of the large $N_f$ expansion of four-dimensional gauge-fermion quantum field theories, focusing on the structure and scheme dependence of the beta function. While the existence of a nontrivial UV fixed point at leading order in $1/N_f$ suggests the possibility of asymptotic safety, the absence of higher-order terms precludes robust conclusions. We analyze the impact of renormalization scheme transformations and show that higher-order corrections inevitably introduce increasingly singular contributions. We prove that at most one renormalization scheme can preserve the dominance of the leading contribution, rendering the truncation trustworthy; in all other schemes, higher-order terms dominate and the expansion becomes unreliable. This result places strong constraints on the physical interpretation of UV fixed points in large $N_f$ theories and emphasizes the need for resummation or non-perturbative control to establish asymptotic safety.

   hep-phhep-th0 citations
9. 09*

   Embeddings of the Standard Model in $E_8$

   Robert A. Wilson🇬🇧

   I present a modified version of the Manogue-Dray-Wilson `octions' model of elementary particles, that overcomes some of the objections to that model that have been raised. In particular, I restore the compactness of the Standard Model gauge group, and show how the symmetry-breaking of the weak $SU(2)$ relates to the symmetry-breaking between the three generations of elementary fermions. In the process of attempting to implement a Dirac equation for three generations of fermions simultaneously, it turns out that some parts of the $E_8$ model are not required for the Standard Model, which is entirely contained in the subalgebra $\mathfrak{so}(7,3)$. In particular a re-interpretation of the Dirac spinors allows us to interpret part of the model as quantum gravity, which is then compared to General Relativity. The general structure of the model shows that the mixing angles depend on masses, and that the masses emerge from quantum interactions with the dynamic background spacetime (vacuum). Some sample calculations are given to support these predictions.

   hep-phmath.GR0 citations
10. 10*

    Fully heavy pentaquark states from QCD sum rules

    Zheng-Lei Jing🇨🇳 · Jian-Rong Zhang🇨🇳

    In this work, we systematically investigate the mass spectra of fully heavy pentaquark states $QQQQ\bar{Q}$ within the framework of QCD sum rules. Employing three configurations of interpolating currents, we obtain the following mass predictions: for the $cccc\bar{c}$ states, the masses are determined to be $7.79_{-0.17}^{+0.18}$ GeV, $7.76_{-0.18}^{+0.23}$ Gev, $7.81_{-0.18}^{+0.17}$ GeV; while for the $bbbb\bar{b}$ states, the corresponding masses are calculated as $22.35_{-0.19}^{+0.19}$ GeV, $22.27_{-0.22}^{+0.22}$ GeV, $22.37_{-0.20}^{+0.18}$ GeV, respectively.

    hep-phhep-exPRD(2025)·3 citations
11. 11*

    Impact of cavities on the detection of quadratically coupled ultra-light dark matter

    Clare Burrage🇬🇧 · Angus Macdonald🇬🇧 · Michael P. Ross🇺🇸 · Gray Rybka🇺🇸 · Elisa Todarello🇬🇧

    Ultra-light scalar fields may explain the nature of the dark matter in our universe. If such scalars couple quadratically to particles of the Standard Model the scalar acquires an effective mass which depends on the local matter energy density. The changing mass causes the field to deviate from its cosmological value in experimental environments. In this work we show that the presence of a local over-density enclosing the experiment, for example a cavity, vacuum chamber, or satellite can strongly suppress the value of the scalar and its gradient in the interior. This makes detection of such scalar dark matter challenging, and significantly relaxes constraints on strongly coupled models. We also discuss the possibility that quadratically coupled ultra-light scalar dark matter could be detected by the differential measurement of the force on two cavities of the same mass but different internal structure.

    hep-phastro-ph.COPRD(2026)·12 citations
12. 12*

    Dark matter explanations for the neutrino emission from the Seyfert galaxy NGC 1068

    Kensuke Akita🇯🇵 · Alejandro Ibarra🇩🇪 · Robert Zimmermann🇩🇪

    We investigate the possibility that the high-energy neutrino flux observed from the Seyfert galaxy NGC 1068 originates from dark matter annihilations within the density spike surrounding the supermassive black hole at its center. The comparatively lower gamma-ray flux is attributed to a dark sector that couples predominantly to Standard Model neutrinos. To explain the absence of a corresponding neutrino signal from the center of the Milky Way, we propose two scenarios: (i) the disruption of the dark matter spike at the Milky Way center due to stellar heating, or (ii) the annihilation into a dark scalar that decays exclusively into neutrinos, with a decay length longer than the size of the Milky Way but shorter than the distance from Earth to NGC 1068.

    hep-phastro-ph.HE5 citations
13. 13*

    Echoes in multi-ALP scenarios

    Shihabul Haque🇮🇳 · Sourov Roy🇮🇳

    We present a theoretical study of axion echoes in the context of multiple ALP models. We begin by reviewing the single ALP case, deriving the conditions for resonance and echo formation. Starting from a set of $N$ ALPs coupled to the photon, we then derive the relevant echo equations for both coherent and incoherent configurations. In the former case, we show that the echo power scales with $N$ leading to sharper amplification and potentially improving sensitivity estimates discussed earlier in literature. Small mass splittings between the ALPs further increase this amplification, even for a $N=2$ case. In the incoherent scenario, we show that the random phases lead to a suppression of the echo power, eventually resulting in observable signals akin to or even weaker than the single ALP case. We also outline the potential experimental implications of our results and discuss prospects for detecting these echoes in a wide range of ALP masses.

    hep-phastro-ph.HEJCAP(2026)·1 citation
14. 14*

    Unravelling the Scalar Sector of Grand Unification: Phenomenology & Implications

    Saurabh K. Shukla🇮🇳

    Grand Unified Theories (GUTs) based on groups like $SO(10)$ and $SU(5)$ unify Standard Model (SM) fermions into irreducible representations (irreps), and predict additional scalar fields beyond the SM Higgs. In $SO(10)$ GUTs, the scalar fields can arise from irreps contributing to the Yukawa sector at the renormalisable level, such as $10_{\mathrm{H}}$, $120_{\mathrm{H}}$, and ${\overline{126}}_{\mathrm{H}}$, or from $16_{\mathrm{H}}$ in non-renormalisable interactions. The direct implications of these scalars include the violation of baryon and lepton number, enabling processes such as nucleon decays, neutron-antineutron oscillation, and potentially accounting for the observed baryon asymmetry of the universe. We systematically analyse their couplings to SM fermions, identifying diquark and leptoquark interactions vertices involving all scalars residing in $10_{\mathrm{H}}$, $120_{\mathrm{H}}$, ${\overline{126}}_{\mathrm{H}}$, and $16_{\mathrm{H}}$ and comprehensively assess their contributions to nucleon decay, neutron-antineutron oscillation, quark flavour violation, and baryogenesis. Constraints on the masses of these scalars, derived from experimental bounds on the aforementioned processes, are also estimated. Conventional GUTs rely on multiple scalar irreps to avoid unrealistic fermion mass relations; for example, minimal $SU(5)$ with $5_{\mathrm{H}}$ predicts degenerate down-quark and charged-lepton masses. We demonstrate that quantum corrections from heavy scalars in a minimally extended $SU(5)$ model can lift this degeneracy, thereby reducing the arbitrariness in the scalar sector, which has been called as indirect impact. This thesis provides a comprehensive examination of the scalar sector's role in GUTs, establishing connections between UV-complete models and observable phenomena.

    hep-phhep-th0 citations
15. 15*

    Scalar-induced Neutrinoless Double Beta Decay in $SU(5)$

    P.S. Bhupal Dev🇺🇸 · Srubabati Goswami🇮🇳 · Debashis Pachhar🇮🇳 · Saurabh K. Shukla🇮🇳

    We discuss the role of heavy scalar fields in mediating neutrinoless double beta decay $(0\nu \beta \beta )$ within the $SU(5)$ Grand Unified Theory framework, extended suitably to include neutrino mass. In such a minimal realistic $SU(5)$ setup for fermion masses, the scalar contributions to $0\nu \beta \beta$ are extremely suppressed as a consequence of the proton decay bound. We circumvent this problem by imposing a discrete ${\mathcal{Z}}_3$ symmetry. However, the scalar contributions to $0\nu \beta \beta$ remain suppressed in this $SU(5)\times {\mathcal{Z}}_3$ model due to the neutrino mass constraint. We find that the $0\nu \beta \beta$ contribution can be enhanced by extending the scalar sector with an additional $15$-dimensional scalar representation with suitable ${\mathcal{Z}}_3$ charge. Such an extension not only yields realistic fermion mass spectra but also leads to experimentally testable predictions in upcoming ton-scale $0\nu \beta \beta$ searches, which can be used as a sensitive probe of the new scalars across a broad range, from LHC-accessible scales up to $\sim 10^{10}\text{GeV}$.

    hep-phJHEP(2026)·1 citation
16. 16*

    Constrain the ${\chi }_{cJ}\to D^{(\ast )}{\bar{D}}^{(\ast )}$ effective couplings via the $X(3872)\to {\pi }^0{\chi }_{cJ}$ decays

    Zhao-Sai Jia🇨🇳 · Gang Li🇨🇳 · Zhen-Hua Zhang🇨🇳

    The hidden-charm decays serve as irreplaceable platforms for probing the structures of charmonium-like states, such as $X(3872)$, $Y(4260)$, $Z_c(3900)$, and their heavy-quark-symmetry partners. In the hadronic molecular scenario, these hidden-charm decays are denominated by intermediate meson loops (IMLs), and the couplings of ${\chi }_{cJ}\to D^{(\ast )}{\bar{D}}^{(\ast )}$ are building blocks of the amplitudes for the pionic and radiative transitions of the charmonium-like states to the ${\chi }_{cJ}$ and $h_c$ states, e.g., $X(3872)\to {\pi }^0{\chi }_{cJ},\pi \pi {\chi }_{cJ},\gamma {\chi }_{cJ}$ and $Y(4260)\to {\pi }^0{h}_c,\eta h_c$. These couplings can not be extracted from the partial decay widths of the ${\chi }_{cJ}$ directly and only have estimated values from the vector meson dominance (VMD) model. Utilizing the recent precise determination of the pole position and the isospin breaking properties of the $X(3872)$, we give an estimation on the upper bounds of the absolute values of the ${\chi }_{cJ}\to D^{(\ast )}{\bar{D}}^{(\ast )}$ couplings. Our results show that the VMD model may over estimate the ${\chi }_{cJ}\to D^{(\ast )}{\bar{D}}^{(\ast )}$ couplings considering the $X(3872)$ as a $D{\bar{D}}^{\ast }$ hadronic molecule with a binding energy about tens of keV. These upper limits can be used and tested in other hidden-charm transitions of the charmonium-like states to the ${\chi }_{cJ}$ and $h_c$.

    hep-phPRD(2025)·3 citations
17. 17*

    Ring-based ML calibration with in situ pileup correction for real-time jet triggers

    Benjamin T. Carlson🇺🇸 · Stephen T. Roche🇺🇸 · Michael Hemmett🇺🇸 · Tae Min Hong🇺🇸

    We present a machine learning (ML) method to calibrate hadronic jet energy in real-time trigger systems of the High-Luminosity Large Hadron Collider (HL-LHC) using an efficient implementation on field programmable gate arrays (FPGA). Regression is done to estimate the transverse energy of jet candidates, using concentric rings of electromagnetic and hadronic contributions in 0.1 x 0.1 towers around fixed-radius cone jet seeds, that accounts for in situ pileup correction. Classification separates hard-scatter jets from those due to pileup using the same inputs; its output provides a correction for the regression estimate. The algorithm is tested on simulated samples using an ATLAS-inspired detector in the dense environment of 200 simultaneous proton-proton collisions per bunch crossing. Our method improves the signal efficiency of saving Higgs pair production in HH -> bbbb by a factor of two over the traditional cone jet algorithm in real-time trigger systems.

    hep-phhep-ex2 citations
18. 18*

    Abelian-Higgs vortices in the oscillating axion background

    Naoya Kitajima🇯🇵 · Shota Nakagawa🇨🇳

    We study the dynamics of Abelian-Higgs vortices in the background of a coherently oscillating axion field. We show that the electric field is induced in the magnetic core of the vortex due to the axion-photon conversion. Moreover, because the electromagnetic field is confined in the vortex and excluded from the superconducting bulk regions due to the Meissner effect, the vortex tube can be regarded as a cylindrical cavity, and our numerical analysis shows that the resonant cavity mode (TM010 mode) can be efficiently enhanced in this tube. We also focus on the interaction of two vortices in the oscillating axion background, resulting in attractive or repulsive forces, even in the case with the BPS limit. These new features open up a new possibility for the axion dark matter search using superconducting devices.

    hep-phcond-mat.supr-conhep-thPLB(2025)·3 citations
19. 19*

    Di-$J/\psi$ structures from the quark Pauli-blocking effect

    Sachiko Takeuchi🇯🇵 · Atsushi Hosaka🇯🇵 · Makoto Takizawa🇯🇵 · Yasuhiro Yamaguchi🇯🇵

    The double-charmonium scattering states such as $J/\psi J/\psi$, ${\eta }_{c}J/\psi$, and ${\eta }_c{\eta }_c$ are investigated by a simplified quark cluster model. It is found that the quark Pauli-principle over the $c\bar{c}c\bar{c}$ system causes a rapid increase and a node in the two-meson phase shifts. The increase is not large enough to be regarded as a resonance, but if it is seen experimentally, that is most likely the quark Pauli-blocking effect.

    hep-phnucl-thPoS(2025)·2 citations
20. 20*

    Electroweak Precision Constraints on Dark Photon Models with Generalized Mixing

    Enrico Bertuzzo🇮🇹 · Csaba Csaki🇺🇸 · Fernanda Huller🇺🇸

    We present a global fit to electroweak precision observables (EWPOs) in dark photon (DP) models containing both kinetic and mass mixing between the DP and the neutral gauge bosons of the Standard Model (SM). Such more general mixing can be the result of an extended scalar sector, which we specify in this paper. We calculate the tree-level contributions to EWPOs due to the mixing with the DP, as well as the leading loop corrections to the oblique parameters due to the extended Higgs sector. In the scalar sector, we find that ample regions of parameter space are still unconstrained by data. In the gauge sector, the excluded region depends strongly on the vacuum expectation values of the scalar fields: for moderate ratios, DP masses in the $(40\text{GeV},1\text{TeV})$ range are excluded; for larger ratios, the limits become indistinguishable from those for standard DPs.

    hep-phJHEP(2026)·3 citations
21. 21*

    Thermal modifications of mesons and energy-energy correlators from real-time simulations of a $U(1)$ lattice gauge theory

    João Barata🇨🇭 · David Frenklakh🇺🇸 · Swagato Mukherjee🇺🇸

    We investigate thermal properties of a $U(1)$ lattice gauge theory in $1+1$-dimensions through real-time simulations. We extract the spectral functions directly coupling to the pseudoscalar and scalar mesons, demonstrating the thermal modifications of these states with increasing temperatures. Introducing the notion of energy-flow operators, we quantify the temporal build-up of correlations in the energy flows across the lattice. We demonstrate that energy-energy correlators fail to factorize to products of energy flows, both in the vacuum and at nonzero-temperature, indicating the presence of non-trivial correlations in the quantum states. Our results constitute a first real-time \textit{ab-initio} study of bound state thermal broadening and finite temperature energy-flow correlations in a gauge theory, providing a benchmark for future studies of hadronic matter under extreme conditions.

    hep-phhep-latquant-phPRD(2025)·10 citations
22. 22*

    Vacuum muon decay and interaction with laser pulses

    B. King🇬🇧 · D. Liu🇬🇧

    Muons decay in vacuum mainly via the leptonic channel to an electron, a muon neutrino and an electron antineutrino. Previous investigations have concluded that muon decay can only be significantly altered in a strong electromagnetic field when the muonic strong-field parameter is of order unity, which is far beyond the reach of lab-based experiments at current and planned facilities. In this letter, an alternative mechanism is presented in which a laser pulse affects the vacuum decay rate of a muon outside the pulse. Quantum interference between the muon decaying with or without interacting with the pulse generates fringes in the electron momentum spectra and can increase the muon lifetime by up to a factor 2. The required parameters to observe this effect are available in experiments today.

    hep-phPRL(2025)·2 citations
23. 23*

    Fast and Fewrious: Stochastic binary perturbations from fast compact objects

    Badal Bhalla🇺🇸 · Benjamin V. Lehmann🇺🇸 · Kuver Sinha🇺🇸 · Tao Xu🇺🇸

    Massive compact objects soften binaries. This process has been used for decades to constrain the population of such objects, particularly as a component of dark matter (DM). The effects of light compact objects, such as those in the unconstrained asteroid-mass range, have generally been neglected. In principle, low-energy perturbers can harden binaries instead of softening them, but the standard lore is that this effect vanishes when the perturber velocities are large compared to the binary's orbital velocity, as is typical for DM constituents. Here, we revisit the computation of the hardening rate induced by light perturbers. We show that although the perturbations average to zero over many encounters, many scenarios of interest for DM constraints are in the regime where the variance cannot be neglected. We show that a few fast-moving perturbers can leave stochastic perturbations in systems that are measured with great precision, and we use this framework to revisit the constraint potential of systems such as binary pulsars and the Solar System. This opens a new class of dynamical probes with potential applications to asteroid-mass DM candidates.

    hep-phastro-ph.COastro-ph.EPastro-ph.SRPRD(2026)·1 citation
24. 24*

    Phenomenology of Fractionally Charged Particles: Two Reps Are Better Than One

    Seth Koren🇺🇸 · Adam Martin🇺🇸

    We continue our study of fractionally charged particles (FCPs) -- particles carrying electric charge a multiple of $e/6$. Discovering an FCP would inform us about both Standard Model physics (what the true gauge group and the one-form global symmetry are) and Beyond the Standard Model physics (ruling out many unified theories), which makes them a high-stakes target for collider searches. Here we find that with two FCPs there are vastly richer phenomenologies compared to the single-particle extensions we previously studied. Stringent constraints on colored FCPs can be dramatically weakened when decays are open; conversely the cross sections of the least visible species can be enlarged by up to $\sim 10^3$, increasing their discovery potential enormously at the LHC and milliQan. Overall, these simple models motivate performing searches for FCPs produced along with jets or leptons, and highlight 'free' discovery potential in reanalyzing existing missing-energy datasets for low-quality tracks.

    hep-phhep-exNPB(2025)·9 citations
25. 25*

    Hot news on the phase structure of the SMEFT

    Mikael Chala🇪🇸 · Maria Cristina Fiore🇪🇸 · Luis Gil🇪🇸

    We perform dimensional reduction of the electroweak sector of the dimension-six SMEFT to order $g^4$ in coupling constants $g$. This analysis includes one-loop contributions to kinetic terms and quartic couplings; as well as two-loop contributions, where operators such as four-fermion interactions first appear, to squared mass terms. Using lattice data, we also provide evidence that, in contrast with previous statements in the literature, the SMEFT may undergo a first-order phase transition even for null $|\varphi {|}^6$ at zero temperature, where $\varphi$ is the Higgs doublet. This opens the door to entirely unexplored directions in model building.

    hep-phPRD(2026)·15 citations
26. 26*

    A linear PDF model for Bayesian inference

    Mark N. Costantini🇬🇧 · Luca Mantani🇪🇸 · James M. Moore🇬🇧 · Maria Ubiali🇬🇧

    A robust uncertainty estimate in global analyses of Parton Distribution Functions (PDFs) is essential at the Large Hadron Collider (LHC), especially in view of the high-precision data anticipated by experimentalists in the High-Luminosity phase of the LHC. A Bayesian framework to determine PDFs provides a rigorous treatment of uncertainties and full control on the prior, though its practical implementation can be computationally demanding. To address these challenges, we introduce a novel approach to PDF determination tailored for Bayesian inference, based on the use of linear models. Unlike traditional parametrisations, our method represents PDFs as vectors in a functional space spanned by specially chosen bases, derived from the dimensional reduction of a neural network functional space, providing a compact yet versatile representation of PDFs. The low-dimensionality of the preferred models allows for particularly fast inference. The size of the bases can be systematically adjusted, allowing for transparent control over underfitting and overfitting, and facilitating principled model selection through Bayesian workflows. In this work, the methodology is applied to a fit of Deep Inelastic Scattering synthetic data, and thoroughly tested via multi-closure tests, thus paving the way to its application to global PDF fits.

    hep-phhep-exJHEP(2026)·12 citations
27. 27*

    Construction of general $N$-body lattice operators with arbitrary momenta

    Haobo Yan🇨🇳 · Chuan Liu🇨🇳 · Liuming Liu🇨🇳 · Yu Meng🇨🇳

    We present a systematic method for constructing lattice QCD operators for systems of an arbitrary number of particles with arbitrary momentum, spin, and internal quantum numbers. Explicit constructions are provided for one-, two-, three-, and four-hadron operators, covering all irreducible representations of the relevant lattice symmetry groups in both rest and moving frames. The construction procedure has been implemented in the open-source package \texttt{OpTion} (Operator construcTion), available at https://github.com/wittscien/OpTion. The paper and the package are designed to serve as a practical and extensible dictionary for future lattice QCD studies, as lattice calculations advance towards increasingly complex hadronic systems.

    ↳ hep-lathep-phJHEP(2025)·7 citations
28. 28*

    Symmetric-asymmetric collision comparison: disentangling nuclear structure and subnucleonic structure effects for small system flow

    Shengli Huang🇺🇸 · Jiangyong Jia🇺🇸 · Chunjian Zhang🇨🇳

    Previous flow measurements in small collision systems were mostly based on highly asymmetric collisions ($p$+Pb, $p$+Au, $d$+Au, ${}^3$He+Au), where both nuclear structure and subnucleonic fluctuations are important. Comparing these asymmetric systems with the newly available symmetric ${}^{16}$O+${}^{16}$O collisions at RHIC and LHC provides a unique opportunity to disentangle these two contributions. Using Glauber models incorporating both nucleon and quark-level substructure, we analyze multiplicity distributions and initial-state estimators: eccentricities ${\epsilon }_n$ for anisotropic flow $v_n$ and inverse transverse size $d_{\perp }$ for radial flow. We find that subnucleonic fluctuations impact O+O collisions differently from asymmetric systems, creating specific patterns in flow observables that enable disentangling the competing contributions. Such experimental comparisons will reduce uncertainties in the initial conditions and improve our understanding of the properties of the QGP-like medium produced in small systems.

    ↳ nucl-thhep-phnucl-exPLB(2025)·6 citations
29. 29*

    Strangeness production in $O+O$ collisions at $\sqrt{s_{\mathrm{NN}}}=7$ TeV using various model approaches

    J. Singh🇨🇱 · M. U. Ashraf🇺🇸 · A. M. Khan🇺🇸 · S. Kabana🇨🇱

    We present the predictions of various observables for strange (${\mathrm{K}}_{\mathrm{S}}^0$, $\Lambda$($\overline{\Lambda }$)) and multi-strange hadrons (${\Xi }^{-}$(${\overline{\Xi }}^{+}$), $\varphi$, and ${\Omega }^{-}$(${\overline{\Omega }}^{+}$)) using the recently updated 3+1D hydrodynamics-based EPOS4 framework and AMPT model. In this study, we report the transverse momentum ($p_{\mathrm{T}}$) spectra, particle yields ($\mathrm{d}N/\mathrm{d}y$), and $p_{\mathrm{T}}$ integrated yield ratios relative to pions for $O+O$ collisions at $\sqrt{s_{\mathrm{NN}}}=7$~TeV. The results reveal that there are indications of stronger radial flow in EPOS4 compared to AMPT. We observe a final state multiplicity overlap with small ($p+p$ and $p+Pb$) and large ($Pb+Pb$) collision systems.

    ↳ nucl-thhep-phInternational Journal of Modern Physics E…·2 citations
30. 30*

    Anisotropic flow predictions for identified and strange hadrons in $O+O$ collisions at $\sqrt{s_{\mathrm{NN}}}$ = 7 TeV using model approaches

    Jagbir Singh🇨🇱 · M. U. Ashraf🇺🇸 · A. M. Khan🇺🇸 · S. Kabana🇨🇱

    In this study, we report the predictions for the flow observables for different centrality classes in $O+O$ collisions. Our predictions utilize two different approaches, hydrodynamic and transport models, to analyze the behavior of the flow coefficients for identified (${\pi }^{\pm }$, $K^{\pm }$ and $p(\overline{p})$) and strange (${\mathrm{K}}_{\mathrm{S}}^0$, $\Lambda$ ($\overline{\Lambda }$), ${\Omega }^{-}$ (${\overline{\Omega }}^{+}$), ${\Xi }^{-}$ (${\overline{\Xi }}^{+}$), $\varphi$) hadrons. We explore particle-by-particle flow and compare the response of the system to initial conditions across various models, which provide insights into the underlying partonic and hadronic dynamics. The study presents comparisons of flow harmonics with the existing experimental measurements and demonstrates how $O+O$ collisions can serve as a benchmark to understand the transition from small to large systems, contributing to our knowledge of the Quark-Gluon Plasma (QGP) and collective phenomena in heavy-ion collisions.

    ↳ nucl-thhep-phSpringer Proc.Phys.(2026)·2 citations
31. 31*

    SUSY Highlights: Current Results and Future Prospects

    Jory Sonneveld (on behalf of the ATLAS and CMS Collaborations)🇩🇪

    At the Large Hadron Collider (LHC) at CERN in Geneva, Switzerland, one of the goals of colliding protons together is to search for new physics. Supersymmetry (SUSY), a popular theory of physics beyond the well-established standard model of particle physics, is a large part of the search program of the ATLAS and CMS multi-purpose detectors located on opposite sides of the 27-kilometer LHC ring. So far no sign of supersymmetry has been found in the most obvious search channels such as all-hadronic searches with jets and missing energy. This led to the development of many new search strategies. A selection of current results, including several observations of deviations from the standard model and novel search techniques, as well as future prospects are discussed in this talk.

    ↳ hep-exhep-ph1 citation
32. 32*

    Flat-band thermodynamics reveals enhanced performance across Otto, Carnot, and Stirling cycles

    Hadi Mohammed Soufy · Colin Benjamin

    Magic-angle twisted bilayer graphene (MATBG) exhibits remarkable electronic properties under external magnetic fields, notably the emergence of flat Landau levels. In this study, we present a comprehensive analysis of MATBG's operational phase diagram under three distinct quantum thermodynamic cycles, i.e., Quantum Otto Cycle (QOC), Quantum Carnot Cycle (QCC), and Quantum Stirling Cycle (QSC). Employing the continuum eight-band model, we evaluate the thermodynamic performance of MATBG across multiple operational modes: heat engine, refrigerator, cold pump, and Joule pump, and benchmark it against other graphene systems such as monolayer graphene, AB-Bernal stacked bilayer graphene, and non-magic-angle twisted bilayer graphene. Our findings reveal that MATBG demonstrates superior heat engine performance in QSC, while achieving high efficiency albeit with reduced work output in QOC. Even though the performance of MATBG as a cold pump or refrigerator is modest in QOC and QSC, it shows notable improvement as a refrigerator in QCC. Additionally, we identify a highly reversible Joule pump mode in both QSC and QOC under strict adiabaticity, underscoring the unique thermodynamic behavior of MATBG.

    ↳ cond-mat.mes-hallhep-phmath-phmath.MP+2PRA(2025)·5 citations
33. 33*

    Cosmological preference for a positive neutrino mass at 2.7$\sigma$: A joint analysis of DESI DR2, DESY5, and DESY1 data

    Guo-Hong Du🇺🇸 · Tian-Nuo Li🇺🇸 · Peng-Ju Wu🇨🇳 · Jing-Fei Zhang🇺🇸 · Xin Zhang🇺🇸

    Neutrinos and dark energy (DE) have entered a new era of investigation, as the latest DESI baryon acoustic oscillation measurements tighten the constraints on the neutrino mass and suggest that DE may be dynamical rather than a cosmological constant. In this work, we obtain a high-confidence measurement of the neutrino mass within a dynamical DE framework. A joint analysis of DESI DR2, cosmic microwave background, DESY5 supernova, and DESY1 weak lensing data yields a total neutrino mass of $\sum m_{\nu }=0.098_{-0.037}^{+0.016}\mathrm{eV}$, indicating a measurement for a non-zero, positive neutrino mass at the $2.7\sigma$ level within the $w_0{w}_a$CDM framework. This high-confidence measurement is driven mainly by these factors: (i) the DESI's preference for a dynamical DE with its equation of state evolving from $w<-1$ at early times to $w>-1$ at late times, thus leading to a larger neutrino mass; (ii) treating $N_{\mathrm{eff}}$ as a free parameter together with the inclusion of weak lensing data, which likewise allows for an increased neutrino mass. In the future, even higher-confidence measurements of neutrino mass are expected with stronger preferences for dynamical DE in light of more complete DESI data releases.

    ↳ astro-ph.COgr-qchep-phhep-thSCPMA(2026)·47 citations
34. 34*

    Gravitational Wave Scattering on Magnetic Fields

    Valerie Domcke🇨🇭 · Camilo Garcia-Cely🇪🇸 · Sung Mook Lee🇨🇭

    The conversion of gravitational to electromagnetic waves in the presence of background magnetic fields is known as the inverse Gertsenshtein effect, analogous to the Primakoff effect for axions. Rephrasing this conversion as a classical electrodynamics problem in the far-field regime of a magnetized region, we derive the angular distribution of the intensity and polarization of the emitted electromagnetic waves. We discuss the interplay of the internal structure of the magnetic field, the polarization of the gravitational wave and the scattering angle, demonstrating for example that a dipolar field can convert an unpolarized stochastic gravitational wave background into polarized electromagnetic emission, with peak emission intensity along the equator. We moreover outline how to incorporate medium effects in this framework, necessary for a realistic 3D description of gravitational wave to photon conversion in the magnetosphere of neutron stars.

    ↳ gr-qcastro-ph.COastro-ph.HEhep-ph+1JCAP(2025)·6 citations
35. 35*

    Weinberg's theorem, phantom crossing and screening

    Philippe Brax🇫🇷

    We consider models where the dilaton, seen as the pseudo-Goldstone boson of broken scale invariance, plays the role of dark energy. We revisit Weinberg's theorem and show that quantum corrections induced by the graviton lead to the screening of the dilaton locally. We also discuss the time evolution of the equation of state and find that phantom crossing is a natural feature of these models. The time variation of the equation of state and its deviation from $-1$ is limited by screening locally and can only be relaxed when the dilaton is allowed to have a mass of the order of the Hubble rate cosmologically, thus going beyond single-field screened dark-energy models. This obstruction extends to all single-field screened models of the chameleon-type where the large mass of the scalar on cosmological scales leads to a negligible variation of the equation of state at low redshift.

    ↳ astro-ph.COgr-qchep-phhep-thPRD(2025)·17 citations
36. 36*

    Angular correlations in neutron-gamma reactions

    Vladimir Gudkov🇺🇸 · Hirohiko M. Shimizu🇯🇵

    Angular correlations for low-energy neutron induced $\gamma$ reactions are calculated using nuclear reaction formalism for multi level neutron capture with arbitrary multiplicities of $\gamma$ transitions. We confirm previous calculations [V. V. Flambaum and O. P. Sushkov, Nucl. Phys.A 435 , 352 (1985)] for dipole transitions obtained with different formalism. The possible applications of n-$\gamma$ correlations for studies of symmetry violations and electromagnetic transitions are discussed.

    ↳ nucl-thhep-phPRC(2025)·0 citations
37. 37*

    Holographic QCD Matter: Chiral Soliton Lattices in Strong Magnetic Field

    Markus A.G. Amano🇯🇵 · Minoru Eto🇯🇵 · Muneto Nitta🇯🇵 · Shin Sasaki🇯🇵

    We investigate the chiral soliton lattice (CSL) in the framework of holographic QCD in magnetic field. Under appropriate boundary conditions for the gauge field and the quark mass deformation, we demonstrate that the ground state in the gravitational dual of QCD is given by the CSL in the background magnetic field and the baryon number density. In the presence of the background magnetic field, we show that the CSL is interpreted as a uniformly distributed D4-branes in the holographic setup, where the chiral soliton is identified with a non-self-dual instanton vortex or a center vortex in the five dimensional bulk gauge theory. While the baryon numbers are given to chiral solitons as well as Skyrmions due to the different terms in the Wess-Zumino-Witten (WZW) term in the chiral perturbation theory, these baryon numbers with different origins are unified in terms of the instanton charge density in five dimensions. With bulk analysis of the WZW term, we find that the pion decay constant becomes dependent on the magnetic field. For the massless pion case, we obtain an analytical form that is in qualitative agreement with lattice QCD results for strong magnetic fields.

    ↳ hep-thgr-qchep-phJHEP(2026)·10 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.