Thu·Apr 16, 2026Thursday·April 16, 2026

1. 01*

   Searching for axions with quantum interferometry

   Tanmay Kumar Poddar🇬🇧 · Michael Spannowsky🇩🇪

   Quantum phase measurements offer a complementary route to axion searches. We show that axion-photon interactions can imprint both Aharonov-Bohm (AB) and Berry phases in experimentally motivated quantum setups. For a coherently oscillating axion dark matter background, the induced effective current generates a time dependent magnetic flux in an rf-SQUID, leading to a measurable voltage signal through the Josephson phase. For representative benchmarks, this AB phase search reaches the minimum axion-photon coupling $g_{a\gamma \gamma }^{\min }\sim 7.8\times 10^{-14}{\mathrm{GeV}}^{-1}$ at axion mass $m_a\sim 10^{-10}\mathrm{eV}$, with projected sensitivity that can improve on existing limits in that parameter space by roughly one to two orders of magnitude. We also identify a geometric phase observable in a Mach-Zehnder interferometer with an adiabatically rotating magnetic field, providing a proof-of-principle phase-based probe of meV-scale axions even when they do not constitute the dark matter, although sensitivity on the coupling remains weaker than current bounds with conservative tabletop benchmarks. Extending the analysis to a three level photon-axion quasiparticle (AQP)-axion system, with the AQP realized in a topological magnetic insulator, we find a potentially measurable THz Berry phase dominated by the AQP sector, furnishing a nontrivial validation of the formalism in a richer coupled system. These setups establish quantum phase observables as a useful new framework for axion searches, with immediate phenomenological promise in superconducting circuits and longer term potential in quantum enhanced interferometry.

   hep-phastro-ph.CO1 citation
2. 02*

   Constraints on Vector-Like Top Dipole Interactions from Top-Associated Photon Measurements at the LHC

   Mohammad Sahraei · Yasaman Hosseini🇮🇷 · Mojtaba Mohammadi Najafabadi🇮🇷

   Vector-like top partners with electric charge $+2/3$ are predicted in many extensions of the Standard Model and are actively searched for at the LHC through their electroweak decays $T\to Wb$, $Zt$, and $Ht$. More general scenarios, however, allow dipole interactions that induce radiative decays $T\to t\gamma$ and $T\to tg$. We reinterpret precision measurements of top-associated photon production to constrain such dipole operators. This approach provides a complementary probe to traditional resonance searches, which rely on direct reconstruction of heavy states, by instead exploiting distortions in precision observables. Using unfolded differential cross sections for $t\bar{t}\gamma$ production measured by CMS and the fiducial $t\bar{t}\gamma \gamma$ cross section reported by ATLAS, we derive constraints on the electromagnetic and chromomagnetic dipole couplings of a vector like $T$ quark within an effective field theory framework. We present limits in terms of the effective couplings $c_{t\gamma }$ and $c_{tg}$, as well as the corresponding branching fractions $BR(T\to t\gamma )$ and $BR(T\to tg)$, for masses in the range $500GeV\le m_T\le 2.0TeV$. For $m_T=500GeV$, the analysis reaches sensitivity to the electromagnetic dipole coupling as small as $c_{t\gamma }\simeq 0.005Te{V}^{-1}$ in the gluon dominated scenario $B_{\gamma }=0.1$, while the sensitivity degrades to $O(1)Te{V}^{-1}$ at $m_T=2.0TeV$. We find that the $t\bar{t}\gamma$ and $t\bar{t}\gamma \gamma$ measurements provide complementary sensitivity, probing different regions of parameter space and lifting degeneracies between electromagnetic and chromomagnetic dipole interactions. These results demonstrate that precision measurements of top-associated photon final states provide a powerful and complementary probe of vector-like quarks in scenarios where radiative decays dominate.

   hep-ph0 citations
3. 03*

   A Core Representation Theorem for Scheme-Invariant Collinear Factorization in QCD

   Dustin Keller🇺🇸

   Collinear factorization and the leading-twist operator product expansion (OPE) in perturbative QCD express suitably inclusive observables in scale-separated kinematics as composites of perturbative short-distance coefficients with universal long-distance non-perturbative correlators such as parton distribution functions (PDFs), up to controlled power corrections. A persistent structural feature is \emph{presentation non-uniqueness}: coefficients and correlators are not individually physical, but are defined only up to finite factorization-scheme redefinitions induced by collinear subtractions and renormalized-operator mixing. We formalize this redundancy categorically by introducing an \emph{interface algebra object} encoding admissible finite collinear counterterms/mixing kernels and by organizing coefficient data and hadronic data as right/left modules over this algebra in a symmetric monoidal category encoding the chosen recomposition calculus. Our main result, the \emph{Core Representation Theorem}, identifies the universal scheme-invariant carrier: the functor of balanced (scheme-invariant) pairings is represented by the relative tensor product $C{\otimes }_{A}f$, which is terminal among all quotients of the naive composite $C\otimes f$ that preserve scheme-invariant semantics. Finally, we show how standard physics inputs (symmetry constraints, locality/OPE, and a stated accuracy truncation) canonically induce the interface algebra and module structures, and we prove a minimal closure principle for completing a generating set of long-distance operators/correlators to an $A$-stable sector.

   hep-phhep-th1 citation
4. 04*

   Sensitivity to top-quark FCNC interactions at future muon colliders

   A. Senol🇹🇷 · B. S. Ozaltay🇹🇷 · M. Tekin🇹🇷 · H. Denizli🇹🇷

   We investigate flavor-changing neutral current (FCNC) interactions of the top quark at a future muon collider operating at a center-of-mass energy of $\sqrt{s}=10\mathrm{TeV}$. The process ${\mu }^{+}{\mu }^{-}\to {\nu }_{\mu }{\mu }^{+}bj$ together with its charge-conjugate channel is considered as a probe of anomalous $tqZ$ and $tq\gamma$ interactions within a model-independent effective field theory framework. Starting from the most general FCNC Lagrangian, we examine the contributions of vector and tensor operators as well as the chiral structure of the anomalous interactions. Owing to the strong chiral suppression of the right-handed contributions at multi-TeV energies, the detector-level sensitivity analysis is performed for the left-handed tensor couplings. Signal and Standard Model background events are generated using a complete Monte Carlo simulation chain, including matrix-element generation, parton showering and hadronization with \texttt{Pythia}, and fast detector simulation with \texttt{Delphes} using a dedicated $10$~TeV muon collider detector card. Signal discrimination is optimized through a boosted decision tree (BDT) analysis employing an extended set of kinematic observables. Assuming an integrated luminosity of $10{\mathrm{ab}}^{-1}$, we derive projected exclusion and discovery sensitivities from a simultaneous two-dimensional scan of the real and imaginary components of the anomalous left-handed couplings ${\kappa }_{qt}^L$ and ${\lambda }_{qt}^L$. The obtained limits reach the $\mathcal{O}(10^{-3})$ level for the effective couplings, corresponding to branching-ratio sensitivities of $\mathcal{O}(10^{-6})$ for the rare decays $t\to qZ$ and $t\to q\gamma$. These projections improve the current experimental limits from the ATLAS and CMS collaborations by approximately one order of magnitude.

   hep-phhep-ex1 citation
5. 05*

   Axion Inflation from Heavy-Fermion One-Loop Effects

   Kai-Ge Zhang🇨🇳 · Jian-Feng He🇨🇳 · Chengjie Fu🇨🇳 · Zong-Kuan Guo🇨🇳

   We derive a one-loop effective description of axion inflation by integrating out a heavy Dirac fermion with an inflaton-dependent complex mass undergoing a smooth localized threshold transition. The threshold induces correlated corrections to the inflaton and gauge sectors, including a Coleman-Weinberg term, a vacuum-polarization correction, and an anomaly-induced Chern-Simons coupling. Together, these effects transiently enhance and localize gauge-field production, generating a chiral stochastic gravitational-wave background in the deci-hertz band within the projected sensitivities of BBO and DECIGO, while remaining below representative primordial-black-hole bounds.

   hep-phastro-ph.COgr-qc0 citations
6. 06*

   Global polarization of $\Lambda$ hyperons in hot QCD matter at TeV energies

   Bhagyarathi Sahoo🇮🇳 · Captain R. Singh🇮🇳 · Raghunath Sahoo🇮🇳

   The study of spin polarization of $\Lambda$ hyperons in ultrarelativistic heavy-ion collisions provides insights into the angular momentum and vortical structure of the possible existence of QGP. The present study examines the global spin polarization of $\Lambda$ hyperons using a second-order relativistic viscous hydrodynamic framework that incorporates medium vorticity, shear viscosity, and evolving magnetic fields. It explores thermal vorticity evolution in relativistic heavy-ion collisions and evaluates its value at the decoupling isothermal freeze-out surface. We quantify the contributions of thermal vorticity and magnetic field to the global spin polarization of $\Lambda$ hyperons. Comparing results with recent ALICE measurements in Pb+Pb collisions at $\sqrt{s_{NN}}$ = 2.76 and 5.02 TeV shows qualitative agreement, offering new insights into the vortical structure of QCD matter. It also explores the relationship between magnetic and rotational dynamics, with implications for spin polarization at RHIC and LHC energies.

   hep-phhep-exhep-thnucl-ex+11 citation
7. 07*

   Fully Heavy Pentaquarks with JETHAD: A High-Energy Viewpoint

   Francesco Giovanni Celiberto🇪🇸

   We examine the leading-power fragmentation of fully heavy pentaquarks in high-energy hadronic collisions. To this end, we complete the release of the hadron-structure-oriented PQ5Q1.0 fragmentation functions, by discussing the $P_{5c}$ set and delivering the $P_{5b}$ one. These functions incorporate an improved computation of the initial-scale input for the constituent heavy-quark fragmentation channel, making them particularly suitable for describing both the direct formation of a compact multicharm state and the hadronization from a diquark-antiquark-diquark configuration. For phenomenological applications, we employ the data-validated (sym)JETHAD framework to compute and analyze NLL/NLO${}^{+}$ semi-inclusive production rates of pentaquark-plus-jet systems at the upcoming HL-LHC and the future FCC. This study marks a further step toward connecting hadronic structure, precision QCD, and the emerging physics of exotic matter.

   hep-phhep-exhep-thnucl-ex+1Particles(2026)·9 citations
8. 08*

   A new approach to dark photon

   Jie Tang🇨🇳 · Pei-Hong Gu🇨🇳

   Over the past few decades, the hypothetically dark photon has been extensively studied from both phenomenological and experimental perspectives. It should be noted that the local symmetry for dark photon does not gauge the standard model Higgs scalar and chiral fermions. In this paper, we show that an artificially introduced $U(1{)}_X$ gauge group for dark photon and the standard model $U(1{)}_Y$ gauge group for hypercharge can be simultaneously born from two $U(1{)}_1\times U(1{)}_2$ gauge groups under which the standard model scalar and fermions carry the same $U(1{)}_1$ and $U(1{)}_2$ charges without causing any gauge anomalies. We further introduce a spontaneously broken mirror symmetry between the $U(1{)}_1$ and $U(1{)}_2$ gauge groups so that the $U(1{)}_1$ and $U(1{)}_2$ gauge couplings can acquire a small difference at one-loop level and hence the $U_X\times U_Y$ kinetic mixing can be highly suppressed in a natural way.

   hep-ph0 citations
9. 09*

   Torsion induced one-loop corrections to inflaton decay and the Stochastic gravitational waves

   AlexKen Lee🇪🇸 · Keyun Wu🇪🇸

   We investigate one-loop corrections from torsion-induced four-fermion interactions to inflaton three-body decay and their impact on the associated stochastic gravitational-wave signal. We find a pronounced asymmetry in the dependence on the renormalization scale $u$. While the enhancement of the gravitational-wave spectrum remains modest, not exceeding roughly a factor of order unity for representative inflaton masses well below the Planck scale within the perturbative regime, the suppression can be much stronger, reaching up to two orders of magnitude, corresponding to reductions at the percent level. These results imply that loop corrections, particularly fermionic self-interactions, can significantly reduce the predicted gravitational-wave signal in models based on tree-level analyses. This suppression may shift the signal outside the sensitivity range of future observations and should therefore be taken into account in realistic phenomenological studies.

   hep-phhep-th1 citation
10. 10*

    Refining two-loop corrections to trilinear Higgs couplings in the Two-Higgs-Doublet Model

    Johannes Braathen🇩🇪 · Felix Egle🇩🇪 · Alain Verduras Schaeidt🇩🇪

    The precise determination of the Higgs self-couplings is an essential task for understanding electroweak symmetry breaking and probing physics beyond the Standard Model (SM). The calculation of two-loop corrections to scalar couplings is important as it provides a critical test of the perturbative stability of the theoretical predictions, especially in scenarios with extended scalar sectors where large one-loop corrections can occur. Moreover, two-loop corrections need to be taken into account for the future perspective of precisely measuring the trilinear Higgs self-coupling. We present new results for the leading two-loop corrections to trilinear Higgs couplings in the Two-Higgs-Doublet Model (2HDM). We focus in particular on the couplings ${\lambda }_{hhh}$ and ${\lambda }_{hhH}$, which are relevant for Higgs pair production at the (HL-)LHC or at future linear colliders. We address the renormalisation of the alignment limit in the Higgs basis and give some insights into technical details of the calculation. Finally, we discuss the phenomenological impact of our results on di-Higgs production differential distributions.

    hep-phEur.Phys.J.Plus(2026)·5 citations
11. 11*

    A dynamical implementation of colour coherence for quenched jets in JEWEL

    Korinna Zapp🇸🇪

    Colour coherence affects the radiation pattern of hard partons both in vacuum and in a dense coloured background formed in heavy ion collisions. In vacuum evolution it leads to the well-known phenomenon of angular ordering, and in heavy ion collisions the appearance of a medium resolution scale strongly affects the way in which a fragmenting hard parton interacts with the background medium. In this paper I present the implementation of colour coherence in the JEWEL event generator for jet evolution in a dense medium. In each interaction between a hard parton and the medium it is checked whether the momentum transfer of the scattering is sufficient to resolve the colour dipole. In this way it is dynamically decided which structures stay coherent. Importantly, scatterings that resolve an individual parton disrupt the colour coherence, which affects the next splitting via the loss of angular ordering. This leads to a suppression of hard radiation, and consequently a reduction in overall scattering rate, which is the dominant source of effects of colour coherence observable in reconstructed jets. I discuss these modifications using the examples of nuclear modification factor, jet fragmentation function and jet-hadron correlations.

    hep-ph5 citations
12. 12*

    Resonance- and Width-aware Parton Shower Evolution and NLO Matching

    Stefan Höche🇺🇸 · Daniel Reichelt🇨🇭

    We introduce a technique for the next-to-leading order accurate simulation of $e^{+}{e}^{-}\to W^{+}{W}^{-}b\bar{b}$ that respects the resonant nature of the process above and near the top-quark pair production threshold. The parton-shower evolution, infrared subtraction and NLO matching account in particular for finite width effects beyond the Breit-Wigner structure considered in resonance-aware approaches. We present first phenomenological results relevant to a potential future electron-positron collider and provide a publicly available simulator based on the ALARIC parton shower and the SHERPA event generator.

    hep-ph2 citations
13. 13*

    Magnetic moments and radiative decay widths of doubly- and triply-heavy baryons in the dynamical heavy diquark model

    A. Armat🇮🇷 · S. Mohammad Moosavi Nejad🇮🇷

    The magnetic moments and radiative decay widths of heavy baryons belong to a class of interesting experimental observables which provide direct information about the dynamics of strong interactions as well as the properties and the composition structures of heavy baryons. In this work, through a diquark model we compute these two quantities for doubly and triply heavy baryons in a dynamical model. We, first, compute an analytical mass equation for heavy diquarks based on the Bethe-Salpeter equation in which the interaction potential between constituents includes the contributions from the Cornell, the Breit-Fermi approximation, the spin-spin terms and the tensor potential. By iterating the mass equation, we compute the masses and the wave functions of heavy baryons. We also compute the magnetic moments and the radiative decay width of double and triple heavy baryons in their ground state. Our results are compared with other model-dependent predictions and existing data. We will also predict the mass and the magnetic moment of unobserved triply heavy baryons relevant for the present and future high energy colliders.

    hep-phEPJC(2026)·0 citations
14. 14*

    Tests of Lorentz Symmetry using X-ray Polarimetry

    Fabian Kislat🇺🇸

    Lorentz symmetry is the fundamental symmetry of Einstein's theory of Special Relativity and has been tested to great precision. Nevertheless, the possibility remains that it is violated at the Planck scale, as predicted by some theories of quantum gravity. While the Planck scale is not directly accessible to experiments, minute residual deviations from Lorentz symmetry at attainable energies may be observable. The polarization of light from astrophysical sources is a particularly powerful probe because tiny differences accumulate as light travels over astrophysical distances, and polarization is sensitive to light travel time differences between polarization modes on the order of the oscillation period of the electromagnetic wave. Here, we report on new constraints on Lorentz invariance violation derived from X-ray polarization measurements of active galactic nuclei. The new constraints, presented in the framework of the Standard-Model Extension, improve on our previous work, which used optical polarization measurements, by four orders of magnitude.

    hep-ph0 citations
15. 15*

    The origin of Bjorken-$x$ dependence in DIS: a case for a $z$-dependent correlator in the CGC

    Benjamin Guiot🇨🇱

    We discuss an inconsistency of the eikonal Color Glass Condensate (CGC) description of Deep Inelastic Scattering (DIS). In this framework, the Bjorken-$x$ dependence enters the cross section solely through the rapidity cutoff $\Lambda =x_b$, leading to an all-order cross section independent of $x_b$. To address this issue, we explore a natural modification in which the CGC correlators depend explicitly on the light-cone momentum fraction $z$, with integration limits determined by $x_b$. This modification is consistent with the physical expectation that the observed non-perturbative structure depends on the probe energy. Our analysis implies that the (small-)$x_b$ variation of the cross section is not solely driven by small-$x$ evolution equations. We support this conclusion through an analysis of existing DIS fits and by demonstrating that a similarly good description of the data can be obtained within the modified framework. Finally, we show that the modified formulation is compatible with $k_t$-factorization, unlike the standard one.

    hep-ph0 citations
16. 16*

    Exploring new resonances with direct top flavor changing interactions

    Min Huang🇨🇳 · Yandong Liu🇨🇳 · Hao Zhang🇨🇳

    In this work, we investigate three typical new physics resonances which couple to the standard model (SM) quarks via direct top-quark flavor-changing interactions. We identify the possible SMEFT operators electroweak scale and analyze their phenomenology.

    hep-phhep-exCPC(2026)·0 citations
17. 17*

    Electro-Weak Phase Transitions and Collider Signals in the Aligned 2-Higgs Doublet Model

    Angela Conaci🇮🇹 · Stefania De Curtis🇮🇹 · Luigi Delle Rose🇮🇹 · Atri Dey🇸🇪 · Anirban Karan🇮🇹 · Stefano Moretti🇬🇧 · Maimoona Razzaq🇮🇹

    We show that the Aligned 2-Higgs Doublet Model (A2HDM) is a framework able to simultaneously accommodate strong first order electro-weak phase transitions, in turn generating detectable gravitational waves as well as a variety of Higgs boson signals (involving both the Standard Model state and its companions, both neutral and charged) accessible at the Large Hadron Collider (LHC). We map the corresponding expanse of parameter space where such a phenomenology is realised in terms of the relative values of the masses of the discovered Higgs boson and the extended Higgs sector states of this model: two neutral ones (a CP-even and a CP-odd) plus a pair of charged ones. We find that both the Laser Interferometer Space Antenna experiment and High-Luminosity LHC can test such a scenario within their lifetime. This study thus sets the stage for a two-prong complementary approach able to scrutinise the extended Higgs sector of the A2HDM in both its high and low temperature manifestations.

    hep-phastro-ph.CO3 citations
18. 18*

    AI-assisted modeling and Bayesian inference of unpolarized quark transverse momentum distributions from Drell-Yan data

    Zhong-Bo Kang🇺🇸 · Luke Sellers🇺🇸 · Congyue Zhang🇺🇸 · Curtis Zhou🇺🇸

    We present an extraction of unpolarized quark transverse-momentum-dependent parton distribution functions (TMD PDFs) from Drell-Yan data within a Bayesian inference framework, incorporating artificial intelligence at multiple stages of the analysis. Our analysis is performed at ${\mathrm{N}}^3\mathrm{LO}$ in perturbative QCD combined with ${\mathrm{N}}^4\mathrm{LL}$ resummation accuracy. We first employ an AI-driven iterative procedure to explore and rank candidate functional forms for the nonperturbative contributions to TMD PDFs at the initial scale, as well as for the Collins-Soper evolution kernel, using ${\chi }^2$ fits and physics constraints. To enable efficient Bayesian inference, we construct a surrogate model for TMD cross sections by training a machine-learning emulator over the parameter space, replacing computationally expensive repeated evaluations and allowing scalable sampling with an affine-invariant Markov Chain Monte Carlo (MCMC) ensemble. Using this framework, we perform a global analysis of Drell-Yan data from fixed-target, RHIC, and LHC experiments and extract TMD PDFs with quantified uncertainties. We compare the results with those obtained using the replica method and highlight differences in the resulting uncertainty estimates.

    hep-phhep-exnucl-exnucl-th5 citations
19. 19*

    The Spurion Massive EFT (SMEFT)

    Julian L. Northey🇮🇱 · Yael Shadmi🇮🇱 · Yotam Soreq🇮🇱 · Daiki Ueda🇮🇱

    We use the amplitude formulation of the SMEFT to introduce a spurion analysis of the SMEFT low-energy amplitudes in terms of the Higgs VEV. Each SMEFT contact-term is given as a sum of a few spurion structures, whose number depends on the electroweak charges of the external legs. The coefficients of these structures involve singlet combinations of Higgses from higher-order SMEFT contributions. We use this to derive the spurion expansions of the W- and Z-boson masses and mixing, and their three-point couplings to fermions. The textures of these couplings are saturated by the dimension-eight SMEFT. Our analysis can be generalized to higher-point amplitudes and nonzero Yukawa couplings.

    hep-phhep-thJHEP(2026)·0 citations
20. 20*

    Probing $\tau$ lepton dipole moments at future Lepton Colliders

    Dario Buttazzo🇮🇹 · Gabriele Levati🇨🇭 · Yang Ma🇧🇪 · Fabio Maltoni🇧🇪 · Paride Paradisi🇮🇹 · ZeQiang Wang🇧🇪

    The electric and magnetic dipole moments of the electron and of the muon provide stringent tests of the Standard Model and sensitive probes of new physics. By contrast, the corresponding dipole moments of the $\tau$ lepton remain weakly constrained. This study explores the potential of future lepton colliders, focusing on the $e^{+}{e}^{-}$ Future Circular Collider and a multi-TeV muon collider, to probe $\tau$ dipole moments. We consider multiple channels, including ${\ell }^{+}{\ell }^{-}\to {\tau }^{+}{\tau }^{-}$ ($\ell =e,\mu$), associated Higgs production ${\mu }^{+}{\mu }^{-}\to {\tau }^{+}{\tau }^{-}H$, radiative Higgs decays $H\to {\tau }^{+}{\tau }^{-}\gamma$, and vector-boson scattering ${\ell }^{+}{\ell }^{-}\to {\ell }^{+}{\ell }^{-}{\tau }^{+}{\tau }^{-}$ and ${\mu }^{+}{\mu }^{-}\to \bar{\nu }\nu {\tau }^{+}{\tau }^{-}$. Our results show that these facilities are highly complementary and can extend existing bounds by several orders of magnitude.

    hep-phhep-ex8 citations
21. 21*

    Probing Neutrino Compositeness with Invisible and Displaced Signals

    Matteo Borrello🇮🇹 · Marco Costa🇨🇦 · Diego Redigolo🇮🇹 · Michele Tammaro🇮🇹

    We explore the possibility that neutrinos couple to an interacting sterile sector, providing a novel portal that generalizes the heavy neutral lepton portal to a composite setting. For a low confinement scale, high-energy neutrino beams can disintegrate into collimated sprays of hidden states, referred to as dark jets. This dynamics gives rise to two characteristic signatures in high energy neutrino beams. First, long-lived dark resonances can enhance the neutral-current to charged-current ratio. Second, shorter-lived dark states produced in neutrino neutral currents can produce single or multiple displaced vertices and even emerging jets, depending on the kinematics. These signals probe regions of parameter space beyond existing constraints from meson, electroweak, and Higgs decays, as well as from searches for displaced decays at beam dump experiments. We study these phenomena within broad classes of ultraviolet completions and identify scenarios in which high-energy neutrino beams provide leading sensitivity to neutrino compositeness. Such scenarios generically induce higher-dimensional contact interactions, which we classify and study alongside their complementary experimental signatures. Finally, we outline an experimental program spanning both the intensity and energy frontiers. Near-term neutrino facilities (DUNE, FPF) and running flavor experiments (LHCb, Belle II) can probe neutrino compositeness through neutrino disintegration into dark jets and displaced B-meson decays. Future colliders, particularly the Future Circular Collider (FCC-ee), will ultimately provide the strongest sensitivity to the compositeness scale via displaced Z decays.

    hep-ph1 citation
22. 22*

    A Busy Higgs Signal

    Peiran Li🇺🇸 · Zhen Liu🇺🇸 · Lian-Tao Wang🇺🇸

    Higgs final states are prime targets in the search for physics beyond the Standard Model. In the conventional picture, $SU(2)$ symmetry together with the Goldstone Equivalence Theorem correlates Higgs and gauge-boson final states, implying comparable sensitivity in channels such as $hh$, $ZZ$, and $WW$ in searches for heavy resonances. In this work, we identify a mechanism to parametrically violate this expectation. We show that higher-order Higgs couplings can induce an electroweak-symmetry-breaking enhancement that selectively amplifies Higgs-rich final states, allowing them to become the leading discovery channels of new resonances. For scalar resonances, this can make di-Higgs the dominant bosonic signal. For resonance masses higher than a couple of TeV, it also opens resonant tri-Higgs and four-Higgs channels as well-motivated search targets. The same underlying mechanism extends to heavy fermionic and vector resonances, where it can similarly enhance channels such as $ht$, $Zh$, and $\gamma h$. We present this framework in effective field theory, demonstrate possible UV completions, and discuss its implications for collider searches.

    hep-ph3 citations
23. 23*

    Cornering MeV-GeV Axions and Dark Photons with LDMX

    Sarah Gaiser🇺🇸 · Alessandro Russo🇺🇸 · Philip Schuster🇺🇸

    Axion-like particles (ALPs), the QCD axion, and dark photons in the MeV-GeV mass range are motivated by various dark matter models and the strong CP problem, and are ubiquitous in extensions of the Standard Model. A long-standing blind spot for experimental searches is the sub-100 MeV mass range, where the particle lifetime is too long to be constrained by prompt-decay collider searches yet too short to be reached by beam-dump experiments. We investigate and estimate the sensitivity of the Light Dark Matter eXperiment (LDMX) to such axions and dark photons, motivated by the clean environment in which these particles can be produced and by the near-target tracking capabilities of LDMX. With reasonable charged track and momentum reconstruction capabilities, we find that LDMX could close much of this low-mass blind spot for axions and dark photons.

    hep-phhep-exhep-th1 citation
24. 24*

    Heavy baryons with relativistic quarks

    Archana Radhakrishnan🇮🇳 · Debsubhra Chakraborty🇮🇳 · Nilmani Mathur🇮🇳

    We present a lattice QCD study of heavy baryons containing charm and bottom quarks, with particular emphasis on the relativistic treatment of all valence quarks. We use $N_f=2+1+1$ HISQ ensembles at the physical point to compute ground-state energies of spin-$3/2^{+}$ baryons, including singly-, doubly-, and triply-heavy charmed and bottom baryons. This work represents the first investigation of heavy baryons using fully relativistic bottom quarks.

    ↳ hep-lathep-phPoS(2026)·1 citation
25. 25*

    Four-loop Anomalous Dimensions of Scalar-QED Theory from Operator Product Expansion

    Rijun Huang🇨🇳 · Qingjun Jin🇨🇳 · Yi Li🇨🇳

    We apply the Operator Product Expansion (OPE) algorithm to the renormalization of scalar-QED theory, with a specific focus on the fixed-charge operator ${\varphi }^Q$. Within the OPE framework, the anomalous dimension of the ${\varphi }^Q$ operator is perturbatively computed to four-loop order in the modified minimal subtraction scheme, extending beyond the previously available three-loop result. The beta functions, as well as the mass and field anomalous dimensions, are also computed at this order. An alternative loop-integrand construction method is proposed, based on graph decomposition and skeleton expansion techniques, for deriving the integrands of one-Particle-Irreducible correlation functions. This work represents the first non-trivial validation of the OPE algorithm for higher-loop renormalization beyond pure scalar theories. The present successful computations further confirm the efficiency and versatility of the OPE algorithm in renormalization analysis.

    ↳ hep-thhep-ph1 citation
26. 26*

    Double the axions, half the tension: multi-field early dark energy eases the Hubble tension

    Marco Bella🇮🇹 · Vivian Poulin🇫🇷 · Sunny Vagnozzi🇮🇹 · Lloyd Knox🇺🇸

    We show that the strong constraints placed by Planck NPIPE Cosmic Microwave Background (CMB) data on axion-like early dark energy (EDE) are significantly alleviated in models with multiple fields. We find a $1.5\sigma$ residual tension with the Local Distance Network value of $H_0$ in a 2-field model, with no improvement beyond two fields, and a best-fit value of $H_0$ $\sim 1.4\sigma$ larger than in the 1-field case. The second field improves the fit to high-$\ell$ CMB data, where 1-field EDE is most strongly disfavored, and suggests modifications to the pre-recombination history over a wider redshift range.

    ↳ astro-ph.COgr-qchep-ph22 citations
27. 27*

    Fast Neutrino-Flavor Conversion with Attenuation and Global Lepton Gradient

    Masamichi Zaizen🇯🇵 · Hiroki Nagakura🇯🇵

    Fast neutrino-flavor conversion (FFC) can nontrivially alter neutrino radiation field in core-collapase supernovae (CCSN) and binary neutron-star merger (BNSM) remnants. However, its interplay with global geometry remains poorly understood because microscopic flavor conversion scales are much shorter than global transport scales. We perform global quantum kinetic neutrino transport simulations in spherical geometry with neutrino and matter backgrounds, using an attenuated oscillation Hamiltonian. We find that steep radial lepton gradients can suppress FFC, whereas the suppression is highly sensitive to the adopted attenuation parameter. This behavior is explained by an adiabatic condition: flavor coherence can grow sufficiently only while the flavor wave remains on the unstable branch in the local dispersion relation during propagation. Background variation shifts the unstable branch, while attenuation lengthens the growth timescale, making the flavor coherence following more difficult. We provide an approximate formula for the adiabaticity that can be used directly in CCSN and BNSM models developed by classical neutrino transport simulations. Our results show that attenuation artificially leads to an overestimation of the impact of background variation and should therefore be applied with caution in global simulations of neutrino flavor conversion.

    ↳ astro-ph.HEhep-ph6 citations
28. 28*

    Manipulation of Superposed Vortex States of $\gamma$ Photon via Nonlinear Compton Scattering

    Jun-Lin Zhou🇨🇳 · Mamutjan Ababekri🇨🇳 · Yong-Zheng Ren🇨🇳 · Yu Wang🇨🇳 · Ren-Tong Guo🇨🇳 · Zhao-Hui Chen · Yu-Han Kou🇨🇳 · Zhong-Peng Li🇨🇳 · Jian-Xing Li🇨🇳

    Vortex $\gamma$ photons in superposition states have important applications in photonuclear, high-energy, and strong-field physics. However, their controlled generation in the $\gamma$-ray regime remains a great challenge. Here, we put forward a novel method for the generation of vortex $\gamma$ photon in superposition states, with controllable orbital angular momentum (OAM) separation $\Delta {\ell }^{\prime }$ and modal weights, via nonlinear Compton scattering driven by multifrequency circularly polarized laser fields. We develop a strong-field quantum electrodynamics (QED) framework to reveal the underlying mechanism and calculate the radiation probabilities. In our method, the superposition arises from interference between energy-degenerate multiphoton pathways carrying distinct OAM. For two-frequency fields, the OAM separation follows $\Delta {\ell }^{\prime }=\nu \mp 1$ (upper/lower sign for equal/opposite helicities), and modal weights are tunable by laser intensities, with $\nu$ the frequency ratio. Vortex $\gamma$ photons in controllable superposition states from our method have significant applications in strong-field QED and nuclear photonics.

    ↳ quant-phhep-phphysics.optics0 citations
29. 29*

    Dark energy, spatial curvature, and star formation efficiency from JWST photometric and spectroscopic high-redshift galaxies

    Leonardo Comini🇮🇹 · Sunny Vagnozzi🇮🇹 · Abraham Loeb🇺🇸

    Early observations from the James Webb Space Telescope (JWST) have revealed an overabundance of massive high-redshift galaxies, raising the question of whether this points to new physics beyond $\Lambda$CDM, or an enhanced formation efficiency of massive stars. We revisit this issue going beyond earlier analyses based on direct comparisons to theoretical bounds at a fixed cosmology, by performing a full Bayesian analysis of the most extreme galaxies in the CEERS imaging and FRESCO spectroscopic samples, jointly constraining cosmological parameters and the baryon-to-star conversion efficiency $ϵ$. We do so not only within the spatially flat $\Lambda$CDM model, but also in models where the dark energy equation of state $w$ and/or the spatial curvature parameter ${\Omega }_K$ are allowed to vary, carefully discussing the impact of both $w$ and ${\Omega }_K$ on the cumulative comoving stellar mass density. Within the flat $\Lambda$CDM model, once cosmological parameters are marginalized over, the CEERS sample provides a weak $2\sigma$ lower limit of $ϵ\gtrsim 0.07$, compatible with astrophysical expectations. In contrast, the FRESCO sample requires $ϵ\gtrsim 0.5$ at $2\sigma$, with values $ϵ\lesssim 0.2$ disfavored at $>5\sigma$. These results do not qualitatively change when we allow $w$ and/or ${\Omega }_K$ to vary, with no evidence for deviations from $w=-1$ or ${\Omega }_K=0$. Our results therefore suggest that the origin of the ``JWST tension'' is unlikely to be cosmological, but lies in the astrophysics of galaxy formation.

    ↳ astro-ph.COastro-ph.GAgr-qchep-phJHEAp(2026)·6 citations
30. 30*

    Robust parameter inference for Taiji via time-frequency contrastive learning and normalizing flows

    Tian-Yang Sun🇨🇳 · Bo Liang🇨🇳 · Ji-Yu Song🇨🇳 · Song-Tao Liu🇨🇳 · Shang-Jie Jin🇨🇳 · He Wang🇨🇳 · Ming-Hui Du🇨🇳 · Jing-Fei Zhang🇨🇳 · Xin Zhang🇨🇳

    Transient noise artifacts, commonly referred to as glitches, pose a major challenge to parameter inference for space-based gravitational-wave (GW) observations. We develop a glitch-robust amortized inference framework for massive black hole binaries in the Taiji detector configuration by combining conditional normalizing flows, a time-frequency multimodal fusion encoder, and contrastive learning. To enable large-scale training on contaminated data, we further introduce a neural glitch generator that produces high-fidelity synthetic transients at substantially reduced computational cost. Systematic experiments show that, under glitch contamination, the proposed method yields more accurate and better-calibrated posteriors than a conventional Markov Chain Monte Carlo baseline. In ablation studies, the full time-frequency model with contrastive learning performs best overall and remains robust to variations in glitch duration and merger-relative timing. We further show that standard coverage diagnostics alone are insufficient to fully assess posterior fidelity. We therefore complement them with the continuous ranked probability score, which provides a stricter assessment of global distributional agreement in non-ideal GW data. Taken together, these results establish deep-learning-based amortized inference as a promising framework for fast and robust Bayesian parameter estimation in future space-based GW observations.

    ↳ gr-qcastro-ph.COhep-phhep-th4 citations
31. 31*

    Correlation between Ultrahigh-Energy Neutrino KM3-230213A and Gamma-Ray Bursts

    Ruiqi Wang🇨🇳 · Bo-Qiang Ma🇨🇳

    The KM3NeT Collaboration reported the detection of a neutrino, designated as KM3-230213A, with a reconstructed energy peaking at 220 PeV and equatorial coordinates (J2000) of RA=$94.3°$ and Dec=$-7.8°$. As the highest-energy neutrino event documented to date, its astrophysical origin remains unascertained. Prior preliminary investigations have probed potential associations between this neutrino event and gamma-ray bursts (GRBs), factoring in the possibility of Lorentz invariance violation (LV). In this study, we perform a comprehensive analysis to explore correlations between KM3-230213A and all viable GRBs. We explicitly account for the angular uncertainties intrinsic to both the neutrino event and the respective GRBs. Our analysis identifies a larger set of correlated GRBs. For each associated GRB, we compute the LV scale, integrating uncertainties from redshift measurements and neutrino energy determinations to enhance the robustness of our findings.

    ↳ astro-ph.HEgr-qchep-phApJ(2026)·0 citations
32. 32*

    Gravitational Sommerfeld Effects: Formalism, Renormalization, and Perturbation to $O(G^{10})$

    Chih-Hao Chang🇹🇼 · Chia-Hsien Shen🇹🇼 · Zihan Zhou🇺🇸

    In the effective field theory (EFT) description of binary inspirals, the radiated gravitational waveform receives universal corrections from the curved background, the so-called ``tail effects'', that resum into the so-called ``Sommerfeld factor''. We develop a systematic framework for computing this gravitational Sommerfeld factor for scalar perturbations with the presence of tidal effects on the system. Using the worldline EFT, we recast the diagrammatic resummation as a solution to the $d$-dimensional wave equation with a localized source, and derive a closed-form expression for the Sommerfeld factor in terms of the EFT connection matrix. We prove that the phase of the Sommerfeld factor is exactly the same as elastic Compton scattering phase shift when there is no tidal dissipation. By combining the renormalization techniques in EFT with the Mano--Suzuki--Takasugi method in black hole perturbation theory, we analytically solve the Sommerfeld factor for both the magnitude and phase to $O(G^{10})$ for the $\ell =0,1,2$ partial waves. We further establish a new renormalization group equation for the radiative multipole moments, whose exact solution yields an improved resummation of the waveform beyond the universal tail logarithms. These high-precision data and exact relations pave the way for future waveform resummation.

    ↳ hep-thastro-ph.HEgr-qchep-ph6 citations
33. 33*

    All-order structure of static gravitational interactions and the seventh post-Newtonian potential

    Giacomo Brunello🇮🇹 · Manoj K. Mandal🇮🇹 · Pierpaolo Mastrolia🇮🇹 · Raj Patil🇩🇪 · Matteo Pegorin🇮🇹 · Sid Smith🇮🇹 · Jan Steinhoff🇩🇪

    We present a closed formula for the computation of static post-Newtonian corrections to the two-body gravitational dynamics at any odd order, assuming the lower-order results are known. The formula is derived within a correlation function framework and exploits the ${\mathbb{Z}}_2$ symmetry of the static sector, leading to a novel theoretical interpretation of the factorization theorem. As an application, we compute the gravitational interaction of two compact coalescing objects at the seventh post-Newtonian order in the static limit, which receives contributions from seven-loop graphs at order $\mathcal{O}(G_N^8{v}^0)$, and find complete agreement with the results obtained using the diagrammatic approach of the factorization theorem.

    ↳ hep-thgr-qchep-ph10 citations
34. 34*

    Beyond the Dilute Instanton Gas: Resurgence with Exact Saddles in the Double Well

    Aurélien Dersy🇺🇸 · Matthew D. Schwartz🇺🇸

    The path-integral approach to the double well has long been limited by the dilute instanton gas approximation. We show that if the finite Euclidean-time structure is taken seriously by using exact saddles, the dilute gas can be sidestepped, allowing the partition function and energy levels to be computed systematically. At each instanton order, the full resurgent structure -- which saddles contribute, what asymptotic growth is expected and how ambiguities cancel -- is encoded in a finite-dimensional Picard--Lefschetz contour integral over the quasi-zero modes with a clear geometric interpretation. Working at finite $T$ is essential: the dilute instanton gas can only access the ground-state splitting, whereas the exact finite-$T$ computation systematically produces the non-perturbative energy splittings for all excited states, including their full dependence on the level number. The key ingredients -- Weierstrass elliptic functions for the saddles, Lamé operators for the fluctuations and Picard--Fuchs equations for the periods -- form a coherent mathematical framework that both overlaps and complements that of Exact WKB.

    ↳ hep-thhep-ph2 citations
35. 35*

    Quantum correction to the diffusion term in stochastic inflation from composite-operator matching in Soft de Sitter Effective Theory

    Martin Beneke🇩🇪 · Patrick Hager🇨🇭 · Andrea F. Sanfilippo🇪🇸

    In the framework of Soft de Sitter Effective Theory (SdSET), the Fokker-Planck equation for the late-time dynamics of the massless minimally coupled scalar field and its extension to the Kramers-Moyal equation are obtained from operator mixing of composite operators of the effective superhorizon field. We construct the formalism for composite-operator renormalisation, mixing and matching in dimensional regularisation, allowing for computations beyond the leading order. The general formalism is illustrated in free SdSET, which already features non-trivial structures including the well-known diffusion coefficient for stochastic inflation. As explicit examples in the interacting theory, we renormalise the one-loop bispectrum and the two-loop one-point function of the composite operator ${\phi }_{+}^2$, and match them onto their full-theory counterparts. These results allow us to determine the next-to-leading order (two-loop) correction to the diffusion term of the Fokker-Planck equation of stochastic inflation for the first time.

    ↳ hep-thastro-ph.COhep-ph7 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.