Tue·Jan 6, 2026Tuesday·January 6, 2026

1. 01*

   Distribution Amplitudes of Pseudoscalar Mesons within the Light-Front Quark Model

   Xiao-Nan Li🇨🇳 · Shuai Xu🇨🇳 · Qin Chang🇨🇳

   In this paper, we investigate the distribution amplitudes (DAs) of pseudoscalar mesons within the light-front quark model (LFQM), and the $n$-th Gegenbauer moment $a_n(\mu )$, $\xi$-moment $⟨{\xi }^n⟩$ and transverse moment $⟨{\mathbf{k}}_{\perp }^n⟩$ are also studied. Two parameter sets are adopted by fitting to mesonic decay constants or mass spectra, leading to distinct schemes for numerical analysis. Our results reveal several key insights: (1) Under scheme-I, the second Gegenbauer moment for the pion, $a_{2,\pi }=0.054$, is in excellent agreement with predictions from the platykurtic model and the nonlocal chiral quark model (NL$\chi$QM). Meanwhile, scheme-II yields $a_{2,\pi }=0.126$, which is consistent with lattice QCD (LQCD), Dyson-Schwinger equation (DSE) and data-driven light-cone sum rules (LCSR) analyses. Furthermore, we observe that ${\varphi }_{2,\pi }={\varphi }_{3,\pi }^P$ with the replacement $M\to M_0$. (2) Flavor symmetry breaking effects are found to be more significant in higher-twist DAs, with a notable relation $a_1^P\approx 2a_1$ emerging in heavy meson systems. (3) Interestingly, numerical analysis indicates that the transverse moment $⟨{\mathbf{k}}_{\perp }^n⟩$ is twist-independent with the replacement $M\to M_0$. Additionally, we propose an empirical scaling relation $\frac{\Delta m^{0.61}}{{\beta }^{1.10}}{x}_p=0.67$ to effectively describe the shape of DAs for heavy mesons. Collectively, these results demonstrate that mass asymmetry remarkably influences DAs and kinds of moments, these theoretical predictions will be tested in future experiments.

   hep-phPRD(2026)·3 citations
2. 02*

   Search for Axions and Dark Photons Using Single Molecule Magnets

   Jose R. Alves🇧🇷 · Manfred Lindner🇩🇪 · Farinaldo S. Queiroz🇧🇷 · Manoel S. Vasconcelos🇧🇷

   Molecular magnets, although analogous to familiar macroscopic magnets, offer a platform for next generation magnetic storage technologies with far higher data densities and prospective applications in quantum information science. When exposed to an external magnetic field, single molecule magnets enter a frustrated magnetic configuration that is exceptionally sensitive to low energy excitations. Energy deposited by a dark matter particle can trigger the relaxation of a metastable molecule, releasing Zeeman energy that subsequently propagates through neighboring molecules. This magnetic avalanche encodes the energy deposited in the initial excitation. By combining concepts from chemistry, condensed matter physics, and particle physics, we show that dysprosium and manganese molecules can achieve more than an order of magnitude improvement in sensitivity to dark photon and QCD axion models, respectively, compared with existing detection methods.

   hep-phcond-mat.mtrl-scihep-exhep-th3 citations
3. 03*

   Supersymmetry at High Luminosity LHC

   Kairui Zhang🇺🇸

   Weak-scale supersymmetry (SUSY) is well motivated as a technically natural solution to the gauge hierarchy problem. LHC limits on superpartners, however, have sharpened the Little Hierarchy problem, raising the question of why $m_{weak}\ll m_{soft}$. We review current collider and dark matter constraints and their implications for leading SUSY-breaking scenarios. Electroweak naturalness is revisited using a weak-scale measure that avoids ambiguities associated with high-scale fine-tuning. Also, within the string landscape, soft terms are statistically favored to be large, while anthropic selection enforces a weak scale near the observed value. This framework often termed \emph{stringy naturalness} -- naturally accommodates $m_h\simeq 125$ GeV while placing sparticles above current LHC limits. Updated HL-LHC projections for non-universal Higgs mass (NUHM) models -- the most plausible realization consistent with above picture -- show that searches for higgsinos, stops, and heavy Higgs bosons will soon begin to probe the core of the viable parameter space.

   hep-ph2 citations
4. 04*

   Singly heavy Cascade Baryon ${\Xi }_c^0$ \& ${\Xi }_b^{-}$ Spectroscopy in the Relativistic Framework of Independent Quark Model

   Rameshri V. Patel🇮🇳 · Manan Shah🇮🇳 · Bhoomika Pandya🇪🇸

   In this work, the potential parameters of the independent quark model are systematically reduced using previously determined inputs from a broad range of baryons. The reduced-parameter formulation, developed within the relativistic Dirac formalism and employing a Martin-like potential, is then applied to the spectroscopy of the singly heavy baryons ${\Xi }_c^0$ and ${\Xi }_b^{-}$. This enables an explicit verification of the linear relation obtained between the potential parameters. Radially and orbitally excited state masses are calculated, and the resulting Regge trajectories are used to assign spin-parity to experimentally observed states. The states ${\Xi }_c^0(2923)$, ${\Xi }_c^0(3080)$, ${\Xi }_c^0(2882)$, and ${\Xi }_c^0(2970)$ are identified as having $J^P={\frac{1}{2}}^{-}$, ${\frac{3}{2}}^{+}$, ${\frac{3}{2}}^{-}$, and ${\frac{1}{2}}^{+}$, respectively, while the observed ${\Xi }_b^{-}(6227)$ state is assigned $J^P={\frac{5}{2}}^{+}$. To investigate the electromagnetic structure of these baryons, their magnetic moments and radiative decay widths are computed. Additionally, the two-body weak decay branching ratios of ${\Xi }_c^0$ are evaluated and contrasted with experimental data to assess the robustness of the approach. The two-body nonleptonic decays of ${\Xi }_b^{-}$ are also analyzed, providing predictions for branching ratios that may be tested in future experiments. Overall, the results demonstrate the effectiveness of the parameter-reduction procedure and support its applicability in the spectroscopy of baryons.

   hep-phEPJC(2026)·0 citations
5. 05*

   Time-like electromagnetic form factors of $\Lambda ,\Sigma$ and ${\Xi }^{+}$ in a light-front quark model

   Chong-Chung Lih🇨🇳 · Chao-Qiang Geng🇨🇳

   We use the light front quark model to investigate the form factors in the $e^{+}{e}^{-}\to B\bar{B}$ collision proceses with $B=\Lambda ,\Sigma$ and $\Xi$. These form factor behaviors are calculated based on the Bethe-Salpeter formalism with $q^{+}>0$ to effectively account for non-valence contributions. We show that our results of the $q^2$-dependent form factors closely match the BESIII data. In particalar, we obtain that $|G_{eff}|=(0.921,0.098,0.189$) and $R=|$$\frac{G_E}{G_M}$$|=(0.97,0.89$,~$0.936$) for $e^{+}{e}^{-}\to \Lambda \bar{\Lambda }$,~${\Sigma }^{+}{\Sigma }^{-},{\Xi }^{+}{\Xi }^{+})$ which $q^2=(5.74,6.0,7.0)$ GeV${}^2$.

   hep-phhep-exPRC(2026)·2 citations
6. 06*

   Quantum Chromodynamics at the Large Hadron Collider

   Jesse Liu (for the ALICE, ATLAS, CMS and LHCb Collaborations)🇺🇸

   Open questions on the fundamental nature of the strong force endure and the Large Hadron Collider (LHC) is a once-in-a-generation laboratory elucidating its quantum origins. This document summarizes the plenary overview talk titled "QCD Studies at the LHC" presented at the Lepton Photon Symposium 2025. Selected results highlight recent experimental advances in Quantum Chromodynamics (QCD) at the LHC. This reviews the breadth of QCD and its cross-cutting synergies from a particle physics perspective in four themes: terascale precision tests, non-perturbative enigmas, mystery of confinement, and extreme cosmic-ray puzzles.

   hep-phhep-ex0 citations
7. 07*

   First Constraints on Long-Range Neutrino Interactions using IceCube DeepCore

   Gopal Garg🇮🇳 · J Krishnamoorthi🇮🇳 · Anil Kumar🇮🇳 · Sanjib Kumar Agarwalla🇮🇳

   We present the first search for new flavor-dependent long-range interactions (LRI) of neutrinos using publicly available 8 years of high-purity ${\nu }_{\mu }$ CC data from IceCube DeepCore. These interactions are mediated by ultra-light gauge bosons with masses below $10^{-10}$ eV, which can arise due to a new lepton-number gauge symmetry, such as $L_e-L_{\mu }$ or $L_e-L_{\tau }$. These long-range interactions induce matter potential between neutrinos and abundant electrons present in distant astrophysical sources. These LRI potentials could modify neutrino oscillation probabilities. By probing the effects of LRI on atmospheric neutrino oscillations at IceCube DeepCore, we place world-leading constraints on the coupling strength of these interactions.

   hep-phhep-exphysics.ins-det3 citations
8. 08*

   $B_c$ meson decays into $S$-wave charmonium plus light meson pairs in the perturbative QCD approach

   Jia-Ying Wang (Nanjing Agricultural U.)🇨🇳 · Jing Jiang (Nanjing Agricultural U.)🇨🇳 · Yu-Jie Liu (Nanjing Agricultural U.)🇨🇳 · Da-Cheng Yan (Changzhou U.)🇨🇳 · Zhou Rui (Yantai U.)🇨🇳 · Zhen-Jun Xiao (Nanjing Normal U.)🇨🇳 · Ya Li (Nanjing Normal U.)🇨🇳

   In this work, we explore the $P$-wave resonance contributions to the three-body charmonium decays of $B_c\to \Psi (V\to )P_1{P}_2$ using the perturbative QCD formalism at leading order, where $\Psi$ denotes a $S$-wave charmonium state, such as ${\eta }_c(1S,2S),J/\psi$, and $\psi (2S)$. Here, $P_1{P}_2$ represents a collinear $\pi \pi$ ($K\pi$) pair in the final state, which was primarily produced through the vector resonance $\rho (770)$ ($K^{\ast }(892)$ ). With the improved two-meson distribution amplitudes determined from our previous works, we examined the $CP$-averaged branching ratios and polarization fractions of the considered three-body decays. The longitudinal polarization fractions of the $B_c\to [J/\psi ,\psi (2S)](V\to )P_1{P}_2$ decays are found to be as large as $\sim 90\%$, since the transverse amplitudes from the dominant factorizable emission diagrams are always power suppressed with respect to the longitudinal ones. The direct $CP$ violations in $B_c\to \Psi (V\to )P_1{P}_2$ decays are predicted naturally to be zero as they solely receive contributions from tree diagrams. Several interesting relative ratios among the branching fractions of the concerned processes are investigated. In particular, the obtained ratio $R_{2\pi /\pi }^{\mathrm{PQCD}}\equiv \mathcal{B}(B_c^{+}\to J/\psi (\rho \to ){\pi }^{+}{\pi }^0)/\mathcal{B}(B_c^{+}\to J/\psi {\pi }^{+})=2.67_{-0.14}^{+0.21}$ is consistent well with the LHCb measurement $R_{2\pi /\pi }^{\exp }=2.80\pm 0.25$. Other similar ratios proposed in this work can be tested by LHCb experiments in the near future.

   hep-phEPJC(2026)·1 citation
9. 09*

   Investigating $\Omega \varphi$ Interaction and Correlation Functions

   Ye Yan · Yuheng Wu · Yue Tan · Qi Huang · Hongxia Huang · Jialun Ping

   In this work, we investigate the interaction between the $\Omega$ baryon and the $s\bar{s}$ meson within the framework of the quark delocalization color screening model. The spectra calculations show that no bound state is formed in any of the considered channels, while the scattering indicates that the $\Omega \varphi$ interaction with $J^P=1/2^{-}$ is weakly attractive. As for the $\Omega \varphi$ interactions with $J^P=3/2^{-}$ and $5/2^{-}$, as well as the $\Omega {\eta }^{\prime }$ interaction with $J^P=3/2^{-}$, they are all repulsive. After an investigation on the femtoscopic correlation functions, we find that, due to the spin-averaging effect, the overall $\Omega \varphi$ correlation function exhibits a weak dependence on the source size, which provides a crucial significance of our model for future experimental examinations in relativistic heavy-ion collisions.

   hep-phhep-exhep-latnucl-thPRC(2026)·4 citations
10. 10*

    Finding a clean process $B^{-}\to K^{-}{D}^0{K}^0$ to probe absolutely exotic four-quark states

    Man-Yu Duan🇨🇳 · Guan-Ying Wang🇨🇳 · Yun Liang🇨🇳 · En Wang🇨🇳 · Xiang Liu🇨🇳 · Dian-Yong Chen🇨🇳

    Motivated by the observations of $T_{c\bar{s}0}(2900{)}^0$ and $T_{c\bar{s}0}(2900{)}^{++}$, we propose to search for ${\text{tcsbar}}^0$ in the cleaner process $B^{-}\to K^{-}{D}^0{K}^0$. In the $D^{\ast }{K}^{\ast }$ molecular picture, our estimates suggest that $T_{c\bar{s}0}(2900{)}^0$ should contribute significantly to the $D^0{K}^0$ invariant mass distribution in $B^{-}\to K^{-}{D}^0{K}^0$, as reported by the Belle II Collaboration. The corresponding fit fraction is estimated to be $(9.72\pm 3.92)\%$ or $(7.09\pm 5.88)\%$ in different fitting schemes. Further precise measurements of this process at Belle II and LHCb could be helpful for clarifying the nature of $T_{c\bar{s}0}(2900)$.

    hep-phPRD(2026)·0 citations
11. 11*

    Topology-Informed Jet Tagging using Persistent Homology

    Saurav Mittal🇯🇵

    We present a topology-informed approach for classifying particle jets using persistent homology, a framework that captures the structural properties of point clouds. Particle jets produced in proton-proton collisions consist of cascades of particles originating from a common hard interaction. Each jet constituent is represented as a point in a three-dimensional feature space defined by the relative transverse momentum and angular coordinates with respect to the jet axis, yielding a point cloud description of each jet. Persistent homology is computed using a Vietoris-Rips filtration to obtain persistence diagrams, which are subsequently converted into persistence images for the H0 and H1 homology groups, corresponding to connected components and loop-like structures, respectively. These persistence images are used as inputs to a convolutional neural network for quark-gluon jet classification. Using the publicly available HLS4ML jet dataset, we find that persistence images derived from H0 and H1 individually exhibit comparable discriminative power. These results demonstrate that loop-like topological features, which are not conventionally exploited in jet tagging, encode meaningful information about jet substructure and provide a promising direction for topology-informed jet classification.

    hep-ph1 citation
12. 12*

    Unitarity constraints on 2HDM with higher dimensional operators

    Deepak Sah🇮🇳

    We study how the requirement of perturbative unitarity restricts the parameter space of the two-Higgs-doublet model (2HDM) when higher-dimensional operators up to dimension six are included. We demonstrate that such operators can enhance scalar production cross sections in vector boson fusion relative to 2HDM. Using S-matrix unitarity, we place bounds on several dimension-six bosonic operators. We also find that certain blind directions in the Wilson coefficients of T-parameter violating operators which are poorly constrained by electroweak precision data can be partially excluded when unitarity constraints are taken into account. These results demonstrate how high-energy consistency can complement experimental limits in defining the allowed parameter space of 2HDM effective field theory.

    hep-phhep-th1 citation
13. 13*

    On electric fields in hot QCD: infrared regularization dependence

    Gergely Endrődi🇩🇪 · Gergely Markó🇩🇪 · Leon Sandbote🇫🇮

    We study the impact of background electric fields on a hot plasma of charged particles -- a setting relevant for the early stages of heavy-ion collisions as well as laser pulse experiments. Historically, the electric susceptibility -- encoding the behavior of the hot medium for weak fields -- has been defined within two different formalisms, leading to two distinct results at nonzero temperature. With the help of an exact fermion propagator in a homogeneous electric background field at nonzero temperature and finite volume on the one hand, and an improved perturbative result on the other, we identify the origin of this disagreement. The equilibrium conditions for the system are discussed and the role of the thermodynamic ensemble used to describe the system is highlighted. Finally, we construct the electric susceptibility in a simplified hadron resonance gas model, relevant for the strongly interacting medium in the low-temperature regime.

    hep-phhep-lathep-thJHEP(2026)·3 citations
14. 14*

    Discovering the Gell-Mann-Okubo Formula with Kolmogorov-Arnold Networks

    Jian-Yao He🇨🇳 · Xun Chen🇨🇳 · Xiao-Yan Zhu🇨🇳 · Wen Luo🇨🇳

    Uncovering physical laws from experimental data is a fundamental goal of theoretical physics. In this work, we apply the spline-based, interpretable Kolmogorov-Arnold Network (KAN) to explore the algebraic structure underlying the baryon octet and decuplet mass spectra. Within a symbolic regression framework and without imposing theoretical priors, KAN autonomously recovers the classical Gell-Mann-Okubo mass relations and accurately extracts the associated SU(3) symmetry-breaking parameters. Compared to conventional fitting approaches, this method achieves comparable predictive accuracy while offering substantially improved interpretability and analytic transparency. Our results demonstrate the potential of KAN as a powerful tool for symbolic discovery in hadron physics and for bridging data-driven modeling with fundamental physical laws.

    hep-ph1 citation
15. 15*

    Top-quark pair production in electron-positron collisions within the minimal noncommutative Standard Model

    Fatma Zohra Bara🇩🇿 · Slimane Zaiem🇩🇿 · Yazid Delenda🇩🇿

    We study top-quark pair production in electron-positron collisions within the framework of the minimal noncommutative Standard Model. Noncommutative effects are incorporated using the Seiberg-Witten map, and the scattering squared amplitude for the process $e^{+}{e}^{-}\to t\bar{t}$ is computed consistently up to second order in the noncommutativity parameter ${\Theta }^{\mu \nu }$. We derive the total cross-section, the polar and azimuthal angular distributions, and the forward-backward asymmetry, all of which exhibit sensitivity to space-time noncommutativity. Numerical results are evaluated for center-of-mass energies relevant to future linear colliders, such as the ILC and CLIC. Our analysis demonstrates that noncommutative geometry can induce significant characteristic deviations from the Standard Model predictions, offering a potential indirect probe of space-time noncommutativity at high-energy $e^{+}{e}^{-}$ collisions.

    hep-phModern Physics Letters A(2026) 2650155·0 citations
16. 16*

    Unraveling Dirac Magnetic Monopoles with Muon Beams at TeV Energies Using Machine Learning

    M. Tayyab Javaid🇵🇰 · Mudassar Hussain🇵🇰 · Haroon Sagheer🇵🇰 · M.Danial Farooq🇵🇰 · Ijaz Ahmed🇵🇰 · Jamil Muhammad🇰🇷

    The focus of this paper is the production of magnetic monopoles Drell-Yan and the Photon-Fusion mechanisms to generate velocity-dependent scalar, fermionic, and vector monopoles of spin angular momentum $0,\frac{1}{2},1$ respectively at a future muon collider. A computational study compares the monopole pair-production cross-sections for both methods at various center-of-mass energies ($\sqrt{s}$) with different magnetic dipole moments. The comparison of kinematic distributions of monopoles at the generator and reconstructed level is demonstrated for both DY and PF mechanisms. We demonstrate the observability of magnetic monopoles against the most relevant Standard Model background using multivariate analysis techniques. Specifically, we apply three different classifiers based on neural networks, e.g., Boosted Decision Trees, Multilayer Perceptrons, and Likelihood methods, to evaluate their effectiveness. Our results highlight the efficiency and robustness of these approaches in distinguishing magnetic monopole signals from background noise.

    hep-ph0 citations
17. 17*

    A Geometric Interpretation of Heavy-Quark Transitions and the Emergent SU(2) Structure

    Jorge Gamboa🇨🇱 · Natalia A. Tapia Arellano🇺🇸

    We propose a geometric interpretation of heavy-light mesons in which their infrared dressing is described through adiabatic Berry holonomies on the functional space of gauge configurations. Within this framework the Berry curvature associated with the infrared cloud carries a quantized functional flux, providing a simple and structural origin for the exponential form of the Isgur-Wise function in single-recoil transitions. Sequential processes such as $B\to D^{\ast \ast }\to D$ probe two independent recoil directions and explore a two-dimensional region of the adiabatic manifold. In this setting the quantized flux naturally leads to a minimal non-Abelian structure which can be described effectively by an SU(2) holonomy. Heavy-quark form factors then appear as channel-dependent projections of two universal geometric modes, giving rise to correlated slopes, non-factorizable curvature in the $(w_1,w_2)$ plane, and characteristic angular patterns. These features are consistent with the symmetry structure of HQET while providing additional correlations among excited channels. The resulting framework offers a complementary viewpoint on heavy-quark phenomenology and suggests several experimentally testable signatures in multi-step semileptonic transitions.

    hep-phhep-th0 citations
18. 18*

    Notes on Magnetic Monopoles from Partial Electromagnetic Duality

    Yanfeng Hang🇺🇸

    In this work, we propose a novel partial electromagnetic duality and construct its consistent realization using an extended gauge group $\mathrm{U}(1{)}_{\mathrm{q}}^{}\otimes \mathrm{U}(1{)}_{\mathrm{d}}^{}$ over a localized space region, where $\mathrm{U}(1{)}_{\mathrm{q}}^{}$ is the conventional gauge group of QED and $\mathrm{U}(1{)}_{\mathrm{d}}^{}$ serves as its dual gauge group. In this framework, the "electric" charge associated with $\mathrm{U}(1{)}_{\mathrm{d}}^{}$ plays the role of the magnetic (monopole) charge in QED $\mathrm{U}(1{)}_{\mathrm{q}}^{}$, whereas the electric charge of $\mathrm{U}(1{)}_{\mathrm{q}}^{}$ is reinterpreted as the "magnetic" charge of $\mathrm{U}(1{)}_{\mathrm{d}}^{}$. Importantly, our theory preserves the exact Bianchi identity, as it provides a genuinely singularity-free and stringless formulation that involves only electric charges under each U(1) gauge group. We show that the two gauge sectors, $\mathrm{U}(1{)}_{\mathrm{q}}^{}$ and $\mathrm{U}(1{)}_{\mathrm{d}}^{}$, exhibit a partial duality within a localized region of space. Based on this consistent formulation, we present the first fully gauge-invariant computation of scattering amplitudes and cross sections for monopole production processes, including ${\mathrm{e}}^{-}{\mathrm{e}}^{+}\to \chi {\chi }^{\ast }$ and ${\mathrm{e}}^{-}{\mathrm{e}}^{+}\to \chi \bar{\chi }$.

    hep-ph0 citations
19. 19*

    Asymmetric Dark Matter from Low-Scale Spontaneous Leptogenesis

    Hiroki Takahashi🇯🇵 · Juntaro Wada🇯🇵

    We investigate a novel type of asymmetric dark matter (ADM) model in which the dark matter asymmetry and the baryon asymmetry in our universe (BAU) are produced simultaneously via low-scale spontaneous leptogenesis, where the mass scale of right-handed neutrino is much lower than the Davidson-Ibarra bound $M_1\ll 10^9\mathrm{GeV}$. In our scenario, both asymmetries are predominantly sourced by a dynamical $CP$ phase, namely the majoron. Its kinetic misalignment provides a sufficiently large, time-dependent effective $CP$ phase, allowing efficient asymmetry production even for low-scale right-handed neutrinos. In our framework, the sources of $CP$ violation responsible for the BAU and ADM are correlated with each other, leading to a predictive relation for the dark matter mass. In particular, when the dark matter asymmetry reaches its equilibrium value before freeze-out, the dark matter mass is typically predicted to lie in the range $\mathcal{O}(0.1)\mathrm{GeV}\lesssim m_{\chi }\lesssim \mathcal{O}(100)\mathrm{GeV}$, which lies within the sensitivity of direct detection experiments. On the other hand, if the dark matter asymmetry does not reach its equilibrium value due to weak coupling, the allowed mass range extends over a broader interval, $\mathcal{O}(0.1)\mathrm{GeV}\lesssim m_{\chi }\lesssim \mathcal{O}(10)\mathrm{TeV}$.

    hep-phastro-ph.COhep-th8 citations
20. 20*

    Color-Singlet and Color-Octet Quark Matters

    Cheuk-Yin Wong🇺🇸

    Quarks and antiquarks carry color and electric charges and belong to the color-triplet $3$ group and the color-antitriplet $\bar{3}$ group respectively. The product groups of $3$ and $\bar{3}$ consist of the color-singlet $1$ and the color-octet $8$ subgroups. Therefore, quarks and antiquarks combine to form color-singlet $[q\bar{q}{]}^1$ quark matter and color-octet $[q\bar{q}{]}^8$ quark matter. The color-octet quark matter corresponds to the $q\bar{q}$ quark matter as envisaged in the realm of present knowledge but the color-singlet quark matter is as yet unexplored and now submitted for exploration. The color-singlet quark matter with two flavors can be separated into charged and neutral color-singlet quark matters. In the neutral color-singlet quark matter, the quark and the antiquark interacting only in the QED interaction may form stable and confined colorless QED mesons non-perturbatively at about 17 MeV and 38 MeV (PRC81,064903(2010) and JHEP(2020(8),165). It is proposed that the possible existence of the QED mesons may be a signature of the neutral color-singlet quark matter at $T=0$. The observations of the anomalous soft photons at CERN, and the anomalous bosons with mass about 17 MeV at ATOMKI, DUBNA, and HUS, and mass about 38 MeV at DUBNA hold promising experimental evidence for the existence of such QED mesons, pending further confirmations.

    hep-phastro-ph.HEhep-thnucl-thUkr.J.Phys.(2026)·0 citations
21. 21*

    NNLOCAL: Completely Local Subtractions

    Vittorio Del Duca🇮🇹 · Claude Duhr🇩🇪 · Levente Fekésházy🇩🇪 · Flavio Guadagni🇨🇭 · Pooja Mukherjee🇩🇪 · Gábor Somogyi🇭🇺 · Francesco Tramontano🇮🇹 · Sam Van Thurenhout🇭🇺

    The computation of higher-order corrections to cross sections relevant at LHC involves the evaluation of phase-space integrals that exhibit soft and collinear divergences. The subtraction of these divergences is a key ingredient to obtain fully-differential predictions for physical observables. We discuss a subtraction method to handle these divergences based on the construction of universal local counterterms. The integration of the counterterms is carried out analytically, giving a strong control on the numerical stability of our predictions. We implement our method in a numerical program, that we dub NNLOCAL, and validate it by computing the fully-differential NNLO cross-section for Higgs boson production in gluon-gluon fusion.

    hep-phPoS(2026)·3 citations
22. 22*

    Resonant Photon-Axion Mixing Driven by Dark Matter Oscillations

    Run-Min Yao🇨🇳 · Xiao-Jun Bi🇨🇳 · Peng-Fei Yin🇨🇳 · Qing-Guo Huang🇨🇳

    Wave propagation in periodically time-dependent media can exhibit driven mode conversion that is absent in static or adiabatic descriptions. We show that photon propagation through a coherent axion dark matter background provides a natural realization of such driven dynamics. In the presence of a magnetic field, the oscillating axion field acts as a coherent temporal drive, inducing resonant photon-axion conversion when the mismatch between their dispersion relations is compensated by integer harmonics of the axion oscillation frequency, ${\Delta }_{\gamma }-{\Delta }_a\approx n{m}_a$ with $n\in \mathbb{Z}$. This driven resonance enables efficient mixing far from the conventional level-crossing regime and disappears entirely upon time averaging, explaining why it is missed in standard treatments. The process constitutes a unitary mode-conversion phenomenon that preserves the axion dark matter number density and is distinct from parametric instabilities or axion decay. A systematic description is naturally provided by Floquet theory. We develop a general framework for photon propagation in oscillating axion backgrounds and show that the resulting resonant mixing leads to characteristic polarization signatures, with potential implications for astrophysical observations such as blazar polarization.

    hep-phastro-ph.HE3 citations
23. 23*

    Anti-collinear resummation in JIMWLK evolution in the linear regime

    Alex Kovner🇺🇸 · Michael Lublinsky🇮🇱 · Maxim Nefedov🇮🇱 · Vladimir Skokov🇺🇸

    The recently-proposed resummation procedure for anti-collinear logarithms in the JIMWLK kernel~\cite{Kovner:2023vsy} is studied in the linear (BFKL) regime in the fixed-coupling approximation. Simple closed form expressions for the resummed momentum space kernel and characteristic function $\chi (n,\gamma )$ are found. We find that the anti-collinear pole in the leading order characteristic function at $\gamma =1$ disappears, and instead $\chi (\gamma =1)=\frac{12}{11}\frac{\pi }{{\alpha }_s{N}_c}$ for $n_F=0$. Comparison with the known NLO BFKL eigenvalue, with the target-Bjorken limit ($Q_T\gg Q_P$) of the ${\gamma }^{\ast }(Q_P)+{\gamma }^{\ast }(Q_T)$-scattering amplitude and with the ``all-poles'' resummation prescription are presented.

    hep-phhep-thnucl-thJHEP(2026)·1 citation
24. 24*

    Electroweak precision tests for asymptotic Grand Unification models

    Giacomo Cacciapaglia🇫🇷 · Aldo Deandrea🇫🇷 · Christian Verollet🇫🇷

    Asymptotic grand unification is an alternative framework to traditional quantitative unification, as the renormalisation flow leads towards an ultra-violet safe fixed point. Phenomenologically, 5-dimensional realisations permit new particles with masses as low as the TeV scale, well below the usual unification scale. We explore the impact of such models on electroweak precision observables, focusing on a minimal SU(5) template for concreteness. We show that current measurements are not sensitive to this class of models. Future colliders, such as CEPC and FCC-ee, can push the 95% limit on the Kaluza-Klein mass up to 2 and 4 TeV, respectively, beyond the direct reach of the LHC programme.

    hep-phJHEP(2026)·0 citations
25. 25*

    Spin-Orbit Correlations in the Pion and the Role of Quark-gluon Interaction

    Poonam Choudhary🇮🇳 · Asmita Mukherjee🇮🇳 · Ravi Singh🇮🇳

    We study the spin-orbit correlations (SOCs) of the pion using overlap of light-front wave functions (LFWFs). Going beyond the leading Fock sector, we incorporate one gluon in the wave function. The analytic form of the higher Fock component of the LFWF is constructed by incorporating a perturbative gluon to the pion state. This allows us to explore the role of quark-gluon interactions in the spin-orbit correlation within a model calculation. We investigate the kinetic and canonical spin-orbit correlations of quarks in the pion, which arise from different decompositions of the energy-momentum tensor. We further explore the difference between kinetic and canonical SOC arising from the inclusion of higher Fock sector containing gluon.

    hep-ph1 citation
26. 26*

    ${\Lambda }_b\to \Lambda$ Form Factors from Light-Cone Sum Rules with $\Lambda$-Baryon Distribution Amplitudes

    F. Mahmoudi🇫🇷 · D. Mishra🇫🇷

    We compute the ${\Lambda }_b\to \Lambda$ transition form factors using light-cone sum rules based on $\Lambda$-baryon distribution amplitudes, including contributions up to twist--6. The analysis is performed for pseudoscalar, vector, and axial-vector $b\to s$ currents and for different choices of the ${\Lambda }_b$ interpolating current. We find that only the pseudoscalar interpolating current leads to numerically stable and phenomenologically viable form factors. The resulting form factors are parametrised using a $z$-expansion and applied to the rare decay ${\Lambda }_b\to \Lambda {\ell }^{+}{\ell }^{-}$, yielding predictions for branching ratios in the low-$q^2$ region.

    hep-ph1 citation
27. 27*

    Research of the Behavior of the Effective Potential in Systems with Phase Transitions through the Prism of A--D--E Type Singularities

    T. V. Obikhod🇺🇦

    Detecting a scalar singlet interacting through the Higgs portal demands a pivot from conventional particle detection strategies to a comprehensive examination of the effective potential's landscape. The presence, intensity, and first-order nature of the electroweak phase transition are dictated by the critical manifold, with its universal traits encapsulated in the Milnor number $\mu$ -- the dimensionality of the local Jacobian algebra. Throughout the parameter space consistent with experimental observations, the portal potential exhibits a non-simple singularity with $\mu =9$, maintaining topological stability amid substantial fluctuations in mixing angle, singlet mass, and cubic interactions. High-precision assessments of the Higgs trilinear self-coupling (${\kappa }_{\lambda }$), the uniform rescaling of Higgs couplings ($c_H$), and the stochastic gravitational-wave spectrum (${\Omega }_{\mathrm{GW}}$) collectively delineate the catastrophe, extending beyond mere mass matrix analysis. Projections for 2027--2040 collider and LISA capabilities indicate that no viable region supporting a strong first-order transition will evade scrutiny; thus, the singlet will either be identified or conclusively dismissed via direct interrogation of the electroweak vacuum's critical structure.

    hep-phhep-thScience, Technology, and Innovation, Part…·0 citations
28. 28*

    On the Stability of Leading-Power Factorization under Photon Propagator Numerator Modifications

    Cong Li🇨🇳

    We study collinear factorization in strong electromagnetic backgrounds within SCET for a class of modifications where the photon propagator keeps the vacuum pole structure and $i\epsilon$ prescription, while the background enters only through a numerator tensor ${\Delta }_{\mu \nu }(k)$. We show that the set of Landau pinch surfaces and leading momentum regions is unchanged, so the leading-power (LP) factorized form is preserved. Moreover, the LP cusp kernel depends on the background solely through the longitudinal contraction $n^{\mu }{\bar{n}}^{\nu }{\Delta }_{\mu \nu }(k)$ in the soft region; if it vanishes (or is power suppressed), the LP soft kernel reduces to the vacuum. As an application, for an occupancy-number modification with the physical polarization-sum tensor $g_{T\mu \nu }(k;n)$, transversality implies $n^{\mu }{\bar{n}}^{\nu }{\Delta }_{\mu \nu }=0$, so genuine background sensitivity starts only beyond LP.

    hep-phhep-th0 citations
29. 29*

    Fixed points of the renormalisation group running of quark and fermion mixing matrices in the Standard Model and beyond

    Brian P. Dolan🇮🇪

    The renormalisation group running of fermion mixing matrices in the Standard model and beyond is studied. For the massless 1-loop running with three generations six fixed points are found. Their associated anomalous dimension matrices are calculated and the nature of each fixed point, whether attractive, repulsive or mixed, is determined. An argument is given that the fixed points found at 1-loop must remain fixed points to all orders in perturbation theory and even non-perturbatively, as they are associated with certain differential geometric properties of vector fields on the space of mixing matrices. With $N_g$ dark or sterile neutrinos there are at least $N_g!$ fixed points of the fermion mixing matrix.

    hep-phhep-thPRD(2026)·2 citations
30. 30*

    GeV-scale QCD Axion

    Hitoshi Murayama🇺🇸

    In order to solve the strong CP problem, we study the possibility that the Peccei--Quinn symmetry is broken {\it below}\/ the QCD scale. We find that a QCD axion can be above GeV, and may be among the observed $\eta$ resonances. It is immune to quantum gravity corrections. The only fermion that has a $U(1)$ Peccei--Quinn charge is the right-handed up quark. Flavor-changing neutral currents are surprisingly small. All accelerator and astrophysical limits can be evaded. The most significant constraint is the mass splitting between ${\pi }^{\pm }$ and ${\pi }^0$. In a UV completed model, LHC can look for a heavy quark pair $\mathcal{D}\overline{\mathcal{D}}$ followed by the decay $\mathcal{D}\to W+u$ or a single production $qu\to q\mathcal{U}$ followed by $\mathcal{U}\to uZ,uh$. There can be an $O(1)$ contribution $h\to u\bar{u}\phi$ in the measurement of $h\to gg$ or permille effects on the hadronic $Z$ width at a Higgs factory.

    hep-phhep-ex11 citations
31. 31*

    Probing Dark Matter-Electron Interactions with Superconducting Qubits

    Yonit Hochberg🇮🇱 · Majed Khalaf🇮🇱 · Noah Kurinsky🇺🇸 · Alessandro Lenoci🇮🇱 · Rotem Ovadia🇮🇱

    Quantum device measurements are powerful tools to probe dark matter interactions. Among these, transmon qubits stand out for their ability to suppress external noise while remaining highly sensitive to tiny energy deposits. Ambient galactic halo dark matter interacting with electrons can deposit energy in the qubit, leading to changes in its decoherence time. Recent measurements of transmons have consistently measured, in various experimental setups, a residual contribution to the decoherence time unexplained by thermal noise or known external sources. We use such measurements to set the most stringent laboratory-based constraints to date on dark matter-electron scattering at the keV scale and competitive constraints on dark photon absorption.

    hep-phhep-exquant-ph3 citations
32. 32*

    Resummation of the C-Parameter Sudakov Shoulder Using Effective Field Theory

    Matthew D. Schwartz🇺🇸

    The C-parameter distribution in $e^{+}{e}^{-}$ annihilation exhibits a kinematic shoulder at $C=3/4$, where three-parton final states reach their maximum and a fourth parton is required to exceed it. This boundary generates large logarithms that must be resummed. Using soft-collinear effective theory, we derive a factorization theorem involving new jet and soft functions specific to the C-parameter measurement, in which soft radiation contributes quadratically in transverse momentum. This quadratic structure explains the step discontinuity at leading order. We compute all ingredients at one loop, validate against Monte Carlo, and present matched NLL+NLO results. Unlike thrust and heavy jet mass, the C-parameter has no Sudakov--Landau pole, making momentum-space resummation straightforward. All calculations, numerical analysis, and manuscript preparation were performed by Claude, an AI assistant developed by Anthropic, working under physicist supervision.

    hep-phhep-th8 citations
33. 33*

    From the Wavefunction of the Universe to In-In-Correlators: A Perturbative Map to All Orders

    Gonzalo A. Palma🇨🇱

    Both the Wavefunction of the Universe and the Schwinger-Keldysh in-in formalism are central tools for analyzing primordial cosmological observables, such as equal-time correlation functions. While their conceptual equivalence is well established, a systematic and explicit map between their diagrammatic expansions has remained elusive. In this article, I construct such a map by analyzing the relation between the two frameworks at the diagrammatic level. I show that diagrams contributing to correlation functions in the Wavefunction of the Universe approach can be uniquely reorganized into Schwinger-Keldysh diagrams. This correspondence holds to all orders in perturbation theory, including arbitrary numbers of interaction vertices and loops.

    ↳ hep-thastro-ph.COgr-qchep-phJHEP(2026)·2 citations
34. 34*

    A refined model of secondary photon emission from heavy WIMP annihilations in the Galactic Centre

    Rajat Shinde🇮🇳 · Julia Djuvsland🇩🇪 · Davide Dapaoli🇩🇪 · Jim Hinton🇩🇪

    Heavy Weakly Interacting Massive Particles (WIMPs) remain a prominent yet less constrained dark matter (DM) candidate, with the Galactic Centre (GC) serving as a prime target for indirect detection via gamma-ray signals. Extending our previous work that highlighted the significance of secondary inverse Compton (IC) emission from annihilation-produced electrons, we expand the analysis to a broader range of WIMP masses and introduce a more realistic spatially-dependent modelling framework for the GC environment. This approach incorporates complexities such as the three-dimensional DM distribution, spatially varying radiation and magnetic fields, and electron transport mechanisms like Galactic winds and diffusion. We assess the impact of these environmental factors on both the spatial and spectral characteristics of the resulting secondary emissions. Our results demonstrate the robustness and necessity of incorporating this emission, and highlight its role in enhancing the prospects for detecting heavy WIMPs through observations of the inner Galaxy. We provide the resulting data products to the community to support future analyses and observational studies.

    ↳ astro-ph.HEhep-phAstropart.Phys.(2026)·0 citations
35. 35*

    Comment on QED Corrections to the Parity Violating Asymmetry in High-Energy Electron-Nucleus Scattering

    Brendan T. Reed🇺🇸 · C. J. Horowitz🇺🇸

    In a recent letter Roca-Maza and Jakubassa-Amundsen claim a large $\approx 5\%$ radiative correction to the parity-violating asymmetry $A_{pv}$ in electron-nucleus scattering. If true, this would be important for the interpretation of the PREX, CREX, and MREX experiments. However, Roca-Maza and Jakubassa-Amundsen do not explicitly include the axial-vector vertex correction to $Z^0$ exchange (at the momentum transfer of the experiment). We show that including this cancels much of the change in $A_{pv}$.

    ↳ nucl-thhep-phnucl-ex5 citations
36. 36*

    Gaussian fluctuating Generally covariant diffusion

    David Montenegro🇧🇷 · Giorgio Torrieri🇧🇷

    We extend the previously developed [1] generally covariant formalism to include diffusion of conserved charges, and comment on the seming difference between the chemica potential term and the diffusion term

    ↳ hep-thgr-qchep-phnucl-thPRD(2026)·2 citations
37. 37*

    Exploring bound states and interactions of the nucleon-antinucleon system in a constituent quark model

    Aaron Park🇰🇷 · Sungtae Cho🇰🇷 · Su Houng Lee🇰🇷

    In this work, we study the nucleon-antinucleon system in a constituent quark model. We first construct the nucleon-antinucleon wave function such that the multiquark and multiantiquark components each satisfy the Pauli exclusion principle, and then investigate the possibility of a bound state using a Hamiltonian that includes color-color, spin-dependent interactions and three-quark potentials. Our results indicate that, in specific channels, the nucleon-antinucleon interaction exhibits significant attraction, suggesting a strong possibility of a bound state.

    ↳ nucl-thhep-ph0 citations
38. 38*

    Wilson-'t Hooft classification and the perimeter law for dyonic loops in 3d monopole semiclassics

    Yui Hayashi🇯🇵 · Yuya Tanizaki🇯🇵

    We investigate the long-distance behavior of dyonic loop operators in 4d $SU(N)$ gauge theories on ${\mathbb{R}}^3\times S^1$ using the 3d monopole semiclassics. If we employ the naive definition of the 't Hooft loop in the Abelianized regime, the dyonic loop operators do not admit the well-defined computations within the effective field theory. Moreover, if one forcibly proceeds with the computations of their expectation values, all the dyonic loops turn out to show the area law, which contradicts the prediction of the Wilson-'t Hooft classification. In this paper, we resolve this puzzle by employing the notion of screening for line operators, and we argue that the dyonic loops are screened by a defect known as the twist vortex, which is non-dynamical in the infrared effective theory but is dynamical in the original ultraviolet theory. The dyonic loops properly dressed by twist vortices admit the well-defined computations within the effective field theory, and we reproduce the kinematic prediction of the Wilson-'t~Hooft classification using the $3$d monopole semiclassics. Furthermore, we apply our framework to the thermal deconfined phase to evaluate the dual string tension, elucidating the topological nature of ${\mathbb{Z}}_N$ domain walls. We confirm that the domain-wall state has the phase transition at $\theta =\pi$ in the thermal deconfined phase despite the fact that the bulk state is smooth there.

    ↳ hep-thhep-lathep-phJHEP(2026)·1 citation
39. 39*

    Joint Constraints on Neutrinos and Dynamical Dark Energy in Minimally Modified Gravity

    Artur Ladeira🇧🇷 · Rafael C. Nunes🇧🇷 · Supriya Pan🇮🇳 · Weiqiang Yang🇨🇳

    The \(w_{\dagger}\)VCDM framework provides a theoretically well-controlled extension of \(\Lambda\)CDM within the class of minimally modified gravity theories, allowing for flexible cosmological background evolution and linear perturbation dynamics while remaining free of pathological instabilities. In this work, we have shown that this scenario remains robust when confronted with current cosmological observations, even in the presence of an extended neutrino sector. Combining \textit{Planck} CMB data with DESI DR2 BAO and DESY5 supernovae, we obtain stringent constraints on neutrino physics, including \(\sum m_\nu < 0.11~\mathrm{eV}\) (95\% CL) and \(N_{\rm eff} = 2.98^{+0.13}_{-0.14}\), fully consistent with Standard Model expectations. Crucially, the data exhibit a statistically significant preference for a late-time dark-energy transition, characterized by a robust quintessence--phantom crossing that remains stable across all dataset combinations and neutrino-sector extensions, including the presence of a sterile neutrino. The combined effects of modified late-time expansion and additional relativistic degrees of freedom systematically raise the inferred Hubble constant, substantially alleviating the \(H_0\) tension without invoking early dark energy or introducing theoretical instabilities. Overall, the \(w_{\dagger}\)VCDM scenario emerges as a compelling phenomenological framework that simultaneously accommodates current constraints on neutrino physics, provides an excellent fit to recent BAO and supernovae data, and offers a viable pathway toward resolving persistent tensions in the standard cosmological model.

    ↳ astro-ph.COgr-qchep-phPRD(2026)·15 citations
40. 40*

    Entanglement Viscosity: from Unitarity to Irreversibility in Accelerated Frames

    G. Yu. Prokhorov🇷🇺

    We demonstrate that the unitarity of quantum field theory, through the positivity of spectral functions, underlies thermodynamic irreversibility for a subsystem separated by a horizon, in direct analogy with the irreversibility of renormalization-group flows. To this end, we explicitly find the shear and bulk viscosities -- the entanglement viscosities -- for thermal radiation in Rindler space using the universal spectral representation. A direct consequence of the obtained general formulas is the relationship between the acceleration-induced shear viscosity in flat space and the conformal quantum anomaly in curved space, pointing to a possible novel probe of the conformal anomaly in systems with extreme acceleration. Moreover, for conformal field theories, we explicitly show that globally entanglement viscosity saturates the Kovtun-Son-Starinets bound.

    ↳ hep-thhep-phnucl-thPRD(2026)·4 citations
41. 41*

    More on Pre-Inflationary Non Gaussianities

    M. Meo🇮🇹

    I generalize the three-point amplitude of curvature perturbations in the climbing scenario inspired by ten-dimensional non-supersymmetric strings to a broader class of exponential potentials, under some assumptions on the smoothing effects of String Theory that favor a bounce Cosmology. The extension can encompass the SO(16)xSO(16) model, together with other scenarios related to supersymmetry breaking in String Theory. The e-fold ranges compatible with Planck data move toward lower values of N for milder potentials and toward larger values for steeper ones. I also compute the three-point amplitudes involving graviton modes in the same bounce scenario, showing in detail their lack of peculiar contributions from the turning point.

    ↳ hep-thgr-qchep-phEPJC(2026)·0 citations
42. 42*

    Resolution of the hyperfine puzzle and its significance for two fermion Dirac atoms

    Gordon Baym🇺🇸 · Glennys Farrar🇺🇸

    The hyperfine interaction in the ground state of a hydrogen atom of assumed radius $R$ is proportional to $-1/R^3$, raising the question of why the hyperfine interaction does not lead to collapse of hydrogen, or positronium. We approach the problem in terms of a minimax variational calculation based on the exact Gordon solution of the Dirac equation for the hydrogen atom ground state. The full Dirac treatment leads to the result that in an assumed variational state of size $R$, when $R$ minimizes the total energy the magnetic moment of the electron assumes its usual value, $e\hslash /2mc$, but when $R<\hslash /mc$, the effective electron magnetic moment becomes essentially $eR/2$, softening the hyperfine interaction and eliminating an energy minumum at small $R$. The magnetic moment of the proton is similarly suppressed, and the hyperfine interaction of a small size atom becomes bounded by the kinetic energy, thus assuring stability. We extend the Dirac variational calculation to positronium where we find simple results for the ground state energy and hyperfiine interaction, and then extend this variational calculation to Coulombic atoms of two fermions of arbitrary masses. This paper also lays out a framework for treating diquarks as relativistic Coulombic systems, in the presence of color electric and magnetic interactions.

    ↳ physics.atom-phhep-phnucl-thPRA(2026)·1 citation
43. 43*

    Axions explain the formation of supermassive black holes at cosmic dawn

    Pierre Sikivie🇺🇸 · Yuxin Zhao🇺🇸

    In a recent paper we pointed out that supermassive black holes, with masses ranging from $10^5$ to $10^{10}{M}_{\odot }$ form naturally at cosmic dawn if the dark matter is QCD axions or axion-like particles with mass $m>10^{-16}\mathrm{eV}/c^2$. No additional assumptions are required. Here we answer in detail the most commonly raised questions regarding our work.

    ↳ astro-ph.HEhep-phPoS(2026)·1 citation
44. 44*

    Quantum dynamics of cosmological particle production: interacting quantum field theories with matrix product states

    Evan Budd🇺🇸 · Adrien Florio🇩🇪 · David Frenklakh🇺🇸 · Swagato Mukherjee🇺🇸

    Understanding real-time dynamics of interacting quantum fields in curved spacetime remains a major theoretical challenge. We employ tensor network methods to study such dynamics using interacting scalar and gauge theories in 1+1 spacetime dimensions, subject to a quench modeling a homogeneously expanding gravitational background. The models considered are the scalar $\lambda {\varphi }^4$ theory and the Schwinger model, i.e. a Dirac fermion coupled to a $U(1)$ gauge field which is equivalent via bosonization to a scalar field with a cosine self-interaction. In the free scalar limit, both theories reproduce known analytical results, providing a nontrivial numerical validation of bosonization in curved spacetime for the Schwinger model. Our central finding is that self-interactions lead to a suppression of gravitational particle production compared to the free-field case, as evidenced by two-point functions and the spectra of produced particles. We further examine the behavior of entanglement generation and find that interactions suppress entanglement growth in the $\lambda {\varphi }^4$ theory, while in the Schwinger model, the interplay between suppressed particle production and enhanced inter-particle correlations leads to more complex entanglement behavior. Our results pave the way for further explorations of nonperturbative quantum real-time dynamics of interacting scalar and gauge theories in arbitrary gravitational backgrounds.

    ↳ hep-thastro-ph.COhep-lathep-phJHEP(2026)·4 citations
45. 45*

    Cosmic Collider Gravitational Waves sourced by Right-handed Neutrino production from Bubbles: Testing Seesaw, Leptogenesis and Dark Matter

    Anish Ghoshal🇵🇱 · Pratyay Pal🇮🇳

    We study a minimal type-I seesaw framework in which a first-order phase transition (FOPT), driven by a singlet scalar, produces right-handed neutrinos (RHNs) through bubble collisions, realizing a cosmic-scale collider that probes ultra-high energy scales. The resulting RHN distribution sources novel low-frequency gravitational-waves (GWs) in addition to the standard bubble-collision contribution. A stable lightest RHN can account for the observed dark matter (DM) relic abundance for masses as low as $M_1\equiv m_{\mathrm{DM}}\gtrsim 10^6\mathrm{GeV}$, with the associated novel GW signal accessible in LISA, ET and upcoming LVK detectors. If the RHNs are unstable, their CP-violating decays generate the observed baryon asymmetry via leptogenesis for $M_1\gtrsim 10^{11}\mathrm{GeV}$ and phase transition temperatures $T_{\ast }\gtrsim 10^6\mathrm{GeV}$, for which the novel GW spectrum is detectable in ET, BBO and upcoming LVK. If RHN decays also populate a dark-sector fermion with mass $m_{\chi }\in [10^{-4},10^4],\mathrm{GeV}$, successful co-genesis of baryons and asymmetric dark matter occurs for $T_{\ast }\gtrsim 10^7\mathrm{GeV}$ and $M_1\gtrsim 10^9\mathrm{GeV}$, naturally explaining ${\Omega }_{\mathrm{DM}}\simeq 5{\Omega }_{\mathrm{B}}$. The corresponding GW signals are testable with LISA, ET, and BBO. Finally, we analyze a UV-complete multi-Majoron model, based on a global $U(1{)}_N\times U(1{)}_{\mathrm{B}-\mathrm{L}}$ extension, motivated from the hierarchy of lepton masses, which we dub as Mojaron collider. The corresponding FOPT in this model leaves a distinctive GW signature arising from RHN production during $U(1{)}_N$ symmetry breaking detectable by BBO, ET and upcoming LVK. Successful leptogenesis is realized for heaviest RHN mass $M_3\sim 10^{10}\mathrm{GeV}$ and a $U(1{)}_N$ breaking vev $v_2\sim \mathcal{O}(\mathrm{TeV})$, which sets the seesaw scale.

    ↳ astro-ph.COgr-qchep-phhep-thPRD(2026)·7 citations
46. 46*

    Neutrino flavor instabilities in neutron star mergers with moment transport: Slow, fast, and collisional modes

    Julien Froustey🇪🇸 · Francois Foucart🇺🇸 · Christian Hall🇺🇸 · James P. Kneller🇺🇸 · Debraj Kundu🇺🇸 · Zidu Lin🇺🇸 · Gail C. McLaughlin🇺🇸 · Sherwood Richers🇺🇸

    Determining where, when, and how neutrino flavor oscillations must be included in large-scale simulations of hot and dense astrophysical environments is an enduring challenge that must be tackled to obtain accurate predictions. Using an angular moment-based linear stability analysis framework, we examine the different kinds of flavor instabilities that can take place in the context of the post-processing of a neutron star merger simulation, with a particular focus on the collisional flavor instability and a careful assessment of several commonly used approximations. First, neglecting anisotropies of the neutrino field, we investigate the extent to which commonly used monoenergetic growth rates reproduce the results obtained from a full multi-energy treatment. Contrary to the large discrepancies found in core-collapse supernova environments, we propose a simple combination of energy-averaged estimates that reproduces the multi-energy growth rates in our representative simulation snapshot. We then quantify the impact of additional physical effects, including nuclear many-body corrections, scattering opacities, and the inclusion of the vacuum term in the neutrino Hamiltonian. Finally, we include the neutrino distribution anisotropies, which allows us to explore, for the first time in a multi-energy setting, the interplay between collisional, fast, and slow modes in a moment-based neutron star merger simulation. We find that, despite a dominance of the fast instability in most of the simulation volume, certain regions exhibit only a collisional instability, while others, especially at large distances, exhibit a slow instability that is largely underestimated if anisotropic effects are neglected.

    ↳ astro-ph.HEhep-phPRD(2026)·8 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.