Tue·Jun 9, 2026Tuesday·June 9, 2026

1. 01*

   B Meson Semi-Invisible Decays via Perturbative QCD

   Han-Bing Liu🇨🇳 · Ye Xing🇨🇳 · Bin Luo🇨🇳

   This paper focuses on the dark sector decay processes of $B$ mesons ($B\to {\mathcal{B}}_8+$ invisible). Using the perturbative QCD (pQCD) approach combined with flavor symmetry analysis, we calculate the branching ratios for decays from $B$ mesons into light baryons and dark baryons within two distinct $B$-Mesogenesis scenarios. A detailed discussions of the form factor $B\to {\mathcal{B}}_8$ are presented. Based on the derived form factors and effective couplings, we then reach the final numerical analysis. The results show that the branching ratios are sizable, especially for $B^0\to \Lambda \psi$ and $B_s^0\to {\Xi }^0\psi$ in Type-I model, with values on the order of $\mathcal{O}(10^{-5})$ . Such processes are expected to facilitate the search for dark matter at hadron colliders and B factories.

   hep-ph0 citations
2. 02*

   Maximal Abelian Flavor Symmetries

   Juanca Carrasco-Martinez🇺🇸 · Lawrence J. Hall🇺🇸

   A framework, MAFS, is introduced that provides an approximate description of the hierarchies of quark and lepton masses and mixing angles in terms of a set of small parameters, ${ϵ}_a$, one for each fermion multiplet. MAFS is an alternative to the Froggatt-Nielsen mechanism and has a unique application in any theory, as there are no fermion charges to choose. It becomes more powerful as the number of multiplets is reduced. In $SU(5)$ unified theories, 15 observed mass ratios and mixing angles are described, at the factor of two level, by five small ${ϵ}_a$ parameters. Even though quarks and leptons are unified, the observed hierarchical pattern of quark masses and mixings {\it requires} large neutrino mixing angles and small neutrino mass hierarchies. In an $SO(10)$ unified theory, MAFS successfully describes the 15 observed flavor hierarchies with just three small ${ϵ}_a$, taking values of $0.01,0.02$ and $0.002$. The observed cosmological baryon asymmetry results approximately from leptogenesis using MAFS in $SU(5)$, without the need for any additional small parameter; while in $SO(10)$, a further small parameter of about 0.2 appears necessary.

   hep-ph2 citations
3. 03*

   First determination of vector and tensor couplings from polarized $\pi \Delta$ photoproduction

   Vanamali Shastry🇺🇸 · Łukasz Bibrzycki🇵🇱 · Vincent Mathieu🇪🇸 · Glòria Montaña🇪🇸 · Alessandro Pilloni🇮🇹 · César Fernández-Ramírez🇪🇸 · Robert J. Perry🇺🇸 · Arkaitz Rodas🇺🇸 · Adam P. Szczepaniak🇺🇸 · Daniel Winney🇲🇽

   The couplings between hadrons encode the dynamics of quantum chromodynamics. While many couplings can be calculated from decay widths, in some cases the decays are kinematically forbidden and hence are not directly accessible. We use a Regge framework to determine these couplings from high-energy polarized scattering processes. We apply this to the $\pi \Delta$ photoproduction that was recently studied at GlueX and provide the first determination of the complete set of $N\Delta$ couplings to $\rho$, $b_1$, and $a_2$.

   hep-phnucl-th1 citation
4. 04*

   Earth-Density Stratification and Quantum Gravity Corrections in Long-Baseline Neutrino Oscillation Experiments

   Bipin Singh Koranga🇮🇳 · Vivek Kumar Nautiya🇮🇳

   We present the first unified study of Earth matter-density stratification and Planck-scale quantum-gravity effects in long-baseline neutrino oscillations, treating both as correlated systematic uncertainties within a full three-flavor framework. Neutrino propagation is computed using matrix exponentiation with spatially resolved Preliminary Reference Earth Model (PREM) density profiles, allowing a quantitative assessment of matter-profile effects beyond the constant-density approximation. We find that the resulting bias in the reconstructed CP-violating phase remains below 0.3{\deg} for baselines (L \lesssim 5000) km, but increases to 17.8{\deg} at (L=7000) km and 172.2{\deg} at (L=12000) km, leading to a potential sign reversal of the inferred CP violation. We further incorporate Planck-scale corrections through the unique gauge-invariant dimension-5 operator of the Standard Model effective field theory. For quasi-degenerate neutrino masses ((m \sim 2) eV), the solar mass-squared splitting receives a correction of order ((1.0 \pm 0.5)\times10^{-5},\mathrm{eV}^2), while the atmospheric splitting remains essentially unchanged. Most importantly, we identify a previously unexplored degeneracy regime in which Planck-scale perturbations can partially compensate matter-induced biases. Around (L\approx7000) km, specific Majorana phases reduce the combined bias by about 30%, demonstrating that the two effects cannot be treated independently. These results highlight the necessity of propagating both Earth-density and quantum-gravity uncertainties as correlated systematics in precision measurements of leptonic CP violation.

   hep-ph1 citation
5. 05*

   Retarded Correlators of Charge Transport in a Magnetic Field

   Xuan Zhao🇨🇳 · Qiuze Sun🇨🇳 · Yi Wang🇨🇳 · Jin Hu🇨🇳

   We study charge transport in a magnetized relativistic plasma using kinetic theory within the relaxation-time approximation. By exactly solving the linearized Boltzmann equation in a uniform magnetic field, we obtain an analytic solution for the distribution function in terms of Bessel functions. Using this solution, we compute the full set of retarded current-current correlators and verify the Ward identities. In the hydrodynamic limit, we extract the charge diffusion modes, demonstrating that the transverse diffusion coefficient is strongly suppressed by the magnetic field, scaling as $1/B_0^2$ in the strong-field regime, while the longitudinal diffusion remains unaffected. Furthermore, we analyze the non-hydrodynamic branch cuts in the complex frequency plane, determining their kinematic thresholds and identifying the underlying wave-particle interactions as longitudinal Landau damping and transverse cyclotron damping.

   hep-phcond-mat.stat-mechhep-thnucl-th+11 citation
6. 06*

   A New Route to the Annihilation of Multi-Wall String Topological Configurations

   Utsav Atta🇮🇳 · Tathagata Ghosh🇮🇳 · Sudip Manna🇮🇳

   Particle physics models beyond the Standard Model often contain global symmetries to address various unanswered questions. However, a common criticism of theories based on global symmetries is that such symmetries are generally expected to be explicitly violated by gravitational effects at the Planck scale. In the case of a global $U(1)$ symmetry, this explicit breaking can reduce the symmetry to a discrete subgroup of $U(1)$, leading to the formation of cosmic strings attached to multiple domain walls (DWs). These DWs are usually cosmologically problematic, since their slow scaling behavior can eventually dominate the energy density of the Universe, giving rise to the well-known cosmological DW problem, which is strongly constrained by Big Bang Nucleosynthesis. In this letter, we propose a new annihilation mechanism of such DWs in theories with the simplest continuous global symmetry, $U(1)$, in the presence of gravitational effects. The mechanism is as follows: if a fermion coupled to the symmetry-breaking scalar possesses a small bare mass term, radiative corrections can generate a temperature-dependent bias for triggering DW annihilation. As a representative example, we study a majoron framework containing right-handed neutrinos with small bare mass terms, in which a wall-string network can arise once gravitational effects are taken into account. Within this setup, we show that the small bare masses of the right-handed neutrinos provide the origin of the bias responsible for triggering the annihilation of the DW network.

   hep-phastro-ph.COgr-qchep-th0 citations
7. 07*

   Anisotropic surface tension and stability of quark matter modified by the vector interaction

   Yu-Ying He🇨🇳 · Xin-Jian Wen🇨🇳

   In this article, the surface tension and stability of quark matter modified by the vector interaction in a strong magnetic field are investigated in the quasiparticle model with the multiple reflection expansion. The self-consistent thermodynamic treatment of the chemical-potential-dependent quark mass is maintained by the effective bag function, which depends on both the chemical potential and the magnetic field. It is found that the vector interaction could enlarge the surface tension in both the parallel and transverse directions with respect to the magnetic field. In a stronger magnetic field region, the presence of the vector repulsive interaction leads to an increase in transverse surface tension with the magnetic field strength, which is opposite to the vanishing value without repulsive interaction in the previous work. Consequently, it is concluded that a moderate-intensity magnetic field is required for the formation of a quark matter bubble with the vector interaction. Finally, it is demonstrated that the vector interaction slightly reduces the stability of quark matter.

   hep-phPRC(2026)·0 citations
8. 08*

   Impact of $N^{\ast }$ and ${\Lambda }^{\ast }$ resonances on $CP$ violation in ${\Lambda }_b^0$ decays

   Yu-Kuo Hsiao🇨🇳 · Kai-Lei Wang🇨🇳 · Juan Wang🇨🇳

   The four-body decay ${\Lambda }_b^0\to p{K}^{-}{\pi }^{+}{\pi }^{-}$ has led to the first observation of baryonic $CP$ violation. However, the underlying subprocesses ${\Lambda }_b^0\to N^{\ast }M$ and ${\Lambda }_b^0\to {\Lambda }^{\ast }M$, as well as the roles of excited nucleon ($N^{\ast }$) and hyperon (${\Lambda }^{\ast }$) resonances, remain largely unexplored. Within the constituent quark model, we identify the relevant resonant states contributing to these underlying two-body transitions, including $N(1535)$, $N(1520)$, $\Lambda (1670)$, $\Lambda (1690)$, together with the remaining $1P$-wave baryon states. We obtain the resonant branching fraction $\mathcal{B}({\Lambda }_b^0\to p{K}^{-}{\pi }^{+}{\pi }^{-})=(30.0_{-1.3-3.4}^{+2.8+4.0}\pm 1.8)\times 10^{-6}$, while the resulting ${\mathcal{A}}_{CP}({\Lambda }_b^0\to p{K}^{-}{\pi }^{+}{\pi }^{-})=(3.18\pm 0.11\pm 0.13\pm 0.11)\%$ provides a natural interpretation of the first observed baryonic $CP$ asymmetry. Our analysis establishes the first comprehensive framework for quantifying the impact of excited baryon resonances in multi-body beauty-baryon decays, with the associated mechanism generally applicable to baryonic $CP$ asymmetries.

   hep-phhep-ex0 citations
9. 09*

   Electron-muon colliders at high energies to discover heavy sterile neutrinos

   Gorazd Cvetič🇨🇱 · Claudio Dib🇨🇱 · C. S. Kim🇰🇷 · K. N. Vishnudath🇨🇱

   We study high-energy charged-lepton-flavor-violating (cLFV) channels in $e^{-}{\mu }^{+}$ scattering to probe heavy sterile neutrinos, which arise naturally in minimal extensions of the Standard Model. For $\sqrt{s}\le 2M_W$, we consider the process $e^{-}{\mu }^{+}\to e^{+}{\mu }^{-}$, which is dominated by one-loop box diagrams. We numerically evaluate these diagrams, involving a high-energy extension of the Inami-Lim functions, and find that the amplitudes are strongly suppressed because of their quartic dependence on light-heavy mixing. Using current bounds on active-sterile neutrino mixing, we determine the maximal rates allowed by existing constraints. For $\sqrt{s}>2M_W$, we analyze the process $e^{-}{\mu }^{+}\to W^{+}{W}^{-}$ and compute the corresponding cross sections in both single-sterile and minimal type-I seesaw scenarios. We find this latter process to be significantly more promising for revealing the presence of heavy sterile neutrinos at $e-\mu$ colliders.

   hep-ph2 citations
10. 10*

    Probing Signatures of Right-Handed Neutrinos via $b\to s\nu \bar{\nu }$ Decays

    Prisha🇮🇳 · Priyanka Boora🇮🇳 · Dinesh Kumar🇮🇳 · Jitendra Kumar🇮🇳

    The recent Belle II measurement of $\mathcal{B}(B^{+}\to K^{+}\nu \bar{\nu })$, which deviates from the Standard Model prediction, provides a strong motivation to search for New Physics in $b\to s\nu \bar{\nu }$ transitions. We perform a model-independent analysis within the low-energy effective theory, focusing on dimension-six vector operators involving right-handed neutrinos. Using the Belle II measurement of $\mathcal{B}(B\to K\nu \bar{\nu })$ together with the upper limit on $\mathcal{B}(B\to K^{\ast }\nu \bar{\nu })$, we constrain the new physics interactions. We study the correlation of $\mathcal{B}(B\to K\nu \bar{\nu })$ with $\mathcal{B}(B\to K^{\ast }\nu \bar{\nu })$, $\mathcal{B}(B_s\to \varphi \nu \bar{\nu })$, $\mathcal{B}({\Lambda }_b\to \Lambda \nu \bar{\nu })$, and the longitudinal polarization fraction $F_L^{K^{\ast }}$. We find sizeable enhancements in all branching fractions studied, while $F_L^{K^{\ast }}$ offers complementary sensitivity to the underlying RHN interaction structure. These results provide testable signatures of right-handed neutrino interactions at Belle~II and LHCb, and at the future FCC-ee experiment.

    hep-ph0 citations
11. 11*

    Lepton $g-2$ non-universality of hadronic contributions and a sub-GeV window to New Physics

    Siyuan Li🇩🇪 · Vladimir Pascalutsa🇩🇪 · Maxim Pospelov🇺🇸

    We propose the linear combination of the anomalous magnetic moments of the muon and electron, $a_{\mu -e}\equiv a_{\mu }-(m_{\mu }/m_e{)}^2{a}_e$, as a natural low-energy window quantity that may directly probe the current discrepancy between the data-driven and lattice-QCD evaluations of hadronic contributions. The rescaling ensures an exact cancellation of the short-range effects, thereby improving the UV behavior and bypassing a number of issues that arise in $a_{\mu }$ or $a_e$ separately. The hadronic-vacuum-polarization effect in $a_{\mu -e}^{\mathrm{HVP}}$, together with its uncertainty, is reduced as compared to $a_{\mu }^{\mathrm{HVP}}$ by $\sim 85\%$. This is promising for tests of New Physics, conditional to significant improvements in experimental measurements of $a_e$ and $\alpha$. One can foresee the improvements in tests of New Physics with some degree of flavor non-universality, as well as for the flavor-universal sub-GeV states.

    hep-phhep-thnucl-th1 citation
12. 12*

    A Low-Rank Ternary Structure of Fermion Masses and Hidden Flavor Coordinates

    Petr Baron🇨🇿

    We investigate an empirical low-rank structure underlying the fermion mass spectrum. The construction is based on an integer exponent matrix L=QG+Be, where Q labels shell type, G labels generation, and Be introduces a correction affecting only the first generation. The resulting matrix reproduces the observed hierarchy of fermion masses using a small number of integer parameters. The construction naturally introduces hidden coordinates X=(Q,G,C) associated with each fermion species. We show that fermion masses depend primarily on the projected quantity L, while flavor information appears to require the full hidden-state coordinates. Possible implications for the observed structure of the CKM and PMNS mixing matrices are briefly discussed.

    hep-ph2 citations
13. 13*

    Probing Dark Photons from Nuclear De-excitation in Reactor Neutrino Experiment

    Yuanchao Lou🇨🇳 · Lei Wu🇨🇳

    Reactor neutrino experiments serve as powerful probes of light new physics. We investigate MeV-scale visible dark photons ($A^{\prime }$) produced in nuclear reactors through nuclear de-excitation following neutron capture $N^{\ast }\to N{A}^{\prime }$. Compared with the conventional Compton-like production process $\gamma e^{-}\to A^{\prime }{e}^{-}$, the nuclear de-excitation yields on-shell dark photons with masses up to the nuclear transition energy. Using data from the TEXONO CsI(Tl) detector, we derive the new constraints on the kinetic mixing parameter $ϵ$ for dark photon masses in the range $0.1\mathrm{MeV}<m_{A^{\prime }}<6.9\mathrm{MeV}$. We find that nuclear de-excitation not only extends the mass reach of reactor searches to higher dark photon masses but also provides a stronger limit than the Compton-like production process.

    hep-ph1 citation
14. 14*

    Principles and Possibilities for Bound States in Gauge Theory

    Paul Hoyer🇫🇮

    Bound states differ from scattering yet are not covered in textbooks on Quantum Field Theory. I discuss a perturbative method for QED and QCD based on canonical quantization. Fully fixing temporal gauge $A^0(t,\mathbf{x})=0$ imposes Gauss' law on physical states. As pointed out by Dirac, this implies that electron states include a longitudinal gauge field ${\mathbf{A}}_L$, which determines the instantaneous bound state potential. The situation is analogous for quarks and gluons in QCD. An instantaneous confining potential arises for color singlet $q\bar{q}$ states when a non-vanishing boundary condition on ${\mathbf{A}}_L^a(\mathbf{x}\to \infty )$ is specified in Gauss' constraint. As suggested by Gribov, ${\alpha }_s(Q^2)$ may freeze at a perturbative value when the confining potential dominates. Hadrons can then be calculated perturbatively. At vanishing quark mass there is a $j^{PC}=0^{++}$ state with zero energy which can mix with the perturbative vacuum, giving rise to a spontaneous breaking of chiral symmetry.

    hep-phnucl-th0 citations
15. 15*

    Machine learning unveils the quark mass dependence of the pseudoscalar meson decay constants in three-flavour N${}^2$LO ChPT

    Zejian Zhuang🇪🇸 · Fernando Gil Domínguez🇨🇳 · Raquel Molina🇪🇸

    The quark mass dependence of the pseudoscalar meson decay consntants, $f_{\pi },f_K$ and $f_{\eta }$, are determined from three-flavor N${}^2$LO ChPT till pion masses around $780$ MeV, near the SU(3) limit. This is done by conducting an analysis of recent LQCD data using the LASSO method, a machine-learning technique which allows to pin down the relevant low-energy-constants with high precision. Since the pion decay constant is a fundamental quantity which usually appears in relevant phenomenological lagrangians or Effective Field Theories based on QCD at low energies, this analysis can be used as input to evaluate the quark mass dependence of hadronic states. As an example, we predict the masses of the octect baryons in the SU(3) limit within covariant Baryon Chiral Perturbation Theory.

    hep-phhep-lat0 citations
16. 16*

    Connected Sequential Bargmann Invariants and CP-Sensitive Geometric Correlation Structures in Neutral Meson Systems

    Swarup Sangiri🇮🇳

    We investigate connected sequential geometric structures in correlated neutral meson systems within the framework of Bargmann invariants. Building upon previously developed third- and fourth-order rephasing-invariant geometric structures involving decay-projected conditional states, we introduce a connected sequential fourth-order Bargmann invariant in which the decay-projected states associated with two decay channels are linked through a direct overlap between the corresponding projected states. This construction incorporates explicit projection-projection correlations within the cyclic overlap chain. The connected sequential invariant encodes the geometric relation between decay-projected states, thereby extending the geometric correlation framework developed for correlated neutral meson systems. To characterize the resulting geometric structures, we define rephasing-invariant ratios that quantify connected sequential correlations and provide a direct comparison with the previously studied disconnected geometric correlations. The behavior of these quantities is analyzed in the regime of small CP violation using the standard rephasing-invariant interference parameters together with a small-asymmetry expansion. We show that the connected sequential ratios exhibit characteristic scaling behaviors governed by both mixing asymmetry and relative interference-phase alignment, leading to geometric scaling properties distinct from those of the disconnected structures. We further discuss the geometric interpretation of the connected sequential invariants and their possible relevance to correlated neutral meson systems. The resulting framework extends the hierarchy of Bargmann invariant geometric correlations associated with neutral meson mixing and decay, providing a complementary geometric perspective on CP-sensitive interference phenomena.

    hep-ph1 citation
17. 17*

    Nuclear parton distributions and nuclear shadowing

    Petja Paakkinen🇨🇭 · Vadim Guzey🇫🇮

    In this contribution, we review the physics and phenomenology of nuclear parton distribution functions (PDFs), with a particular focus on the small-x region of nuclear shadowing. We summarise experimental evidence for nuclear modifications of PDFs and discuss their theoretical explanations; in particular, we contrast different models of nuclear shadowing. We also overview model-agnostic extractions of nuclear PDFs from global data on hard processes with nuclei, emphasizing the validity of collinear factorization and the dominance of leading-twist nuclear PDFs. Finally, we discuss perspectives for present and future precision studies of nuclear PDFs and small-x QCD dynamics, including photonuclear reactions in heavy-ion ultraperipheral collisions at the Large Hadron Collider and lepton-nucleus deep inelastic scattering at the future Electron-Ion Collider.

    hep-phnucl-th2 citations
18. 18*

    Scalar and spin-two energy-momentum-tensor structure in near-threshold charmonium probes of the proton

    Arkadiy I. Syamtomov🇺🇦

    I analyze the energy-momentum-tensor (EMT) content of the chromoelectric operator that governs the leading interaction of compact charmonium with soft gluonic fields. In the renormalized MS operator basis this interaction separates into a scalar anomaly/sigma branch and a traceless spin-two branch. The forward light-front spin-two term is fixed by partonic plus-momentum fractions and gives a controlled correction to scalar dominance. Off forward, however, the chromoelectric spin-two contraction is not governed by $A_i(t)$ alone; it also contains the combination $3B_i(t)-D_i(t)$, equivalently $6J_i(t)-3A_i(t)-D_i(t)$. This identifies which EMT structures charmonium can access in forward and differential observables, without interpreting the measured slope as a model-independent static three-dimensional mass radius.

    hep-ph1 citation
19. 19*

    Detector Resolution and Observable Infrared Memory in QED

    Takeshi Fukuyama🇯🇵

    Infrared divergences in QED cancel in inclusive observables through the Bloch--Nordsieck and KLN mechanisms. However, this cancellation removes only the unphysical infrared regulator. The detector resolution scale ${\omega }_{\max }$, which specifies the maximum energy of unresolved soft photons, remains in the observable cross section. We emphasize that this surviving scale has a natural interpretation as a coarse-graining scale in the reduced density matrix of the hard sector. Soft photons below ${\omega }_{\max }$ are not observed and are effectively traced over. The corresponding soft-sector overlap therefore becomes resolution dependent, $D_{ij}=D_{ij}({\omega }_{\max })$. Observable infrared memory is consequently defined not only by the asymptotic soft sector itself, but also by the resolution scale separating observed and unobserved infrared degrees of freedom. This provides a bridge between the traditional infrared-safe cross-section formulation and the modern interpretation of soft photons as carriers of infrared memory and quantum information.

    hep-phhep-th2 citations
20. 20*

    Semi-leptonic $B$ decays to tensor mesons

    Shao-Qin Guo🇨🇳 · Zhi-Qing Zhang🇨🇳 · Xin-Yu Cai🇨🇳 · Feng-Qing Hu🇨🇳

    Using the form factors of the transtions $B\to T$ with $T$ refering to a tensor meson, such as $a_2(1320),f_2(1270),K_2^{\ast }(1430),D_2^{\ast }(2460)$ and $D_{2s}^{\ast }(2573)$, within the covariant light-front quark model (CLFQM), we provide a detailed investigation of the corresponding semi-leptonic decays $B\to T\ell {\nu }_{\ell }$ with $\ell =e,\nu ,\tau$. All the branching ratios of these decays are larger than $10^{-5}$, in which the maximum value can reach up to $10^{-3}$, indicating promising prospects for experimental observation. Furthermore, we also calculate the longitudinal polarization fractions $f_L$ and forward-backward asymmetries $A_{FB}$ for these considered decays. All the decays $B\to T\ell {\nu }_{\ell }$ are dominated by the longitudinal polarization, where the polarization fractions can reach up to $\sim 70\%$ for the decays $B\to T{\ell }^{\prime }{\nu }_{{\ell }^{\prime }}$ with ${\ell }^{\prime }=e,\mu$, those of the decays $B\to T\tau {\nu }_{\tau }$ are a little smaller. The $A_{FB}$ values of the decays $B\to T{\ell }^{\prime }{\nu }_{{\ell }^{\prime }}$ and $B\to T\tau {\nu }_{\tau }$ have opposite signs.

    hep-ph0 citations
21. 21*

    From QCD sum rules to HQET sum rules: Heavy-quark limit of four-quark operator matrix elements

    En-Qi Wu🇨🇳 · Yi-Peng Xing🇨🇳 · Chen-Hang Weng🇨🇳 · Zhen-Xing Zhao🇨🇳

    Heavy quark expansion theory provides the standard theoretical framework for understanding the lifetimes of weakly decaying heavy-flavor hadrons. Within this framework, the matrix elements of four-quark operators play a crucial role in explaining the lifetime differences among hadrons containing the same heavy quark. In this work, we calculate these matrix elements at leading order using full QCD sum rules, with particular emphasis on deriving the corresponding HQET sum rules by taking the heavy-quark limit. While this limit is straightforward for most contributions, it turns out to be rather nontrivial for certain ones. Numerical analyses show that the results obtained from the two approaches are consistent with each other. We further clarify the origin of the large discrepancies reported in the literature between full QCD sum rule and HQET sum rule results. This work contributes to a deeper understanding of the relationship between the two sum-rule approaches and is expected to facilitate future applications of QCD and HQET sum rules in the study of heavy-flavor hadrons. The findings presented here may be of interest to both practitioners of QCD sum rules and researchers working on effective field theories.

    hep-phPRD(2026)·1 citation
22. 22*

    Role of higher twist distributions in the tomography of proton

    Navpreet Kaur🇮🇳 · Shubham Sharma🇷🇺 · Abi Jebarson A🇮🇳 · Harleen Dahiya🇮🇳

    We have studied the higher-twist distributions of the proton, including T-even and T-odd transverse momentum-dependent parton distributions (TMDs). Under the umbrella of the light-front framework, we have chosen two distinctive approaches of quark-spectator systems for comparison, one inspired by the soft-wall AdS/QCD and another with a dipolar form factor at the nucleon-quark-diquark vertex. The comprehensive picture at higher-twist provided by both T-even and T-odd TMDs not only aids deeper insights into the internal structure of the proton in the quark sector but also provides an interpretation of different components of the energy-momentum tensor in quantum chromodynamics. Hence, using these standard parton distribution functions, further predictions regarding the physical insights of gravitational TMDs in momentum space are also provided.

    hep-phPRD(2026)·0 citations
23. 23*

    Constraining DVCS Compton Form Factors Using Lattice QCD informed Neural Network

    Yuan-Yuan Huang🇨🇳 · Xu Cao🇨🇳

    The lattice QCD calculation of generalized form factors are exploited to determine the subtraction constants through all order dispersion relations of Deeply Virtual Compton Scattering (DVCS). The leading order relation is found to constrain significantly the real part of the Compton Form Factors (CFFs), and the higher order one reduces considerably both the real and imaginary part of CFFs in a global analysis of proton data. This is realized by a synthesis of the DVCS data and LQCD calculations within a neural network framework, whose architecture is specifically designed for a reliable extrapolation to unmeasured kinematic regime. By leveraging dispersion relations beyond leading order, our framework allows for adding higher moments of generalized parton distributions (GPDs) from LQCD into the extraction of CFFs from DVCS data.

    hep-phhep-lat0 citations
24. 24*

    The Muon and Tau Electric Dipole Moments in the B-L Supersymmetric Standard Model

    Wen-Hui Zhang🇨🇳 · Jin-Lei Yang🇨🇳 · Zhao-Feng Ge🇨🇳 · Yu-Li Yan🇨🇳 · Yin-Jie Zhang🇨🇳

    Recently proposed experiments are expected to significantly improve the measurement sensitivities of the electric dipole moments (EDMs) of muon ($d_{\mu }$) and tau ($d_{\tau }$). Given that theoretical predictions for $d_{\mu }$ and $d_{\tau }$ typically surpass those for the electron EDM, this work focuses on studying the contributions from the CP-violating (CPV) effects in the B-L supersymmetric (SUSY) standard model (B-LSSM) to $d_{\mu }$ and $d_{\tau }$. After considering the corrections from some two-loop diagrams, the contributions in the B-LSSM to the EDMs of charged leptons are presented analytically in general forms. The numerical results show that the traditional $\mu$-term in most SUSY models makes dominant contributions to $d_{\mu }$ and $d_{\tau }$, while the B-LSSM specific CPV parameters also induce significant effects. It is found that across a substantial region of the B-LSSM parameter space, $d_{\mu }$ falls well within the projected sensitivity at Phase II of the proposed experiment, and $|d_{\tau }|$ can reach about $10^{-21}e\cdot \text{cm}$.

    hep-ph0 citations
25. 25*

    Five-flavor $udsc\bar{b}$ molecular pentaquarks from heavy-quark and local hidden gauge symmetries

    Ratirat Suntharawirat🇹🇭 · Nongnaphat Ponkhuha🇹🇭 · Daris Samart🇹🇭

    We study a family of genuinely exotic five-flavor molecular pentaquark states containing the five quark flavors $u,d,s,c,b$ that form experimentally accessible hadrons. We construct the meson-baryon interaction from the local hidden gauge symmetry combined with heavy-quark spin symmetry, following the chiral unitary description that reproduces the LHCb hidden-charm strange pentaquarks. Heavy-quark flavor symmetry allows us to obtain the $udsc\bar{b}$ sector by replacing the anti-charm quark in the meson with an anti-bottom quark while keeping the charm quark in the baryon. As a result, we obtain ten threshold-associated isoscalar poles with $J^P=1/2^{-},3/2^{-},5/2^{-}$ in the range $7.72$ to $7.96$ GeV. They are narrow and organized into heavy-quark spin multiplets with predicted near-degeneracies. There are four states that overlap with the earlier two-sector study in the literature to about $2$ MeV, which shows that the separate-sector treatment is recovered as a limit of this work. Moreover, we also identify two additional, more deeply bound $B_s{\Lambda }_c$ and $B_s^{\ast }{\Lambda }_c$ poles generated by strong inter-channel coupling because these poles are farther from their dominated thresholds. This is an interesting signal that can be searched for at LHCb in the $B_c\Lambda$ and $B_s^{\ast }{\Lambda }_c$ invariant mass spectra.

    hep-phnucl-th1 citation
26. 26*

    Meson-Nucleus Bound States with Neural-Network Quantum States

    Wei-Lin Wu🇨🇳 · Liang-Zhen Wen🇨🇳 · Shi-Lin Zhu🇨🇳

    We present the first systematic calculations of $\varphi$-, ${\eta }_c$-, and $J/\psi$-nucleus ground states up to mass number $A=12$ based on the HAL QCD meson-nucleon potentials at near-physical point. The $(A+1)$-body Schrödinger equation is solved with a neural-network variational Monte Carlo framework, generalized to incorporate mesonic degrees of freedom. Benchmarking on light nuclei from ${}^2$H to ${}^{12}$C yields ground-state energies consistent with experiment. Meson-nucleus bound states emerge at $A\ge 2$ for $\varphi$, $A\ge 4$ for $J/\psi$, and $A\ge 6$ for ${\eta }_c$. The $\varphi$-nucleus systems exhibit the strongest binding, with binding energies reaching tens of MeV. The $J/\psi$-nucleus and ${\eta }_c$-nucleus systems are weakly bound at the few-MeV and sub-MeV scale, respectively. The binding energy per nucleon deepens nearly linearly with $A$ for charmonium systems, whereas the $\varphi$-nucleus system exhibits a non-monotonic behavior peaking at ${}^4$He -- a distinctive hallmark of the short-range and strongly attractive $\varphi N$ interaction. The meson compresses the nucleon distribution relative to the parent nucleus, and evolves from a halo configuration to one embedded inside the nucleus with increasing $A$. Our results provide predictions for future experimental searches, and establish a quantitative bridge between lattice QCD meson-nucleon interactions and the emergent many-body phenomena in meson-nucleus bound states.

    hep-phhep-exhep-latnucl-ex+12 citations
27. 27*

    Fluctuations and correlations of conserved charges in the Polyakov chiral SU(3) quark mean field model

    Dhananjay Singh🇮🇳 · Arvind Kumar🇮🇳

    We compute generalized susceptibilities of conserved charges in the Polyakov chiral SU(3) quark mean field (PCQMF) model with the fermion vacuum term. At ${\mu }_B=0$ MeV, the calculation covers the diagonal ${\chi }_n^{B,Q,S}$ through eighth order and all twelve independent fourth-order off-diagonal correlators. Extending to finite ${\mu }_B$ at ${\mu }_Q={\mu }_S=0$, we compute ${\chi }_n^B$ through eighth order, ${\chi }_n^{Q,S}$ through fourth order, the second-order off-diagonals, all twelve fourth-order off-diagonal correlators, and the odd-order baryon susceptibilities ${\chi }_1^B$, ${\chi }_3^B$, ${\chi }_5^B$. The calculation includes the vacuum term (vac=1) and is repeated for an independently refitted no-sea variant (vac=0). At ${\mu }_B=0$ MeV, the chiral pseudocritical temperature is $T_{\mathrm{pc}}=170.5$ MeV (vac=1) and $166.4$ MeV (vac=0), while the Polyakov-loop deconfinement temperature is $T_{\mathrm{dec}}=144.4$ MeV (vac=1) and $146.6$ MeV (vac=0). In vac=1, the derivative $-d{\Delta }_{l,s}/dT$ of the subtracted chiral condensate develops an inflection near $T_{\mathrm{dec}}$. Higher derivative orders resolve the chiral-deconfinement splitting as twin maxima in ${\chi }_4^B$ and ${\chi }_6^Q$, twin minima in ${\chi }_8^B$ and ${\chi }_8^Q$, and multiple zero crossings in ${\chi }_6^B$. Among the fourth-order off-diagonal correlators, vac=1 amplitudes exceed vac=0 in the BQ channel across the chiral crossover. The BS, QS, and mixed BQS components peak near the strange-melting temperature, where vac=0 dominates. Along $T_{\mathrm{pc}}({\mu }_B)$, the kurtosis ratio $R_{42}^B\equiv {\chi }_4^B/{\chi }_2^B$ of vac=1 crosses zero at ${\mu }_B/T_{\mathrm{pc}}\approx 2.15$, while vac=0 stays positive across the full range. The higher-order ratios $R_{51}^B\equiv {\chi }_5^B/{\chi }_1^B$ and $R_{62}^B\equiv {\chi }_6^B/{\chi }_2^B$ start negative in vac=1 and grow more negative as ${\mu }_B$ increases.

    hep-ph0 citations
28. 28*

    Space- and time-like electromagnetic form factors of the $\mathbf{\Omega }$ baryon

    L. Albino🇲🇽 · B. Almeida-Zamora🇪🇸 · A. Bashir🇪🇸 · J.J. Cobos-Martínez🇲🇽 · K. Raya🇪🇸 · J. Segovia🇪🇸

    We present predictions for the elastic electromagnetic form factors of the $\Omega$ baryon in both space-like and time-like regions, computed within a confining, symmetry-preserving framework based on a vector$\otimes$vector contact interaction. The calculation is performed in the rainbow-ladder truncation of QCD's Dyson-Schwinger equations, combined with a Poincaré-covariant Faddeev equation for the three-quark bound state. The $\Omega$ baryon, composed solely of strange quarks, provides a particularly clean environment in which to investigate the role of quark mass and SU(3)-flavor symmetry in shaping baryon structure. Within this approach, the electromagnetic current is constructed consistently with the Ward-Takahashi identity, yielding four independent form factors associated with the electric monopole, magnetic dipole, electric quadrupole, and magnetic octupole moments. We compute these form factors over a broad kinematic domain and analyze their behavior in both space-like and time-like regions. The resulting static electromagnetic moments and multipole form factors of the $\Omega$ baryon exhibit a visible sensitivity to the dressed-quark anomalous magnetic moment, particularly in the magnetic and higher-order multipole sectors. The time-like form factors are obtained through asymptotic analytic continuation of the corresponding space-like solutions, allowing the construction of the effective form factor and its comparison with available experimental data and recent phenomenological analyses.

    hep-phhep-exhep-latnucl-ex+10 citations
29. 29*

    Strong-field control of the $Z$-boson resonance in $e^{+}{e}^{-}$ collisions

    Fengye Chen🇨🇳 · Qingzheng Lv🇨🇳 · Libin Fu🇨🇳

    Resonant $Z$-boson production is a cornerstone of precision electroweak physics, with its vacuum line shape set by the $Z$ mass, width, and collision kinematics. We show that a strong laser field can significantly alter this picture. By treating the field nonperturbatively, we find that laser dressing of the incoming fermions alters the effective collision kinematics and opens laser-photon exchange channels, including multiphoton processes, in $e^{+}{e}^{-}$ collisions. As a result, the $Z$-resonance profile develops distinct intensity-dependent regimes, evolving from the vacuum limit to saturation at intermediate field strengths and to an approximately quadratic enhancement at higher intensities. Additionally, the polarization composition of the produced $Z$ bosons is redistributed. In particular, at high intensities the laser-induced contribution can compensate the intrinsic chiral asymmetry of the electroweak interaction, leading to nearly parity-balanced $Z$-boson production. Our results identify that strong classical fields can dynamically control electroweak resonance phenomena, opening a bridge between strong-field QED and high-energy collider physics.

    hep-phquant-ph0 citations
30. 30*

    Searching for the pseudoscalar partner of $G(3900)$ via radiative $Y(4230)$ decays

    Vitor C. Premoli🇧🇷 · Pedro Brandão🇧🇷 · Ya-Wen Pan🇨🇳 · Li-Sheng Geng🇨🇳 · Luciano M. Abreu🇧🇷

    Inspired by the $P$-wave molecular interpretation of the recently observed vector state $G(3900)$, we analyze the production of its possible pseudoscalar partner, denoted here as $G_0(3900)$, via the radiative decay $Y(4230)\to \gamma G_0(3900)$. The $G_0(3900)$ is interpreted as a $P$-wave molecular state with quantum numbers $J^{PC}=0^{-+}$, dominated by the $D{\bar{D}}^{\ast }/\bar{D}{D}^{\ast }$ components. Although not yet experimentally established, such a structure is expected to appear near the $D{\bar{D}}^{\ast }$ threshold and to exhibit characteristic production patterns. The decay is assumed to proceed through a triangle mechanism. Depending on the model parameters and the binding energy of $G_0(3900)$, the resulting branching fraction lies in the range $\mathcal{B}(Y(4230)\to \gamma G_0(3900))=3.8\times 10^{-5}-3.3\times 10^{-4}$. Our results offer a pathway to search for signatures of $G_0(3900)$ in radiative channels and also provide a test of the consistency of loop-mediated radiative decays with a molecular description of the $Y(4230)$.

    hep-ph1 citation
31. 31*

    Model of Flavors

    Jiri Hosek🇨🇿

    The BCS-motivated idea of Weinberg and Salam on dynamical EW symmetry breaking is revived: The Higgs sector of the EW gauge model of three fermion flavors (families) is replaced with the chiral gauge $SU(3{)}_f$ quantum flavor dynamics (QFD) strongly coupled at a huge scale $\Lambda$. I. With all chiral fermions in flavor triplets the anomaly freedom demands the welcome BSM extension of the SM fermion sector by one EW-sterile neutrino ${\nu }_R$ per flavor. II. The QFD distinguishes flavors by generating at strong coupling the chirality-prohibited (i.e. calculable) fermion masses: Three different Majorana masses $M_f\sim \Lambda$ of ${\nu }_R$, and three different, arguably small Dirac masses $m_f$ of SM fermions degenerate for all species in each flavor. 1. Complete spontaneous breakdown of $SU(3{)}_f\times U(1)$ by $M_f$ implies: (i) All flavor gluons acquire self-consistently masses $\sim M_f$. (ii) There is the ${\nu }_R$-composite pseudo-NG Majoron. (iii) There are three very heavy $0^{+}$ ${\nu }_R$-composite Higgs bosons. 2. Spontaneous breakdown of the EW $SU(2{)}_L\times U(1{)}_Y$ symmetry to $U(1{)}_{em}$ by $m_f$, in sharp contrast with the Higgs mechanism, implies: (i) The $W$ and $Z$ bosons acquire masses $\sim g(\sum m_f^2{)}^{1/2}$ and $\sim (g^2+g^{{}^{\prime }2}{)}^{1/2}(\sum m_f^2{)}^{1/2}$ respectively, defining the effective Fermi scale $v=246\mathrm{GeV}$. (ii) There are three SM-fermion-composite $0^{+}$ Higgs bosons $h_f$ at this scale. III. The UV-finite EW dynamical perturbation theory of Pagels and Stokar splits the flavor-degenerate masses of SM-fermions by their electric charges and the ratios $m_f/m_{W,Z}$. Six Majorana neutrino masses are calculable by seasaw.

    hep-phhep-th0 citations
32. 32*

    "Hadron-in-fat-jet'' AI Tagging to Detect Rare Decays Such as $W^{\pm }\to {\pi }^{\pm }\gamma$

    Linrui Chen🇨🇳 · Tianyi Yang🇨🇳 · Zixun Kou🇨🇳 · Zijian Wang🇨🇳 · Youpeng Wu🇨🇳 · Leyun Gao🇨🇳 · Qiang Li🇨🇳

    We investigate a novel class of boosted-object signatures at the LHC, where a high-$p_{\text{T}}$ fat-jet contains an identifiable hadron or quarkonium state originating from rare or semi-exclusive decays. Unlike conventional boosted jet studies, which focus on multi-prong partonic substructure, our approach probes hybrid configurations such as $W^{\pm }\to {\pi }^{\pm }\gamma$, where a localized hadronic or quarkonium signal is embedded within a collimated jet. By fine-tuning the signature-oriented, pre-trained Sophon AI model optimized for large-radius jets, and combining it with an event-level BDT and a soft-drop-mass shape fit, we obtain an expected 95\% CL upper limit of $\mathcal{B}(W^{\pm }\to {\pi }^{\pm }\gamma )<2.78\times 10^{-5}$ for $450{\mathrm{fb}}^{-1}$ in our nominal setup. This study serves as a first proof-of-principle demonstration of the ``hadron-in-fat-jet'' paradigm; substantial gains in sensitivity are expected from improved trigger strategies, additional production channels, and dedicated taggers, while the methodology itself is broadly applicable to a wide range of rare Standard Model processes and searches for light or exotic resonances at present and future collider experiments.

    hep-phhep-ex0 citations
33. 33*

    Primordial Black Holes from Slow Phase Transitions with Delayed Reheating: A Peak-Theory Approach

    Indra Kumar Banerjee🇮🇳

    We study the possibility of significant PBH production from a slow first-order phase transition with delayed reheating. Since delayed reheating results in an early matter-dominated phase between percolation and reheating, we developed a peak-theoretic approach to PBH formation during this phase based on the non-Gaussian distribution of overdensity arising from the transition. To obtain the collapse probability, we performed large-scale Monte Carlo simulations and employed the hoop-conjecture criterion. We include tidal-torque terms to investigate the initial spin of the PBHs and find that the average spin parameter is $\mathcal{O}(10^{-3})$. Furthermore, we obtain an emergent overdensity threshold for collapse that depends on the phase transition properties and reheating efficiency. We find that the resulting PBH abundance is extremely sensitive to the reheating efficiency, with order-unity changes in efficiency leading to variations of many orders of magnitude in the collapse fraction. We identify regions of parameter space where the resulting PBHs can account for the entirety of the dark matter abundance. Finally, we also constrain the phase transition and reheating properties from current data on (non-)observations of PBHs.

    hep-phastro-ph.COgr-qc1 citation
34. 34*

    NNLO QCD predictions for $t\bar{t}W$ production at hadron colliders

    Matteo Becchetti🇮🇹 · Dhimiter Canko🇮🇹 · Xiang Chen🇨🇭 · Vsevolod Chestnov🇬🇧 · Maximilian Delto🇨🇭 · Sara Ditsch🇩🇪 · Massimiliano Grazzini🇨🇭 · Stefan Kallweit🇨🇭 · Tiziano Peraro🇮🇹 · Mattia Pozzoli🇮🇹 · Chiara Savoini🇩🇪 · Lorenzo Tancredi🇩🇪 · Simone Zoia🇨🇭

    The production of a top-antitop quark pair in association with a $W$ boson constitutes one of the heaviest final states currently studied at the Large Hadron Collider (LHC) at CERN. Measurements of its production rate have consistently exceeded Standard Model predictions. Owing to the complexity of the two-loop amplitudes entering the double-virtual correction, next-to-next-to-leading-order (NNLO) QCD calculations for this process have so far employed dynamical approximations for the two-loop contribution. We present NNLO QCD predictions based, for the first time, on a direct computation of the required two-loop amplitudes in the generalised leading-colour limit.

    hep-ph4 citations
35. 35*

    Lifting Effective-Field-Theory Degeneracies in Semileptonic Heavy-Baryon Decays

    Hindi Zouhair🇲🇦

    Semileptonic heavy-baryon decays provide a sensitive probe of the helicity structure underlying possible lepton-flavor universality violation in $b\to c\tau {\bar{\nu }}_{\tau }$ transitions. We perform an effective-field-theory analysis of ${\Lambda }_b\to {\Lambda }_c\tau {\bar{\nu }}_{\tau }$ and related baryonic modes using lattice-QCD helicity form factors with full covariance propagation. Propagating meson-compatible EFT solutions into the baryonic observable space$(R_{{\Lambda }_c},P_{\tau },A_{\mathrm{FB}})$, we show that tau polarization provides the leading source of sensitivity for lifting EFT degeneracies that remain unresolved in current measurements of $R(D)$ and $R(D^{\ast })$. Vector-like and tensor-like solutions remain clustered near theStandard-Model prediction, whereas scalar-containing directions produce large polarization displacements and characteristic low-$q^2$ deformations of the normalized differential spectrum. A covariance-aware analysis demonstrates that baryonic polarization and differential observables provide complementary and independent information on the Lorentz structure of semileptonic new physics. $P_{\tau }({\Lambda }_b\to {\Lambda }_c\tau {\bar{\nu }}_{\tau })$ and the low-$q^2$ spectrum as particularly powerful probes for future tests of semitauonic flavor anomalies at LHCb and future flavor facilities.

    hep-ph0 citations
36. 36*

    Effective QCD model with consistent quasi-gluon treatment : formulation and application

    Chowdhury Aminul Islam🇩🇪 · Munshi G. Mustafa🇮🇳 · Rajarshi Ray · Pracheta Singha🇷🇴

    The Polyakov loop enhanced Nambu-Jona-Lasinio model is reformulated in terms of the gluon quasi-particles in addition to the already existing quark quasi-particles. The formulation goes beyond the saddle point approximation for the gluon sector. The framework provides a physically consistent quasiparticle model for QCD thermodynamics. The ensuing advantages of this formulation is discussed using transport coefficients in the light quark sector.

    hep-phnucl-th0 citations
37. 37*

    PTA-Compatible Domain Walls at LISA and Taiji: Bayesian Reconstruction and Multiband Inference

    Satyabrata Datta🇨🇳 · Rome Samanta🇮🇹

    Domain walls provide an excellent fit to Pulsar Timing Array (PTA) data. A distinctive feature of the associated gravitational-wave (GW) spectrum is its ultraviolet (UV) tail, which can extend into the mHz band and thereby make cross-detection with space-based interferometers such as LISA and Taiji possible. In this work, we explore the PTA-compatible parameter space of domain-wall models and study both the reconstruction prospects at LISA and Taiji and the information gain achievable through joint PTA--LISA and PTA--Taiji analyses. We find that LISA and Taiji can probe an extended region of parameter space yielding an ultraviolet tail in the milli-Hz band, even in the presence of astrophysical foregrounds. Within the PTA-supported region, however, the genuinely informative regime is more restricted and concentrated toward the high-signal edge. In the space-based-detector-only analysis, the posterior is strongly degenerate in the underlying model parameters, although one principal parameter combination can be reconstructed with high precision where the signal is sufficiently strong. When PTA-informed priors are incorporated, the additional information gain is localized to the same high-signal region: there the space-based data produce a non-negligible posterior update and strongly suppress the catastrophic LISA(Taiji)-only degeneracy, while the final posterior often retains an axis ratio comparable to that of PTA alone. Our analysis is based on a 10-dimensional Bayesian inference with two domain-wall signal parameters and eight nuisance parameters describing instrumental noise and astrophysical foregrounds. We use 49 grid injections for the LISA-only and Taiji-only analyses and 65 injections from the PTA-supported region for the joint analyses, with Clough--Tocher interpolation used to construct posterior heat maps.

    hep-phastro-ph.COastro-ph.IMgr-qc4 citations
38. 38*

    Finite Massless Pentaboxes

    Gustavo Figueiredo🇫🇷 · David A. Kosower🇫🇷 · Pavel P. Novichkov🇧🇪

    We characterize the integrand numerators that give rise to locally finite or evanescent Feynman integrals for the massless pentabox. We provide compact expressions for the generators of the corresponding ideal in terms of an adapted momentum basis and also in terms of Gram determinants. We also compute the integrals corresponding to the lowest-rank numerators in terms of polylogarithms using the HyperInt package, and in terms of pentagon functions.

    hep-phhep-th2 citations
39. 39*

    Finite-$t$ and target mass corrections for the short-distance expansion of quasi(pseudo) GPDs

    Vladimir M. Braun🇩🇪 · Hua-Yu Jiang🇨🇳

    We calculate the ``kinematic'' corrections $t/P_z^2$ and $m_N^2/P_z^2$ to the short distance expansion of gauge-invariant nonlocal quark-antiquark operators sandwiched between nucleon states with different momenta. Here $t$ is the momentum transfer, $m_N$ is the nucleon mass and $P_z$ is the momentum component in the direction of the quark-antiquark separation, which is assumed to be large. These matrix elements can be calculated in lattice QCD and, at leading twist, expressed in terms of moments of the generalized parton distrubutions (GPDs). Our results allow one to control one of principal uncertainties in such calculations and extend their region of applicability to larger momentum transfers, which is important in the quest to access the three-dimension image of the proton. The calculated corrections turn out to be significant for a realistic lattice QCD setup.

    hep-ph0 citations
40. 40*

    Partial Pressure Contributions of Hadron Families to the QCD Equation of State

    Jonathan Gonzales🇺🇸 · Alejandro Florez🇨🇴 · Johannes Jahan🇺🇸 · Angel R. Nava Acuna🇺🇸 · Naman Mehndiratta🇺🇸 · Claudia Ratti🇺🇸

    Lattice simulations provide the thermodynamics of quantum chromodynamics (QCD) as a function of the temperature, at zero-to-moderate values of the baryonic chemical potential. However, the contribution of single hadronic species cannot be directly isolated from lattice calculations. In this work, we find linear combinations of up to fourth order susceptibilities which isolate the contribution of hadrons to the QCD pressure according to their baryon number $B$, electric charge $Q$ and strangeness $S$ content. These combinations are valid, provided that the thermodynamics of a strongly-interacting gas in the low-temperature regime can be modeled as a gas of non-interacting hadrons and their resonances. Finally, we test the validity of these linear combinations in the Hadron Resonance Gas (HRG) model and compare them to available lattice QCD results, using continuum-estimated susceptibilities.

    hep-phhep-latnucl-th2 citations
41. 41*

    Einstein-de Haas effect and induced rotation in an evolving magnetized QCD matter

    Dushmanta Sahu🇲🇽 · Captain R. Singh🇮🇳

    The Einstein-de Haas (EdH) effect describes the emergence of collective rotation driven by spin alignment under an external magnetic field. We investigate this effect in a dynamically expanding quark-gluon plasma (QGP) using a quasiparticle model (QPM). We compute the EdH-induced angular velocity ${\omega }_{\mathrm{EdH}}$ as a function of temperature, proper time, and fireball radius. Our results show that ${\omega }_{\mathrm{EdH}}$ grows with proper time and is consequently suppressed at higher temperatures. Near the QGP crossover temperature, ${\omega }_{\mathrm{EdH}}$ attains a substantial, non-negligible magnitude. We identify a nontrivial crossing between the strong and weak magnetic field regimes that reflects the competition between spin alignment and the energy required to sustain orbital motion. This nontrivial crossing temperature separates a spin-dominated regime from an inertia-dominated regime of magnetic field-induced rotation. These findings establish the EdH effect as a manifestation of angular momentum conservation in magnetized QCD matter.

    hep-phhep-thnucl-th1 citation
42. 42*

    Dispersive analysis of the $\mathbf{J}/\mathbf{\psi }\to \mathbf{\gamma }{\mathbf{\pi }}^0{\mathbf{\pi }}^0$ process

    Bai-Long Hoid🇩🇪 · Igor Danilkin🇩🇪 · Anna Testa🇩🇪 · Marc Vanderhaeghen🇩🇪

    We present a dispersive amplitude analysis of the low-energy ${\pi }^0{\pi }^0$ system in the radiative decay $J/\psi \to \gamma {\pi }^0{\pi }^0$, using the mass-independent BESIII $0^{++}$ and $2^{++}$ intensities, the total spectrum, and the measured $0^{++}-2^{++}$ $E1$ phase difference. The isoscalar $S$-wave is described by a coupled-channel $\pi \pi /K\bar{K}$ Muskhelishvili-Omnès representation, which implements the strong final-state interactions associated with the $f_0(500)$ and $f_0(980)$. The $D$-wave is treated with a single-channel $\pi \pi$ Muskhelishvili-Omnès representation, where we identify all kinematic constraints of helicity amplitudes before transforming them to the experimental $E1$, $M2$, and $E3$ multipoles. Smooth short-distance production of a pseudoscalar-meson pair is encoded in subtraction polynomials, while left-hand-cut effects are estimated and found to be numerically subleading. We identify the negative solution of the BESIII $0^{++}-2^{++}$ $E1$ phase ambiguity, after using the modulo-$\pi$ freedom of production amplitudes, as the phase solution compatible with unitarity constraints, showing that the measured phase information can be accommodated with the Omnès phase motion without requiring large additional phases. By normalizing the BESIII intensities with the extracted branching fraction, we fix the absolute scale of the fitted amplitudes, making them suitable as input for future dispersive studies of two-pion contributions to gravitational form factors.

    hep-phhep-exhep-latnucl-th1 citation
43. 43*

    Higher-dimensional operators and Polyakov loop in hot Scalar QED from the heat kernel

    Siddhartha Bandyopadhyay🇮🇳 · Joydeep Chakrabortty🇮🇳 · Debmalya Dey🇮🇳 · Philipp Schicho🇨🇭 · Tushar🇮🇳

    Using the finite-temperature heat kernel method, we compute the gauge-invariant effective Lagrangian up to dimension-six for massive hot scalar QED. We propose two complementary methods: integrating out heavy modes at finite temperature, and deriving the finite-temperature heat kernel coefficients from the zero-temperature ones. We show that in the static limit, both lead to the same three-dimensional effective operators. We also compute the gauge-invariant Coleman-Weinberg effective potential for a constant background at finite temperature. We further examine how the Polyakov loop modifies the matching coefficients and assess its impact together with the higher-dimensional operators on the thermodynamics of cosmological first-order phase transitions, which in turn can affect an associated gravitational-wave spectrum.

    hep-phgr-qchep-th4 citations
44. 44*

    Testing Supersymmetric Hidden Sectors with Long-Baseline Atom Interferometers

    Oem Trivedi🇺🇸

    Atomic interferometry provides a sensitive near Earth probe of high energy physics through precision measurements of quantum phase. In this Letter, we point out that MAGIS and AION like long-baseline atom interferometers can also be used to test supersymmetric hidden sectors, if these sectors contain ultralight moduli, dilatons or hidden scalars that induce coherent phase oscillations. In such a setup, the measured atomic phase does not only constrain an effective phenomenological scalar coupling. It can be related to derivatives of supersymmetric gauge kinetic functions, Kähler metrics, Yukawa couplings, Higgs sector parameters and the QCD scale along light hidden sector directions. We derive the mapping from a generic SUSY/SUGRA modulus to the effective atom interferometric coupling, and show that future phase sensitivities may probe very small visible sector admixtures of otherwise hidden fields. This identifies MAGIS/AION type experiments as non-collider probes of supersymmetric and string-motivated infrared relics, complementary to gravitational wave, astrophysical and collider searches.

    hep-phgr-qchep-th0 citations
45. 45*

    Radio Emission from High-Frequency Gravitational Wave Point Sources

    Ethan Baker🇺🇸 · Hongwan Liu🇺🇸

    High-frequency gravitational waves (HFGWs) in the MHz to GHz regime can convert into radio photons in the presence of astrophysical magnetic fields through the inverse Gertsenshtein effect. We show that existing radio telescopes like CHIME and FAST are excellent tools for detecting HFGW sources, significantly outperforming many existing experiments at detecting primordial black hole (PBH) mergers, the most realistic sources of transient HFGWs. Radio telescopes are also uniquely sensitive to sources of monochromatic HFGW emission, such as ultralight boson clouds formed through superradiance around PBHs, and are likely to have excellent sensitivity to generic sources of detectable HFGWs.

    hep-phastro-ph.COastro-ph.HEgr-qc2 citations
46. 46*

    Too Heavy to Hide: Gamma-Ray Constraints on Annihilating Dark Matter beyond Unitarity

    Abhishek Dubey🇮🇳 · Deep Jyoti Das🇮🇳 · Akash Kumar Saha🇮🇳

    The measurement of high energy diffuse gamma rays by various ground-based air shower detectors have opened a new chapter for high energy particle physics and astrophysics. The broad range of viable dark matter candidates motivates extending indirect searches to heavier dark matter masses, opening new opportunities to uncover the nature of dark matter. If dark matter is composite rather than point-like, then the thermal unitarity bound can be relaxed, opening up the possibility of dark matter masses far beyond the electroweak scale. We perform a model agnostic search for heavy annihilating dark matter using the gamma-ray measurements and upper limits from Tibet AS${}_{\gamma }$, LHAASO, KASCADE-Grande, Pierre Auger Observatory, and Telescope Array. These highest energy datasets enable us to probe new regions of parameter space and set world-leading limits on the annihilation cross sections for dark matter masses $10^5$--$10^{12}$ GeV. Our work highlights the power of high energy gamma-ray datasets in discovering heavy dark matter signatures in the near future.

    hep-phastro-ph.CO1 citation
47. 47*

    Probing lepton number violation at FCC-ee

    Praveen Bharadwaj🇮🇳 · Sanjoy Mandal🇰🇷 · Rojalin Padhan🇰🇷 · José W. F. Valle🇪🇸

    We propose high-multiplicity final-state signatures, such as $e^{+}{e}^{-}\to N\overline{N}\to {\ell }^{+}{\ell }^{+}4j$ with $\ell$ denoting $e,\mu$, $\tau$, as probes of lepton number violation (LNV) at FCC-ee, featuring negligible Standard Model background. In contrast to conventional searches such as $pp\to {\ell }^{+}N\to {\ell }^{+}{\ell }^{+}jj$ or the process $e^{+}{e}^{-}\to \nu N$, which are suppressed by the small neutrino masses in conventional seesaw scenarios, the minimal linear seesaw picture avoids this suppression. This enables a direct LNV probe from final-state topology, with over $\mathcal{O}(10^3)$ events expected at FCC-ee. Besides probing the Majorana nature of neutrinos, this offers a novel avenue to test the neutrino mass ordering established by oscillation experiments in a high-energy collider setting.

    hep-ph0 citations
48. 48*

    Constraints and Projections for Millicharged Dark Matter in the Sun with Water Cherenkov Neutrino Detectors

    Thong T.Q. Nguyen🇸🇪

    Millicharged particles are well-motivated dark matter candidates that have been extensively investigated in terrestrial experiments. Recent studies proposed using the IceCube Neutrino Observatory to search for high-energy neutrinos produced by the capture and annihilation of millicharged dark matter in the Sun, deriving new constraints in the strong interaction regime where the millicharge is $q_{\chi }\sim 10^{-3}$-$10^{-2}$, which extend to small fractional abundances where all existing constraints lose sensitivity. In this work, I point out that the lower energy threshold of water Cherenkov detectors makes Super-Kamiokande and the future Hyper-Kamiokande sensitive to neutrinos from the annihilation of lighter millicharged dark matter, complementing the high-mass reach of IceCube. I find that Super-Kamiokande can constrain previously unexplored parameter space at $m_{\chi }=5$-28 GeV for dark matter fraction of $f_{\chi }=10^{-4.5}$, while Hyper-Kamiokande can improve these constraints and will be sensitive to fractional abundances as small as $f_{\chi }\simeq 5\times 10^{-6}$, nearly an order of magnitude below current IceCube limits.

    hep-phastro-ph.HE3 citations
49. 49*

    Clustering in hadrons and light nuclei from Lorentz boosted form factors

    F.E. Rodríguez Barrera🇨🇴 · N. G. Kelkar🇨🇴

    The determination of nuclear charge radii is crucial for understanding the internal structure of nuclei and their fundamental interactions. A persistent discrepancy, not only in the measured proton charge radius but also in the light nucleus charge radius, between electron scattering and muonic spectroscopy has fueled ongoing debates in nuclear and particle physics. Using this discrepancy, we revisit the role of one of the proposed solutions, namely the use of Lorentz-boosted nuclear form factors to find a subtle connection between the boost and the cluster structure of nuclei. By applying two distinct relativistic formalisms, namely the Licht-Pagnamenta and Mitra-Kumari approaches, we systematically analyze corrections to the moments of the density distributions in hadrons and nuclei. Our results demonstrate that boosting the form factors from the Breit to the rest frame of the nucleus not only assists in reconciling the spectroscopic and scattering measurements but also provides a method to infer on the quark and nucleon cluster configurations within nuclei.

    ↳ nucl-thhep-phNPA(2026)·0 citations
50. 50*

    Weyl conformal geometry vs Riemannian geometry of Weyl gauge invariant (dressed) metric

    D. M. Ghilencea🇷🇴 · V.-M. Mandric🇷🇴

    Weyl conformal geometry is the natural underlying geometry of gauge theories of Weyl group (of dilatations and Poincaré symmetry), such as Weyl quadratic gravity and its generalisation, Weyl-Dirac-Born-Infeld action (WDBI). These are local, Weyl-anomaly free (quantum) gauge theories of gravity. We describe Weyl gauge symmetry from a more familiar Riemannian view of Weyl gauge invariant dressed fields by the Wilson line of dilatations. Weyl geometry can then be seen as Riemannian geometry of non-local dressed metric ($g_{\mu \nu }^{\ast }$), at the "cost" of (gauge-induced) non-commutativity in the UV, due to Wilson line. Then Weyl quadratic gravity and WDBI actions of Weyl geometry, which are Weyl gauge invariant in $d$ dimensions, have the same expression in Riemannian geometry defined by $g_{\mu \nu }^{\ast }$. This is a non-local map and dual description of the two geometries and actions in the symmetric phase. Unlike for the metric, the equation of motion of Weyl gauge field (${\omega }_{\mu }$) does not commute with the dressing of the metric. Quantum non-locality, in particular entanglement, and non-commutativity are (gauge-invariant) physical artefacts of "translating" (local) Weyl geometry and Weyl gauge covariance into our real-world Riemannian geometry of Weyl gauge invariant observables, and they are evidence of Weyl gauge symmetry. At lower energies, ${\omega }_{\mu }$ becomes massive, can decouple and Einstein-Hilbert action and commutativity are recovered. The case of a light ${\omega }_{\mu }$ is also discussed.

    ↳ hep-thgr-qchep-phmath-ph+13 citations
51. 51*

    Resonance Femtoscopy Beyond the On-Shell Approximation

    Liang Zhang🇨🇳 · Tianhao Shao🇨🇳 · Song Zhang🇨🇳 · Kai-Jia Sun🇨🇳 · Yu-Gang Ma🇨🇳

    The observed shift of the $\Delta (1232)$ resonance peak in $\pi$-$p$ femtoscopic correlations challenges the conventional Breit-Wigner description of resonances in femtoscopy. We revisit the Koonin-Pratt framework by formulating femtoscopy in the momentum-space representation. By employing the T-matrix approach to disentangle on-shell and off-shell contributions, we show that the finite spatial extent of the emission source naturally induces sensitivity to off-shell scattering dynamics. Using a Friedrichs-Lee model constrained by low-energy $\pi$-$p$ scattering data, we numerically demonstrate that this off-shell sensitivity leads to a peak shift accompanied by a dip on the high-momentum side of the peak. The predicted high-momentum side dip is absent in the data, pointing to source properties beyond the simple Gaussian approximation.

    ↳ nucl-thhep-ph2 citations
52. 52*

    Self-Gravitating Magnetic Monopoles and Dyons in String-Inspired Models: Structure and Stability

    Nick E. Mavromatos🇬🇷 · Sarben Sarkar🇬🇧 · Dionysios P. Theodosopoulos🇺🇸

    We present classical magnetic--monopole (MM) and dyon solutions induced by global monopoles in string-inspired gravitational models. Although several ingredients of the construction have appeared previously, we examine a new synthesis via their organised use in a self-gravitating finite-energy monopole/dyon system with explicit mass, charge, core and stability diagnostics. The global monopole provides the topological seed, while the dilaton, Kalb--Ramond (KR) axion and Born--Infeld (BI) electromagnetic (EM) sector supply the string-inspired dressing. Two related branches are analysed: (i) a dilaton--BI magnetic branch, distinct from earlier constructions, and (ii) a dyonic extension in which the KR axion couples electric and magnetic sectors through an axion-Pontryagin-anomaly interaction. In both cases BI dynamics regularises the EM self-energy within a self-gravitating global-monopole construction, and the solutions possess a de Sitter core, a positive ADM-mass parameter range and satisfy the standard energy conditions. A further novel feature is a limiting branch in which the ADM mass tends to zero while the magnetic charge remains finite, the configuration being supported by magnetic charge and de Sitter core pressure.We also examine stability diagnostics. The stress--energy tensor gives finite force components and an outward-pointing radial force, indicating absence of core collapse within the mechanical stability criterion. In the exterior analytic region we analyse gauge-invariant EM perturbations using the Gervalle-Volkov framework. The helicity modes ${\psi }_{\pm }$ obey a self-adjoint Sturm--Liouville system. MM helicities decouple, while dyons exhibit axion-induced helicity mixing and birefringent polarisation structure. Positivity of the EM helicity block provides a necessary long-range stability diagnostic; the full coupled Einstein-matter spectral problem is discussed

    ↳ hep-thhep-ph0 citations
53. 53*

    Relativistic Effects in Spin Correlations Induced by QED Scattering and Wigner Rotations

    Juan D. Fonseca🇧🇷 · B. Hiller🇵🇹 · I. G. da Paz🇧🇷 · M. Sampaio🇧🇷

    We study the relativistic nature of the interactions that, at tree level, generate spin correlations between two electrons in Møller scattering, as well as in an extended process involving a witness particle $C$. The corresponding processes, $e^{-}{e}^{-}\to e^{-}{e}^{-}$ and $e^{-}{e}^{-}C\to e^{-}{e}^{-}C$, are analyzed both in the center-of-mass frame and, for the former process, in a Lorentz-boosted frame where Wigner rotations arise. It is found that, through a nonrelativistic approximation of the scattering amplitudes, dipole-dipole and current-dipole interactions are responsible for the emergence of these correlations. This is evidenced by the variation of the von Neumann entropy of one electron for initially separable states, and of $C$ for an initially prepared three-particle entangled W-state. In Wigner rotations, the invariance of entropy under local unitary transformations is maintained at the expense of the emergence of quantum coherence in the density matrix at large rapidities. As a consequence, the final states of both particles are evaluated and shown to encode information about the scattering process through their spin expectation values. This framework is then used to comment on the correlations in the inelastic process $e^{-}{e}^{+}\to {\mu }^{-}{\mu }^{+}$, for which some research has reported differing results.

    ↳ quant-phhep-phhep-th0 citations
54. 54*

    Global Ab initio Neutrino Mass Limits from Neutrinoless Double-Beta Decay

    T. Shickele🇨🇦 · L. Jokiniemi🇨🇦 · A. Belley🇨🇦 · J. D. Holt🇨🇦

    We present global limits for Majorana neutrino masses by combining latest results from neutrinoless double-beta ($0\nu \beta \beta$) decay searches and ab initio nuclear theory. Limits are derived in a Bayesian framework utilizing likelihood functions from a suite of $0\nu \beta \beta$-decay experiments in conjunction with nuclear matrix elements calculated from nuclear and electroweak forces derived from chiral effective field theory and implemented in the in-medium similarity renormalization group many-body approach. In contrast to nuclear models, ab initio results indicate that the current generation of $0\nu \beta \beta$-decay experiments have likely \textit{not} yet reached sensitivities required to probe the mass regime allowed by neutrino-oscillation data, where the combined bounds are notably stronger than those given by individual experiments. Finally, from predicted sensitivities of next-generation searches, we show that, while no one individual experiment fully covers the inverted mass ordering, this can be achieved from combined contributions from the four key isotopes: ${}^{76}$Ge, ${}^{100}$Mo, ${}^{130}$Te, and ${}^{136}$Xe.

    ↳ nucl-thhep-exhep-phPRD(2026)·2 citations
55. 55*

    Spectral distortion anisotropies from photon to dark photon conversions

    Sara Evangelista🇬🇧 · Jens Chluba🇬🇧 · Bryce Cyr🇺🇸

    Dark photons are a gauge boson of a hypothetical dark sector, representing one of the most-studied minimal extensions of the Standard Model, with wide-ranging theoretical and observational implications. Here, we consider scenarios in which an initially unpopulated dark photon sector is populated via resonant photon to dark photon conversions. This process leads to observable spectral distortions in the cosmic microwave background (CMB), that can be used to constrain these models. We extend previous spectral distortion studies of the monopole spectrum to anisotropic spectral distortions, using the newly developed Frequency Hierarchy (FH) framework of CosmoTherm. We illustrate the physics by presenting detailed computations of the photon transfer functions and distortion cross power spectra throughout the dark photon parameter space. We find that the dark photon mass explicitly controls the shape (i.e., multipole-dependence) of the signal power spectra, while the overall amplitude of the signal is determined by the kinetic mixing parameter of the model. Using these results, we place complementary limits on the minimal dark photon model using data from Planck, finding that the constraints are only marginally weaker than those obtained with COBE/FIRAS data for the average (monopole) distortion. In addition, we compute the corrections to the standard temperature field, arguing that conversions at redshifts larger than $2\times 10^6$ may add iso-curvature type perturbations, which could lead to novel constraints in regimes where distortion anisotropies thermalize.

    ↳ astro-ph.COgr-qchep-ph1 citation
56. 56*

    Effective scalaron--photon interaction in $f(R)$ gravity

    Yuri Shtanov🇺🇦

    We revisit the effective coupling of the scalaron to gauge fields in $f(R)$ gravity minimally coupled to the Standard Model, focusing on the scalaron decay into two photons. Treating the scalaron as an intrinsic component of the Jordan-frame metric, we analyse quantum effects arising from its coupling to the energy--momentum tensor. In this framework, the trace anomaly contributes to the scalaron--gauge boson interaction. Using Fujikawa's approach, we obtain the trace-anomaly contribution, associated with the transformation of matter fields between the Jordan and Einstein frames, first in QED and then in the full Standard Model. The resulting effective scalaron--photon interaction agrees with direct perturbative calculations that include the trace anomaly and differs from the result obtained when only the classical expression for the trace of the energy--momentum tensor is taken into account in the scalaron interaction. In the limit where the scalaron mass is much smaller than the masses of particles circulating in the loop, the diagrammatic contribution from the classical expression of the trace of the energy--momentum tensor cancels the anomaly-induced term, leading to a vanishing effective coupling and a strong suppression of the scalaron decay rate into photons. These results clarify the origin of discrepancies in the literature concerning the effective scalaron coupling to massless gauge fields. They stem from inequivalent prescriptions for incorporating quantum loop effects in $f(R)$ gravity, leading to different scalaron--gauge field interactions with direct implications for scalaron dark-matter phenomenology.

    ↳ hep-thgr-qchep-phJHEP(2026)·0 citations
57. 57*

    Pantheon+ supernovae corrected for progenitor age indicate the universe is decelerating

    Animesh Sah (TIFR Mumbai) · Mohamed Rameez (TIFR Mumbai)🇮🇳 · Subir Sarkar (University of Oxford)🇬🇧

    We examine the impact of progenitor age-dependent luminosity evolution of Type Ia supernovae on a cosmographic measurement of the deceleration parameter $q_0$. Our recent redshift tomographic analysis showed that locally $q_0$ has a strong dipole anisotropy aligned approximately with the bulk flow, and only a small monopole component remains at distances exceeding a few hundred Mpc. Applying redshift-dependent corrections for progenitor age to the Pantheon+ catalogue, we find that this shifts the monopole component of $q_0$ to positive values (i.e. deceleration), while leaving the local dipole component essentially unchanged.

    ↳ astro-ph.COgr-qchep-phMNRAS(2026)·2 citations
58. 58*

    Atmospheric Neutrino Oscillations: the Full Picture

    Philipp Eller🇩🇪

    We present the first combined oscillation analysis of multiple atmospheric neutrino datasets, featuring data from Super-Kamiokande, IceCube-DeepCore, and KM3NeT/ORCA together with reactor data from Daya Bay. Such combinations have long been considered infeasible outside experimental collaborations; we demonstrate that a unified physics model can simultaneously describe all datasets with no significant parameter tensions. Fitting 839048 events across 1536 bins with 91 parameters, our combined analysis yields competitive measurements of the neutrino mixing parameters, and prefers the Normal over the Inverted Mass Ordering.

    ↳ hep-exhep-ph1 citation
59. 59*

    Universal Suppression of Gravitational Waves from Black Hole Evaporation Dynamics

    Xin-Chen He🇨🇳 · Xiao-Han Ma🇨🇳 · Misao Sasaki🇯🇵 · Volodymyr Takhistov🇯🇵

    Evaporating black holes can leave distinct imprints on gravitational wave (GW) backgrounds. We show that black hole populations with finite width mass distributions exhibit a universal late time evolution governed by the evaporation dynamics rather than the details of the initial mass distribution, leading to a characteristic power law suppression of the induced GWs. We demonstrate this for a broad class of mass functions in primordial black hole (PBH) scenarios featuring an early Universe matter-dominated era, and identify the suppression of PBH-induced GWs found for critical collapse distributions as a manifestation of this general phenomenon. Our results establish a direct connection between the asymptotic GW spectrum and the underlying law of black hole evaporation.

    ↳ astro-ph.COgr-qchep-ph1 citation
60. 60*

    Geometric Matching of Local Static Regions in Cosmological Spacetimes with an Evolving Lapse

    Seokcheon Lee

    The generalized cosmological time (GCT) framework introduces a modified lapse function, N(t)\propto a^{b/4}, as a geometric extension of the standard FLRW description. Like other departures from $\Lambda$CDM, such constructions must remain compatible with the observed stability of local gravitational and laboratory physics. In scalar--tensor theories, this compatibility is usually achieved through dynamical screening mechanisms that suppress additional degrees of freedom in dense environments. In this work, we examine whether a locally static spacetime region can be consistently embedded within a cosmological background described by a time-dependent lapse. By embedding a static Schwarzschild interior into an expanding GCT--FLRW exterior, the Israel junction conditions are used to determine the class of background expansions that admit such a matching in the absence of a thin shell. The continuity of the extrinsic curvature yields a Friedmann-type relation that coincides with the GCT background equations of motion. This relation should be interpreted not as a new dynamical equation, but as a geometric consistency condition (GCC) associated with the matching of the two spacetime regions. In this sense, the junction does not introduce new dynamics, but provides a GCC under which a region with fixed local clocks can be embedded in a cosmological spacetime with an evolving lapse. Therefore, the analysis clarifies how locally static gravitational systems can remain compatible with a cosmological time normalization that differs from that of local proper time while preserving the standard description of local physics.

    ↳ gr-qcastro-ph.COhep-phClass.Quant.Grav.(2026)·1 citation
61. 61*

    Calling the Brane Next Door: The Kaluza-Klein Tower as a Gravitational Information Channel

    Karim Benakli🇫🇷

    Could two worlds localised on neighbouring branes communicate through gravity alone? We investigate this question in a minimal higher-dimensional framework in which Standard Model fields are confined to our brane while gravity propagates through the bulk. From the brane-to-brane graviton propagator we derive the retarded transfer kernel of the inter-brane link and identify the transition from evanescent to propagating Kaluza-Klein modes. The central idea is to give the Kaluza-Klein tower a new role: not only as a spectrum of massive gravitational states, but as a set of communication carriers. Below the first KK threshold the channel is effectively four-dimensional and is mediated only by the massless graviton. Above threshold, massive KK modes open as additional propagating subchannels, and information may be encoded in their occupation pattern, relative phases, and arrival-time structure as well as in ordinary signal variables. The compactification determines the KK masses, wavefunctions, brane overlap factors, and propagation phases, which together define a multi-input multi-output (MIMO) channel matrix. In the resolved-mode limit, the tower yields approximate parallel subchannels, to which standard information-theoretic notions such as capacity bounds, water-filling, effective rank, and sparse occupancy codes apply. The production and detection of such signals are highly model-dependent and not assumed to be feasible with known technology. Nevertheless, the channel structure is well defined: a neighbouring brane-world could be separated from us by a microscopic distance in the compact space while remaining hidden because the only shared interaction is gravity. The first observable signature may not be a deliberate message, but the spectral and modal structure of the Kaluza-Klein tower itself, revealing partial information about the geometry of a nearby hidden world.

    ↳ hep-thcs.ITgr-qchep-ph+11 citation
62. 62*

    Resonance and Differential Reduction of Feynman Integrals

    Ruth Britto🇮🇪 · Thomas W. Grimm🇳🇱 · Arno Hoefnagels🇳🇱

    Feynman integrals may be viewed as generalized hypergeometric functions, and specifically as solutions of GKZ systems of partial differential equations that typically exhibit resonance. Resonance is a type of non-genericity implying reducibility to subsystems. We use this resonance to construct reduction operators, which are differential operators that can contract edges of Feynman graphs. Correspondingly, their action is naturally compatible with cuts of Feynman graphs. Reduction operators may be used to close the system of differential equations for a given integral. The remaining GKZ data lead to algebraic relations identifying a smaller system that is fully reduced to master integrals. We develop the construction for one-loop, sunrise and banana graphs and discuss restrictions to physical kinematics. While reduction operators can generally shift both propagator powers and spacetime dimension, certain combinations isolate a pure dimension shift together with contraction of a chosen edge.

    ↳ hep-thhep-phJHEP(2026)·0 citations
63. 63*

    Testing F-theory GUTs with the Axiverse

    Michael Nee🇺🇸 · Mario Reig🇨🇭 · Timo Weigand🇩🇪

    We show that axions coupled to photons in F-theory Grand Unified Theories (GUTs) satisfy the coupling-to-mass relation $g_{a\gamma }/m_a\le C\frac{{\alpha }_{\mathrm{em}}}{2\pi }\frac{1}{m_{\pi }{f}_{\pi }}$, with $C$ a calculable coefficient. This bound is saturated for the QCD axion with $C=\mathcal{O}(1)$ and holds in field theoretic and perturbative heterotic GUT constructions. In F-theory, topological GUT symmetry breaking by hypercharge flux introduces axion-like particles (ALPs) coupled to photons without coupling to QCD. These ALPs arise from the non-universal holomorphic threshold corrections to the gauge kinetic functions induced by the hypercharge flux. When gauge couplings approximately unify near the string scale, as required in phenomenologically viable models, the shift symmetries of these ALPs are broken by D-instantons whose action is controlled by the size of the threshold corrections to the gauge couplings. Small corrections imply unsuppressed instantons and heavy ALPs. We compute the resulting axion potentials and show that the coupling-to-mass ratio $g_{a\gamma }/m_a$ for every non-universal ALP lies well below the QCD axion prediction. We consider possible loopholes to this result -- some of which could lead to $C\gg 1$ -- and argue that none of them allows for $g_{a\gamma }/m_a$ to be arbitrarily above the QCD axion prediction within regions of control for the effective action. The bound persists in models with large threshold corrections, where new incomplete GUT multiplets at intermediate energy scales are required. As a result, in the geometric regime, where the ${\alpha }^{\prime }$ expansion is under control, no ALP parametrically above the QCD axion band exists. Our results make F-theory GUTs falsifiable: finding an ALP far above the QCD band, for example discovering axion-induced cosmic birefringence, rules out F-theory GUTs in regimes of control of the effective theory.

    ↳ hep-thhep-ph1 citation
64. 64*

    Tame the Umklapp Processes in Real-Time Lattice Simulation for Hydrodynamics: An Ising Field Theory Study

    Xiaojun Yao🇺🇸

    We calculate the real-time symmetric correlation function of the stress-energy tensor for a non-integrable Ising field theory consisting of three stable scalar particles via lattice Hamiltonian simulation. Using classical exact diagonalization and the matrix product state tensor network methods, we find that in the scaling region of the lattice theory, Umklapp processes are suppressed and the sound modes of relativistic hydrodynamics emerge at long wavelength and late time. The extracted ratio of bulk viscosity to entropy density is $\zeta /s=14.19\pm 0.90$ and the speed of sound is $c_s/c=0.76\pm 0.02$ at the temperature $T\approx 7.14$ in units of the lowest stable particle's mass. Our study demonstrates the utility of real-time lattice Hamiltonian simulation for describing hydrodynamization and calculating transport coefficients nonperturbatively.

    ↳ hep-latcond-mat.stat-mechhep-phquant-ph1 citation
65. 65*

    Testing Heavy Dark Matter Decay as the Origin of KM3-230213A

    KM3NeT Collaboration: O. Adriani🇮🇹 · J. A. Aguilar🇧🇪 · A. Albert🇫🇷 · A. R. Alhebsi🇺🇸 · S. Alshalloudi🇺🇸 · F. Ameli🇮🇹 · M. Andre🇪🇸 · L. Aphecetche🇫🇷 · M. Ardid · S. Ardid · J. Aublin🇫🇷 · F. Badaracco🇮🇹 and 277 other authors

    This work explores the hypothesis that the ultra-high-energy neutrino event KM3-230213A originates from the decay of a heavy dark matter particle with a mass above PeV scale. The analysis exploits the deposited energy and arrival direction of the event as well as a complete detector Monte Carlo simulation to compute the expected signal distributions for different decay channels and assesses the relative contributions from Galactic and extragalactic dark matter. Assuming a dark matter origin of the event, we find that the preferred mass at 95% C.L. is larger than about 100 PeV in all scenarios considered, with best-fit lifetimes in the range $10^{26}$-$10^{27}$ s. These preferred regions are in tension with existing bounds from other neutrino telescopes and gamma-ray observations.

    ↳ hep-exhep-ph4 citations
66. 66*

    On the potential of pseudo-scalar dark energy

    Andrea Minotti🇮🇹 · Yunzhi Wu🇮🇹 · Marco Regis🇮🇹

    A cosmological pseudo-scalar field provides a compelling realization of dynamical dark energy (DE). If its coupling to photons is non-negligible, the cosmic microwave background acquires a rotation of its polarization plane, known as cosmic birefringence (CB). We present an extended analysis of several pseudo-scalar DE models and derive constraints on the parameters of their potentials by combining observations of the background expansion history with measurements of CB. We find that the axion-like potential constitutes a viable model only for large values of the anomaly coefficient. Scenarios in which the pseudo-scalar field rolls down a potential with quadratic, linear, or Ratra-Peebles forms can successfully explain DE and CB, with a symmetry-breaking scale close to the GUT scale.

    ↳ astro-ph.COhep-ph0 citations
67. 67*

    Mixed Dark Matter: Limits from the Milky Way Satellite Galaxies

    Wendy Crumrine🇺🇸 · Dominic Pang🇺🇸 · Ethan O. Nadler🇺🇸 · Andrew Benson🇺🇸 · Vera Gluscevic🇺🇸

    The Standard Model of particle physics contains a diverse set of particle species, motivating the possibility of a similarly complex dark sector. Here we study two-component dark matter (DM) mixtures, in which one component behaves as standard CDM while the other suppresses the formation of small-scale structure, either through an astrophysically relevant de~Broglie wavelength (fuzzy DM; FDM) or collisional damping from temperature-independent scattering (interacting DM; IDM). Using the observed population of Milky Way satellite galaxies, we derive new leading constraints on the parameter spaces of mixed FDM and of mixed IDM coupled to photons ($\gamma$-DM), neutrinos ($\nu$-DM), or baryons ($p$-DM), for beyond-CDM fractions down to $50\%$. We require that the linear matter power spectra of allowed models remain less suppressed than a constrained reference model. The resulting $95\%$ confidence bounds on FDM mass and IDM cross section weaken systematically with decreasing fraction, following distinct power-law scalings. At $50\%$ fraction, IDM cross section bounds weaken by a factor of $\sim$2--6 and FDM mass bounds by $\sim$1.5, relative to the $100\%$ case. We forecast that idealized future satellite surveys, which adopt approximate LSST sensitivity thresholds, can improve these $100\%$ bounds by a factor of $\sim$1.6--14 for IDM and $\sim$3 for FDM. Self-consistent cosmological simulations of mixed DM scenarios will be essential to more robustly characterize the degeneracy between particle physics parameters and fractional contribution, to extend constraints to lower fractions, and to identify signatures beyond satellite abundance to further inform these models.

    ↳ astro-ph.COhep-ph3 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.