Tue·Feb 3, 2026Tuesday·February 3, 2026

1. 01*

   Interference effects in new physics searches

   Tania Robens🇭🇷

   Interference effects are an important consequence of a correct description in physics theories within and beyond the Standard Model (SM) of particle physics. However, many current theoretical descriptions as well as experimental searches neglect such effects, which can, among others, lead to an incorrect description of e.g. kinematical distributions, at least within the context of UV-complete models. In this review, I briefly discuss the current status and most common descriptions as well as existing studies of such effects, where I focus on models with extended scalar searches.

   hep-phMod.Phys.Lett.A(2026)·2 citations
2. 02*

   Wave-like amplification of near-threshold two-particle reactions: from muon-catalyzed fusion to $\Lambda \bar{\Lambda }$ production at $e^{-}{e}^{+}$ annihilation

   Vladimir S. Melezhik🇷🇺

   A simple model is proposed to explain the recently found wave-like enhancement of the $\Lambda \bar{\Lambda }$ pair production near the threshold at the $e^{-}{e}^{+}$ annihilation, which allows extracting model-independent scattering parameters and spectral information for the $\Lambda \bar{\Lambda }$ pair from the oscillatory nature of the measured cross section. In particular, it predicts a single bound state of $\Lambda \bar{\Lambda }$ with a binding energy of ${\epsilon }_{\Lambda \bar{\Lambda }}=(36\pm 5)$MeV. The model is a generalization of the formulas obtained in our earlier work [1] to explain the effect of wave-like amplification found in it near the threshold of fusion reactions screened by a muon or electron. The analysis allows us to conclude that the effect of wave-like amplification is an integral feature of any two-particle near-threshold reaction. In this regard, it seems promising to investigate, within the framework of our model, the oscillatory nature of the electromagnetic form factors of hyperons and nucleons extracted in experiments on $e^{-}{e}^{+}$ annihilation. A natural further development of the model could be its generalization to processes of producing various hadron pairs in $e^{-}{e}^{+}$ annihilation.

   hep-phquant-ph0 citations
3. 03*

   Interpretation of ${\rm Y}(11020)$ as an $S$-Wave $B_1\bar{B}$--$B_1{\bar{B}}^{\ast }$ Molecular State

   Qing Lu🇨🇳 · Cai Cheng🇨🇳 · Yin Huang🇨🇳

   Although heavy-quark symmetry predicts a $B_1\bar{B}$ molecular partner of the $D_1\bar{D}$ molecule, no such state has been observed. We propose that the experimentally observed ${\rm Y}(11020)$ may be a candidate for such a state, possibly containing a $B_1{\bar{B}}^{\ast }$ component. To test this, we interpret ${\rm Y}(11020)$ as an $S$-wave $B_1\bar{B}$--$B_1{\bar{B}}^{\ast }$ molecule and compute its strong decay widths using the compositeness condition and effective Lagrangians. The couplings to $B_1$ and ${\bar{B}}^{(\ast )}$ are extracted by fitting ${\rm Y}(11020)\to e^{+}{e}^{-}$ and ${\rm Y}(11020)\to {\chi }_{bJ}\pi \pi \pi$ data. Using these couplings, we evaluate partial widths into $B_{(s)}^{(\ast )}{\bar{B}}_{(s)}^{(\ast )}$, $\pi \pi {\rm Y}(nS)$, $\pi \pi h_b(nP)$, and $\pi \pi \pi {\chi }_{b1}$ via hadronic loops, as well as three-body $B^{\ast }\pi {\bar{B}}^{(\ast )}$ decays via tree diagrams. The results indicate that ${\rm Y}(11020)$ is predominantly a $B_1\bar{B}$ molecule, with its main decay channel being $B_s^{\ast }{\bar{B}}^{\ast }$. The $\pi \pi {\rm Y}(nS)$ and $\pi \pi h_b(nP)$ widths are only a few eV, whereas $\pi \pi \pi {\chi }_{b1}$ reaches 0.167~MeV and the unobserved $\pi \pi \pi {\chi }_{b0}$ could be 0.754~keV. These distinctive decay patterns provide clear experimental signatures of the molecular nature of ${\rm Y}(11020)$ and offer a test of heavy-quark symmetry.

   hep-phhep-exhep-thPRD(2026)·0 citations
4. 04*

   Inclusive beauty-charmed baryons decay ${\Xi }_{bcq}\to {\Xi }_{ccq}+X$

   Guo-He Yang🇨🇳

   We investigate the inclusive weak decay ${\Xi }_{bcq}\to {\Xi }_{ccq}+X$ ($q=u,d,s$) within the framework of the non-relativistic potential quark model. Treating the heavy diquarks ${\Phi }_{bc}$ and ${\Phi }_{cc}$ as compact color anti-triplet bound states, we calculate the transition form factors via the overlap integral of Schrödinger wave functions derived from the Cornell potential. The decay rates for four dominant channels-${\Phi }_{bc}\to {\Phi }_{cc}+\bar{c}s$, ${\Phi }_{bc}\to {\Phi }_{cc}+\bar{u}s$, ${\Phi }_{bc}\to {\Phi }_{cc}+e/\mu +\bar{\nu }$, and ${\Phi }_{bc}\to {\Phi }_{cc}+\tau +{\bar{\nu }}_{\tau }$-are computed, yielding a total inclusive decay width of $\Gamma ({\Xi }_{bcq}\to {\Xi }_{ccq}+X)\approx 4.1\times 10^{-13}$ GeV. We also evaluate the potential background from $B_c^{-}\to {\Xi }_{cc}+X$ decays, finding a rate of approximately $3.0\times 10^{-14}$ GeV, which is roughly one order of magnitude smaller than the signal process. Our results suggest that the inclusive decay ${\Xi }_{bc}\to {\Xi }_{cc}+X$ , followed by the well-established ${\Xi }_{cc}$ decay chains, provides a viable discovery channel for the doubly heavy baryon ${\Xi }_{bc}$ at the LHC.

   hep-ph1 citation
5. 05*

   Analysis of ATLAS pp elastic measurements at $\sqrt{s}$=13 TeV and comparison with TOTEM measurements

   E. Ferreira🇧🇷 · T. Kodama🇧🇷 · A. K. Kohara🇫🇷

   A comparative description is made of the measurements at LHC of pp elastic scattering at 13 TeV by the ATLAS and TOTEM Collaborations. In the total and differential cross sections we show that the differences are justified through single numerical factor. It seems that there is no fundamental physical difference, but only a difference of normalization between the two experiments. We study the real and imaginary amplitudes disentangled with the KFK (Kohara-Ferreira-Kodama) model and show that the properties are similar in qualitative aspects for both experiments. The real and imaginary parts have different slopes at the origin and present zeros, with distributions that are common to several models, with three zeros in the real part and one zero in the imaginary amplitude. A zero in the real part, known as Martin's zero, influences the determination of the $\rho$ parameter.

   hep-phEPJC(2026)·0 citations
6. 06*

   Inclusive electron-proton measurement prospects in the Electron-Ion Collider early science stage

   Javier Jiménez-López🇪🇸 · Stephen Maple🇬🇧 · Paul R. Newman🇬🇧 · Katarzyna Wichmann🇩🇪

   We explore the potential for extracting proton structure functions, proton parton density functions (PDFs), and the strong coupling ${\alpha }_s(M_z^2)$, using early science data from the future Electron-Ion Collider (EIC), both standalone, and in combination with HERA data. Different scenarios are considered in which samples with modest luminosity are collected at either two or three EIC beam energy configurations. The Rosenbluth separation method is used to extract the proton structure functions $F_2$ and $F_L$ from simulated data in a model-independent manner, showing that $F_L$ can be extracted significantly more precisely with three centre of mass energies than with two, whilst also obtaining $F_2$ to higher precision than has been achieved previously. The inclusion of a third beam configuration is also beneficial in the extraction of the strong coupling ${\alpha }_s(M_z^2)$ that is obtainable with unprecedented experimental precision with the early EIC data. Additionally, the precision of the proton PDFs is improved when adding these data, especially for large values of Bjorken-$x$, for both two and three EIC beam energy configurations. These studies show that EIC data will already be a highly competitive probe of perturbative Quantum Chromodynamics within the first five years of data taking.

   hep-phPRD(2026)·2 citations
7. 07*

   The Balitsky-Kovchegov equation for dipole gluon density in the momentum space

   Krzysztof Kutak🇵🇱

   I present derivation the BK equation for the dipole gluon density in momentum space, starting from its standard formulation in coordinate space. I review the equation for both proton and nuclear targets, and I also discuss the resummed BK evolution.The purpose of this paper is to consolidate derivations and formulas scattered across the literature, to show in detail how the structure of the triple-Pomeron vertex emerges in the unfolded form of the nonlinear term, and to establish a consistent notation throughout.

   hep-ph1 citation
8. 08*

   Vacuum polarization and pair production in time-dependent electric fields: A quantum-kinetic-equation approach

   I. A. Aleksandrov🇷🇺 · V. A. Bokhan🇷🇺 · A. I. Baksheev🇷🇺 · A. Kudlis🇮🇸

   The evolution of the vacuum state in a time-dependent external electric field of arbitrary polarization is investigated within a nonperturbative framework of quantum kinetic equations (QKEs). In our previous work [Phys. Rev. Res. 6, 043009 (2024)], a revised version of the QKEs was derived by using an adiabatic basis constructed from one-particle Hamiltonian eigenfunctions in a spatially homogeneous electric field. In this study, we present an extensive analysis of these equations with particular emphasis on observable quantities. Specifically, we compute momentum-resolved particle yields, the induced electron-positron current, the energy-momentum tensor, and the angular-momentum tensor. We also discuss in detail the charge-renormalization procedure required to remove logarithmic divergences. It is shown that our results are consistent with the previous findings obtained via the Dirac-Heisenberg-Wigner formalism. Our analysis provides a firmer theoretical basis for investigations of nonperturbative effects in strong electric fields.

   hep-phPRD(2026)·1 citation
9. 09*

   Search for Vector-Like Singlet Top ($T$) Quark in a Future Muon-Proton ($\mu p$) Collider at $\sqrt{s}=5.29,6.48,$ and $9.16$ TeV using Advanced Machine Learning Architectures

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

   In this work, we explore the discovery potential of Vector-Like Singlet Top quarks ($T$) at a future $\mu p$ collider with center-of-mass energies of 5.29, 6.48, and 9.16 TeV, providing a unique environment to probe beyond Standard Model limits. We analyze the $T\to Wb$ decay mode in both fully hadronic ($bjj$) and leptonic ($bl\nu$) final states, offering a multi-channel assessment of $T$-quark sensitivity across a mass range of 2 to 5 TeV. Our methodology employs multivariate classifiers such as Boosted Decision Trees (BDTs) and Multi-Layer Perceptrons (MLP) to optimize signal-to-background discrimination in complex final states. The results demonstrate that the 9.16 TeV benchmark acts as a definitive discovery machine; even with 100 fb${}^{-1}$ of data, the statistical significance exceeds $5\sigma$ up to 4 TeV masses. We identify a crossover effect where hadronic channels provide superior reach at intermediate masses due to higher branching ratios, while leptonic channels offer robustness at 5 TeV where purity limits detection. Incorporating a 20\% systematic uncertainty via Asimov significance ($Z_A$), we quantify the transition from fluctuation-dominated to systematic-dominated regimes at high luminosities. At 3000 fb${}^{-1}$, regions with $g^{\ast }\in [0.20,0.50]$ and $m_T$ up to 4 TeV are discoverable via the hadronic channel with MLP, and regions with $g^{\ast }\in [0.10,0.50]$ and $m_T$ up to 5 TeV are accessible through the leptonic channel with BDT, highlighting the collider's potential to probe new physics beyond the Standard Model.

   hep-ph1 citation
10. 10*

    Insights into the exotic charged states $Z_b(10610)$ and $Z_b(10650)$ from their photoproduction off nuclei

    E. Ya. Paryev🇷🇺

    The possibility to study the nature of the famous charged bottomonium-like states $Z_b(10610)$ and $Z_b(10650)$, which is by far the best known, from their inclusive photoproduction off nuclei near the kinematic threshold is investigated within the collision model based on the nuclear spectral function. The model accounts for $Z_b(10610{)}^{\pm }$ and $Z_b(10650{)}^{\pm }$ production in direct photon--nucleon interactions as well as four different scenarios for their intrinsic configurations: compact tetraquarks, molecules of the two open-beauty mesons and two mixtures of both of them for each of $Z_b$ state. We calculate within these scenarios the absolute and relative excitation functions on ${}^{12}$C and ${}^{184}$W nuclei at photon energies of 61--90 GeV, the absolute momentum differential cross sections and ratios of them for their production off these target nuclei at laboratory polar angles of 0${}^{\circ }$--5${}^{\circ }$ and for photon energy of 75 GeV as well as the A-dependences of the transparency ratios for the $Z_b(10610{)}^{\pm }$ mesons at photon energy of 75 GeV. We show that the absolute and relative observables considered reveal distinct sensitivity to the $Z_b(10610{)}^{\pm }$ and $Z_b(10650{)}^{\pm }$ internal structures. Therefore, they might be useful for the determination of these structures from the comparison of them with the experimental data from the future high-precision experiments at the upcoming experimental facilities, such as the planned high-luminosity electron-ion colliders in the United States and China.

    hep-phhep-exnucl-exNPA(2026)·0 citations
11. 11*

    Fragmentation functions for gluon into $P$-wave $B_c$ mesons

    Xu-Chang Zheng🇨🇳 · Xing-Gang Wu🇨🇳

    We calculate the fragmentation functions for a gluon into $P$-wave $B_c$ mesons within the nonrelativistic QCD factorization framework, incorporating color-singlet and color-octet contributions. Ultraviolet divergences arising from phase-space integrals are removed via operator renormalization in the modified minimal subtraction scheme. The resulting fragmentation functions are presented in both graphical form and as fitted analytic expressions.

    hep-ph1 citation
12. 12*

    Constraints on birefringence-free photon theory within standard-model extension

    Zhi Xiao🇨🇳 · Hanlin Song🇨🇳 · Bo-Qiang Ma🇨🇳

    Constraints on the birefringence-free subset of Lorentz-violating (LV) operators are derived using 14 GRB photons in the GeV-band. These constraints target the isotropic $c_{(I)00}^{(d)}$ coefficients for dimensions $d=6,8,10$ within the framework of the Standard-Model Extension (SME). Employing theory-agnostic Bayesian parameter estimation methods, our analysis indicates a preference for subluminal LV effects. Focusing on this case, we further refine the parameter constraints, yielding results that are mutually consistent. Within the 95\% posterior credible interval, our constraints yield the bounds, $|c_{(I)00}^{(6)}|\le 7.75\times 10^{-20}{\mathrm{GeV}}^{-2}$, $|c_{(I)00}^{(8)}|\le 4.92\times 10^{-24}{\mathrm{GeV}}^{-4}$, and $|c_{(I)00}^{(10)}|\le 3.46\times 10^{-28}{\mathrm{GeV}}^{-6}$, which improve upon the most stringent credible-interval bounds reported in the literature by at least five orders of magnitude.

    hep-phPRD(2026)·0 citations
13. 13*

    Two-loop renormalisation of the quark fields in the presence of four-fermion SMEFT operators

    Claude Duhr🇩🇪 · Giuseppe Ventura🇬🇧 · Eleni Vryonidou🇬🇧

    We compute the contributions of the dimension-6 SMEFT operators involving four third-generation quarks to the two-loop renormalisation of the quark fields and masses. We perform the computations in both the Naive Dimensional Regularisation (NDR) and the Breitenlohner-Maison-`t Hooft-Veltman (BMHV) schemes, and we present results for all relevant field and mass renormalisation constants in the on-shell and MS-bar schemes. We carefully discuss all scheme choices which affect the final results. This completes the computation of field and mass renormalisation constants relevant for two-loop computations in QCD involving dimension-six SMEFT operators.

    hep-phJHEP(2026)·2 citations
14. 14*

    An introduction to gauge theories and group theory in particle physics

    Hao-Lin Li🇨🇳 · Hao Sun🇨🇳 · Ming-Lei Xiao🇨🇳 · Jiang-Hao Yu🇨🇳

    In this review, the fundamental concepts of group theory and representation theory are introduced. Special emphasis is placed on the unitary irreducible representations of the $SU(N)$ Lie group, the Poincare group, Little Group, discrete group, and their applications in particle physics. Based on the principle of local gauge symmetry, the construction of gauge-invariant Lagrangians and their quantization procedure are discussed. To address gauge redundancy, the modern on-shell amplitude approach is applied to gauge theories, demonstrating both conceptual and computational advantages. From the perspective of symmetry, the Standard Model is presented through the identification of its gauge symmetry, its anomaly-free matter content, and its global symmetries, including flavor symmetry, custodial symmetry, and baryon and lepton number conservation, etc.

    hep-ph0 citations
15. 15*

    CP violation in H^\pm \to W^\pm Z: A physical approach for the 2HDM

    Wafaa Khater🇵🇸 · Odd Magne Ogreid🇳🇴 · Per Osland🇳🇴 · Margarida Nesbitt Rebelo🇵🇹

    We investigate CP violation in the process H^\pm \to W^\pm Z within the framework of the two-Higgs-Doublet model (2HDM). Amplitudes are expressed transparently in terms of physical couplings. Our analysis qualitatively confirms recent results by Kanemura and Mura, for the interference between one-loop bosonic and fermionic amplitudes. Furthermore, we identify additional sources of CP violation arising from internal interference among the bosonic and also among the fermionic loop amplitudes. In the alignment limit, the asymmetry would vanish in the absence of fermionic loop contributions when the sum of the masses of the additional neutral scalars is higher than the mass of the Z. Our results allow for generic Yukawa couplings, and cover both explicit and spontaneous CP violation. For inclusive W^\pm and Z decays, the CP violation will only manifest itself as a charge asymmetry.

    hep-phJHEP(2026)·0 citations
16. 16*

    The simplest Exotic Invariant (E3)

    John A. Dixon🇨🇦

    This paper E3 shows how to construct the simplest Exotic Invariant in the simplest way.

    hep-ph2 citations
17. 17*

    HDSense: An efficient method for ranking observable sensitivity

    Benoît Assi🇺🇸 · Christian Bierlich🇸🇪 · Rikab Gambhir🇺🇸 · Phil Ilten🇺🇸 · Tony Menzo🇺🇸 · Stephen Mrenna🇺🇸 · Manuel Szewc🇺🇸 · Michael K. Wilkinson🇺🇸 · Jure Zupan🇺🇸

    Identifying which observables most effectively constrain model parameters can be computationally prohibitive when considering full likelihoods of many correlated observables. This is especially important for, e.g., hadronization models, where high precision is required to interpret the results of collider experiments. We introduce the High-Dimensional Sensitivity (HDSense) score, a computationally efficient metric for ranking observable sets using only one-dimensional histograms. Derived by profiling over unknown correlations in the Fisher information framework, the score balances total information content against redundancy between observables. We apply HDSense to rank a set observables in terms of their constraining power with respect to five parameters of the Lund string model of hadronization implemented in Pythia using simulated leptonic collider events at the $Z$ pole. Validation against machine-learning--based full-likelihood approximations demonstrates that HDSense successfully identifies near-optimal observable subsets. The framework naturally handles data from multiple experiments with different acceptances and incorporates detector effects. While demonstrated on hadronization models, the methodology applies broadly to generic parameter estimation problems where correlations are unknown or difficult to model.

    hep-phhep-exstat.ME1 citation
18. 18*

    Contributions of the subprocesses $\rho (770,1450,1700)\to K\bar{K}$ and $\omega (782,1420,1650)\to K\bar{K}$ for the three-body decays $B\to {\eta }^{(\prime )}K\bar{K}$

    Ming-Yue Jia🇨🇳 · Jia-Xin Wang🇨🇳 · Li-Fei Yang🇨🇳 · Ai-Jun Ma🇨🇳 · Wen-Fei Wang🇨🇳

    As an extension of our prior work, we analyze the resonance contributions for the kaon pair originating from the intermediate $\rho (770)$, $\omega (782)$ and their excited states in the three-body decays $B\to {\eta }^{(\prime )}K\bar{K}$ within the perturbative QCD approach. The information of subprocesses $\rho (770,1450,1700)\to K\bar{K}$ and $\omega (782,1420,1650)\to K\bar{K}$ are included in the distribution amplitudes for $K\bar{K}$ system by using the kaon vector time-like form factors. We calculate the $CP$ averaged branching fractions and the direct $CP$ asymmetries for the relevant quasi-two-body $B$ meson decays. The branching fractions of the virtual contributions for $K\bar{K}$ from the Breit-Wigner formula tails of $\rho (770)$ and $\omega (782)$ for these decays are found comparable to the corresponding contributions from the resonances $\rho (1450,1700)$ and $\omega (1420,1650)$. Consequently, they constitute a significant component that should be accounted for in the considered three-body decays. All the predictions in this work are expected to be tested by the LHCb and Belle-II experiments in the future.

    hep-phhep-exCPC(2026)·0 citations
19. 19*

    Impact of Colliding Beams Helicity on the Production of Leptoquarks and Collider Experimental Parameters

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

    Vector Leptoquarks (VLQs) have emerged as primary candidates for resolving discrepancies in the Standard Model, specifically within $B$-meson decay channels and the anomalous magnetic moment of the muon. This work presents a rigorous evaluation of VLQ pair production across $e^{-}{e}^{+}$ collision modes at future linear colliders with center-of-mass energies ranging from 14~TeV to 100~TeV. Our analysis demonstrates that longitudinal beam polarization is a transformative tool for enhancing signal sensitivity. We find that $e^{-}{e}^{+}$ annihilation consistently yields superior cross-sections compared to photon fusion processes across a mass range of 500--3000~GeV. By optimizing beam helicity to specific configurations, such as $P_{e^{-}}=-0.8$ and $P_{e^{+}}=+0.6$, the production cross-section can be maximized to 120~fb at $\sqrt{s}=3$~TeV. We further establish that the Left-Right Asymmetry ($A_{LR}$) serves as a robust discriminator for the chiral structure of new physics, peaking at 0.16 under full polarization. Additionally, we show that effective luminosity can be enhanced to 95\% of the total luminosity, while high polarization degrees significantly suppress relative uncertainties in the effective polarization. These results provide a quantitative roadmap for optimizing discovery potential and minimizing systematic errors in future high-energy physics experiments.

    hep-ph0 citations
20. 20*

    Fully strange tetra- and penta-quarks in a chiral quark model

    Gang Yang🇨🇳 · Jialun Ping🇨🇳 · Jorge Segovia🇪🇸

    Motivated by the recently reported resonant structure $X(2300)$, a strong candidate for a fully strange tetraquark with positive parity, we perform a systematic study of fully strange tetra- and penta-quark systems within a chiral quark model. Low-lying $S$-wave configurations of the $ss\bar{s}\bar{s}$ and $ssss\bar{s}$ systems are investigated using the Gaussian Expansion Method (GEM) combined with the Complex Scaling Method (CSM), which allows for a unified treatment of bound, resonant, and scattering states. For tetraquarks, all possible configurations: meson-meson, diquark-antidiquark, and K-type structures, with complete color bases, are incorporated, while baryon-meson and diquark-diquark-antiquark configurations are considered for pentaquarks. Several weakly bound states and narrow resonances are identified in both sectors. In particular, a compact fully strange tetraquark with $J^P=1^{+}$ is found near $2.3\text{GeV}$, providing a natural interpretation of the $X(2300)$ resonance. Additional exotic states with dominant hidden-color and K-type components are predicted in the mass ranges $1.6-3.1$ GeV for tetraquarks and $2.6-3.2$ GeV for pentaquarks. The internal structure of these states is analyzed through their sizes, magnetic moments, and wave-function compositions, highlighting the essential role of channel coupling and exotic color configurations. Finally, promising two-body strong decay channels are proposed to facilitate future experimental searches.

    hep-phhep-exhep-latnucl-ex+1PRD(2026)·0 citations
21. 21*

    Production of $\varphi \Lambda$, $D_s^{\ast -}{\Lambda }_c^{+}$, and $J/\psi \Lambda$ in kaon-induced reactions off the nucleon

    Sang-Ho Kim🇰🇷

    We investigate the reaction mechanism of strangeness production in $K^{-}p\to \varphi \Lambda$ within a hybrid Regge approach, taking into account $t$-channel $K$- and $K^{\ast }$-Reggeon exchanges. We present results for the total cross section, $t$-dependent differential cross sections, and spin-density matrix elements (SDMEs), and compare them with the available experimental data. We find that $K^{\ast }$-Reggeon exchange provides the dominant contribution, while $K$-Reggeon exchange remains nonnegligible, particularly in describing the SDMEs. In contrast, the $s$-channel $\Lambda$ and $u$-channel nucleon exchanges are negligible. To obtain reliable predictions for the open-charm reaction $K^{-}p\to D_s^{\ast -}{\Lambda }_c^{+}$, we employ a Quark-Gluon String Model (QGSM)-motivated Regge framework that incorporates both pseudoscalar- and vector-Reggeon exchanges. Within this framework, the Regge trajectories $\alpha (t)$ and energy-scale parameters $s_0$ are determined consistently, thereby constaining the model and reducing theoretical ambiguities. For the hidden-charm reaction $K^{-}p\to J/\psi \Lambda$, we use the same quark-level diagrammatic correspondence. The total cross sections for $K^{-}p\to D_s^{\ast -}{\Lambda }_c^{+}$ and $K^{-}p\to J/\psi \Lambda$ are suppressed by approximately 5-6 and 8-9 orders of magnitude, respectively, compared with that for $K^{-}p\to \varphi \Lambda$. We also examine possible $s$-channel contributions from the hidden-charm pentaquark states with strangeness, $P_{cs}(4337{)}^0$ and $P_{cs}(4459{)}^0$, to both $D_s^{\ast -}{\Lambda }_c^{+}$ and $J/\psi \Lambda$ production.

    hep-phPRD(2026)·2 citations
22. 22*

    Disappearing Track Signals from a Light Charged Higgs in the Alternative Left-Right Model

    Hrishikesh Deka🇮🇳 · Avnish🇮🇳 · Poulose Poulose🇮🇳

    We study the phenomenology of a light charged Higgs boson in the framework of the Alternative Left--Right Symmetric Model (ALRM). In this model, stringent flavor constraints are evaded due to a non-conventional fermion spectrum in which the right-handed up-type quarks are paired with the exotic down-type quarks rather than the Standard Model down-type quarks, leading to the absence of tree-level flavor-changing neutral currents. Furthermore, a specific assignment of the global $U(1{)}_S$ symmetry and the resulting emergent $R$-parity prevent mixing between the right- and left-handed charged gauge bosons, $W_R$ and $W_L$, providing additional suppression of flavor-violating effects. The ALRM accommodates potentially viable dark matter candidates, both fermionic and scalar ones. In this context, an associated charged Higgs state, $H_2^{\pm }$, belonging to the dark sector can naturally acquire a sub-TeV to TeV-scale mass without conflicting with any experimental constraints. We focus on scenarios in which $H_2^{\pm }$ behaves as a long-lived particle due to a sub-GeV mass splitting with the dark matter candidate. We identify regions of parameter space consistent with the observed dark matter relic density and other experimental constraints. A detailed analysis of disappearing track signatures is performed, including realistic tracklet reconstruction efficiencies, and the existing ATLAS search are recast to assess the current limits and future sensitivities. We find that the HL-LHC has limited sensitivity to TeV-scale charged Higgs bosons in this scenario, while the 27 TeV HE-LHC can effectively probe the relevant parameter space, with a 100 TeV collider offering substantially enhanced discovery potential.

    hep-ph1 citation
23. 23*

    Systematical decomposition of dimension-11 short-range neutrinoless double beta decay operators

    Shi-Yu Li🇨🇳 · Gui-Jun Ding🇨🇳

    Neutrinoless double beta decay ($0\nu \beta \beta$) may receive sizable contributions from short-range physics beyond the Standard Model. We present a systematical classification of all tree-level ultraviolet completions of the dimension-11 short-range $0\nu \beta \beta$ decay operators, renormalizable scenarios with scalar and fermion mediators are considered. We identify eight distinct topologies and twenty-eight viable diagrams, from which all consistent UV completions are generated by imposing Standard Model gauge invariance. All these models involve a total of 61 new fields beyond the Standard Model and they typically feature fractionally charged fermions and exotic bosons such as dileptons, diquarks, and leptoquarks. We further study a representative model without colored mediators and analyze its implications for the $0\nu \beta \beta$ decay half-life and light neutrino masses. We find that current and future $0\nu \beta \beta$ decay experiments impose stringent constraints. Our systematic decomposition provides a general framework for exploring exotic short-range contributions to $0\nu \beta \beta$ decay in future experiments.

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

    Shallow $T_{bc}$ states from an EFT analysis of $B^{(\ast )}{\bar{D}}^{(\ast )}$ scattering on the lattice

    Michael Abolnikov🇩🇪 · Lu Meng🇩🇪 · Vadim Baru🇩🇪 · Evgeny Epelbaum🇩🇪 · Arseniy A. Filin🇩🇪 · Ashot M. Gasparyan🇩🇪

    We present an effective field theory (EFT) framework for coupled-channel $B^{(\ast )}{\bar{D}}^{(\ast )}$ scattering, applying it to recent lattice QCD results by Alexandrou et al. [Phys. Rev. Lett. 132, 151902 (2024)]. Two complementary EFT approaches are developed: (1) A low-energy theory near the $B\bar{D}$ ($J=0$) and $B^{\ast }\bar{D}$ ($J=1$) thresholds, where coupled-channel effects are integrated out; (2) A coupled-channel formulation, where all relevant momentum scales are treated as soft, incorporating contact interactions and one-pion exchange (OPE). Importantly, OPE contributes to the lowest channels only through off-diagonal transitions, thus resulting in the appearance of the left-hand cut from two-pion exchange. The two approaches yield mutually consistent results, supporting the existence of shallow bound states in both channels, in agreement with the lattice findings. The finite-volume spectra and extracted pole positions show a near-degeneracy in $J=0$ and $J=1$ channels, consistent with heavy-quark spin symmetry (HQSS). Using HQSS, we predict additional shallow bound states near the $B{\bar{D}}^{\ast }$ and $B^{\ast }{\bar{D}}^{\ast }$ thresholds, which are accessible to future lattice simulations. The effect of OPE on the finite volume spectra is found to be small, with only moderate impact on HQSS partners.

    hep-phhep-lathep-thPRD(2026)·1 citation
25. 25*

    A Novel Implementation of the Matrix Element Method at Next-to-Leading Order for the Measurement of the Higgs Self-Coupling ${\lambda }_{3H}$

    Matthias Tartarin🇫🇷 · Jan Stark🇫🇷

    The determination of the Higgs boson trilinear self-coupling ${\lambda }_{3H}$ is a key goal of the LHC physics programme. Its precise measurement will provide unique insight into the scalar potential and the mechanism of electroweak symmetry breaking. Higgs boson pair production in the $gg\to HH$ process, and particularly in the $HH\to b\bar{b}\gamma \gamma$ final state, offers direct sensitivity to ${\lambda }_{3H}$. We present the first implementation of the Matrix Element Method at Next-to-Leading Order (MEM@NLO) for this process, which is publicly available. The MEM is a statistically optimal approach that maximises information extraction from collision events. Extending it to NLO represents a major methodological challenge, which we address with a new formalism integrated into the MoMEMta framework. Results with simulated pseudo-experiments demonstrate, in a proof-of-principle study, the strong discriminating power of the method and its ability to extract the coupling modifier ${\kappa }_{\lambda }$=${\lambda }_{3H}$/${\lambda }_{3H}^{SM}$ with high precision.

    hep-phPRD(2026)·2 citations
26. 26*

    Chasing Long-Lived Doubly Charged Scalars at Future Lepton Colliders

    Nandini Das🇮🇳 · Dilip Kumar Ghosh🇮🇳 · Nivedita Ghosh🇯🇵 · Ritesh K. Singh🇮🇳

    We come up with a novel search strategy for long-lived doubly charged scalars at future proposed lepton colliders. The doubly charged scalar studied in this work belongs to an $SU(2{)}_L$ complex scalar triplet that accounts for tiny neutrino masses via the Type-II Seesaw mechanism. For scalar masses $\lesssim 200$ GeV and appropriate values of the triplet vacuum expectation value, this state can be long-lived and decay predominantly into like-sign muon pairs (e.g. ${\mu }^{+}{\mu }^{+}$ or ${\mu }^{-}{\mu }^{-}$), producing distinctive displaced-vertex signals. We investigate the pair production of these scalars at the International Linear Collider (ILC) and a prospective muon collider, considering their planned center-of-mass energies. Incorporating theoretical and experimental constraints, we study the resulting signature of four leptons accompanied by missing transverse energy. Displaced vertices offer direct evidence of the scalar's long lifetime, while we further show that the invariant mass distribution of same-sign dilepton pairs serves as a powerful complementary probe for discovering doubly charged Higgs bosons at both the ILC and muon collider.

    hep-ph1 citation
27. 27*

    Artificial Intelligence and Symmetries: Learning, Encoding, and Discovering Structure in Physical Data

    Veronica Sanz🇪🇸

    Symmetries play a central role in physics, organizing dynamics, constraining interactions, and determining the effective number of physical degrees of freedom. In parallel, modern artificial intelligence methods have demonstrated a remarkable ability to extract low-dimensional structure from high-dimensional data through representation learning. This review examines the interplay between these two perspectives, focusing on the extent to which symmetry-induced constraints can be identified, encoded, or diagnosed using machine learning techniques. Rather than emphasizing architectures that enforce known symmetries by construction, we concentrate on data-driven approaches and latent representation learning, with particular attention to variational autoencoders. We discuss how symmetries and conservation laws reduce the intrinsic dimensionality of physical datasets, and how this reduction may manifest itself through self-organization of latent spaces in generative models trained to balance reconstruction and compression. We review recent results, including case studies from simple geometric systems and particle physics processes, and analyze the theoretical and practical limitations of inferring symmetry structure without explicit inductive bias.

    hep-phcs.AIcs.LGInt.J.Mod.Phys.A(2026)·0 citations
28. 28*

    Pseudo-Goldstone Neutrinos and Majoron Phenomenology from Spontaneous $U(1)L\mu -L_{\tau }$ Breaking

    Gayatri Ghosh🇮🇳

    We present a predictive framework for neutrino mass generation based on the spontaneous breaking of a leptonic $U(1{)}_{L_{\mu }-L_{\tau }}$ symmetry within a supersymmetric setting. The breaking of the global symmetry gives rise to a Majoron-like axion-like particle and a pseudo-Goldstone right-handed neutrino whose mass is naturally suppressed by supersymmetry-breaking effects. The interplay between the pseudo-Goldstone neutrino and the low-scale seesaw mechanism leads to a structured neutrino mass matrix capable of reproducing the observed neutrino masses, mixing angles, and CP-violating phase without invoking extreme parameter hierarchies. We perform a numerical fit to current neutrino oscillation data and identify representative benchmark solutions consistent with laboratory constraints as well as cosmological and astrophysical bounds. A characteristic outcome of the framework is the emergence of correlated relations linking the symmetry breaking scale, heavy neutrino masses, Majoron couplings, and neutrino lifetimes. Majoron-induced invisible neutrino decay arises generically and can significantly modify cosmological neutrino mass constraints for sufficiently low symmetry breaking scales. We discuss the phenomenological implications across neutrino oscillation experiments, cosmology, and collider searches for long-lived heavy neutrinos. While a detailed experimental simulation is beyond the scope of this work, existing sensitivity projections indicate that portions of the parameter space may become accessible in future facilities. The combined interplay of laboratory probes and cosmological observations provides a consistent and testable picture of neutrino mass generation tied to spontaneous leptonic symmetry breaking and axion-like physics.

    hep-ph0 citations
29. 29*

    Study of Form Factors and Observables in $B_c^{-}\to D_s^{\ast -}{\ell }^{+}{\ell }^{-}$ and $B_c^{-}\to D_s^{\ast -}\nu \bar{\nu }$ decays

    Utsab Dey🇮🇳 · Soumitra Nandi🇮🇳

    We investigate the decays $B_c^{-}\to D_s^{(\ast )-}{\ell }^{+}{\ell }^{-}$ and $B_c^{-}\to D_s^{(\ast )-}\nu \bar{\nu }$ within the Standard Model (SM), employing perturbative QCD form factors that are sensitive to the wave functions of $B_c$ and $D_s^{(\ast )}$ mesons. We determine the shape parameters of these mesons and the $B_c\to D_s^{(\ast )}$ form factors at $q^2=0$ from available lattice QCD inputs for $B_s\to D_s^{(\ast )}$ and $B_c\to D_s$ transitions. To obtain the $q^2$ dependence of the $B_c\to D_s^{\ast }$ form factors, we employ heavy-quark spin symmetry and an appropriate parametrisation scheme over the allowed $q^2$ region. Based on these inputs, we present predictions for branching ratios and lepton-flavour-sensitive observables. Furthermore, we perform a detailed angular analysis of the cascade decay $B_c^{-}\to D_s^{\ast -}(\to D_s^{-}{\pi }^0){\ell }^{+}{\ell }^{-}$, providing Standard Model predictions for several angular observables.

    hep-ph0 citations
30. 30*

    NeutrinoOsc3Flavor: CP Phase Dependence in Three-Flavor Neutrino Oscillations: A Numerical Study in Vacuum and Matter

    Baktiar Wasir Farooq🇮🇳 · Bipin Singh Koranga🇮🇳 · Ansh Prasad🇮🇳 · Imran Khan🇮🇳

    We present NeutrinoOsc3Flavor, a lightweight and fully transparent computational framework for exact three flavor neutrino oscillation studies in vacuum and constant density matter. The code numerically solves the Schrodinger evolution equation in the flavor basis using explicit construction and diagonalization of the effective Hamiltonian within the PMNS formalism, including full CP Violating phase dependence. In contrast to large scale oscillation toolkits optimized for experimental simulations, NeutrinoOsc3Flavor is designed as a minimal dependency reference implementation, emphasizing analytical traceability, equation level accessibility, and cross platform portability. The framework relies solely on NumPy for numerical linear algebra and runs natively on both Linux and Windows systems without external compilation or specialized libraries. As an internal consistency and validation feature, we implement an independent analytical determination of the matter modified Hamiltonian eigenvalues using the Cardano method and demonstrate excellent agreement with numerical diagonalization. CP Phase dependence is used as a sensitive diagnostic of numerical stability and correctness of the evolution operator in both vacuum and matter. NeutrinoOsc3Flavor is intended as a verification oriented and pedagogical computational tool, suitable for theoretical cross-checks, educational use, and benchmarking of more complex neutrino oscillation software, rather than as a replacement for full experimental simulation frameworks. Here, we consider the DUNE experiments baseline length in the python implementation but in general we can implement any value of baseline length.

    hep-ph0 citations
31. 31*

    The ubiquitous flavor pendulum

    Damiano F. G. Fiorillo🇩🇪 · Georg G. Raffelt🇩🇪

    A system of classical interacting spins can develop collective instabilities which, in the nonlinear regime, mimic the motion of a gyroscopic pendulum. Known as the flavor pendulum, this behavior appears among the collective modes of a dense neutrino plasma after a strong reduction of phase space through symmetry assumptions. It has been identified in homogeneous slow and fast flavor systems and, most recently, in single-wave solutions of the fast system. We explain the reasons for its ubiquitous appearance. We show that a system of three classical spins must always be pendular, or only two in the presence of an external field. Furthermore, such a system always defines a continuum of vectors with time-independent length. If these are identified as interacting spins, they immediately lead to the continuum cases of slow and fast flavor pendula. As another new insight, any of these spins can be chosen as the pendulum, periodically exchanging flavor with the rest of the system.

    hep-phastro-ph.HEPRD(2026)·4 citations
32. 32*

    Axion-Like Electrophilic Portal for Pion Dark Matter

    Vincenzo Fiorentino🇮🇹 · Ji-Heng Guo🇨🇳 · Giacomo Landini🇮🇹 · Federico Mescia🇮🇹

    We investigate a scenario where Strongly Interacting Massive Particle (SIMP) dark matter interacts with an axion-like particle (ALP) that couples exclusively to electrons. This minimal setup provides interactions which enforce thermal equilibrium between dark matter and the SM in the early Universe. We analyze the cosmological evolution of the dark sector and the constraints arising from dark matter annihilations, ALP laboratory searches and astrophysical observations. Our results show that the allowed parameter space is wider than previous studies and an ALP with mass $m_a\sim \mathcal{O}(10)\text{MeV}$ can act as a viable portal between the visible and dark sectors. Interestingly, this mass range overlaps with the parameter space suggested by the reported $X_{17}$ anomaly. Furthermore, the introduction of non-vanishing $\theta$ angle in the dark sector of the model opens up the parameter space to heavy ALP masses.

    hep-phPRD(2026)·2 citations
33. 33*

    Realization of quintom dark energy after DESI DR2 in Nieh-Yan modified teleparallel gravity

    Yuxuan Kang🇨🇳 · Mingzhe Li🇨🇳 · Changzhi Yi🇨🇳

    Recent observations from the DESI Collaboration indicate a preference for quintom dark energy, i.e., its equation of state evolves across the cosmological constant boundary $w=-1$. It is well known that models with single perfect fluid or single scalar field minimally coupled to Einstein gravity develop perturbative instabilities around the crossing, thereby cannot realize the quintom scenario. In this paper, we propose a method to circumvent the instability problem of these models by considering the coupling of dark energy to the Nieh-Yan density within the framework of teleparallel gravity. We show that with this coupling the background evolution is not affected, but the dark energy perturbation is removed from the menu of dynamical degrees of freedom, thus avoiding the inherent difficulties in the old models. Furthermore, the Nieh-Yan coupling causes parity violation in gravitational waves, and this can be considered as a clear prediction of this mechanism.

    ↳ gr-qcastro-ph.COhep-phhep-thEPJC(2026)·2 citations
34. 34*

    Model Study of Eigen-Microstate Signatures of Criticality in Relativistic Heavy-Ion Collisions

    Ranran Guo🇨🇳 · Jin Wu🇨🇳 · Mingmei Xu🇨🇳 · Zhiming Li🇨🇳 · Zhengning Yin🇨🇳 · Yufu Lin🇨🇳 · Lizhu Chen🇨🇳 · Yanhua Zhang🇨🇳 · Jinghua Fu🇨🇳 · Xiaosong Chen🇨🇳 · Yuanfang Wu🇨🇳

    We present a comprehensive model study of the eigen-microstate approach (EMA) for identifying critical fluctuations in relativistic heavy-ion collisions. Using UrQMD and two stochastic baseline models, we demonstrate that EMA is insensitive to conventional short-range correlations and effectively filters out non-critical backgrounds. Critical fluctuations embedded via event-level or particle-level replacement with CMC events generate characteristic cluster-like eigen-microstate patterns and enhanced leading eigenvalues, with event-level criticality producing stronger responses. The eigen microstates exhibit the same pattern across different scales, demonstrating that the fractal nature of critical fluctuations is captured by the eigen microstates. Finite-size scaling of eigenvalue ratios exhibits fixed-point behavior, confirming the largest eigenvalue as an effective order-parameter-like quantity. These results demonstrate that EMA offers a robust and background-independent method for critical-point searches in the RHIC Beam Energy Scan and future heavy-ion experiments.

    ↳ nucl-thhep-ph1 citation
35. 35*

    Spin alignment, tensor polarizabilities, and local equilibrium for spin-1 particles

    Wojciech Florkowski🇵🇱 · Sudip Kumar Kar🇵🇱 · Valeriya Mykhaylova🇵🇱

    Different bases for the spin-1 density matrix are discussed to clarify the connection between its components and observables measured in heavy-ion collisions. The theoretical advantage of using the adjoint representation for spin matrices is emphasized. Next, the equilibrium spin density matrix and the corresponding Wigner function are introduced. With appropriate definitions of the energy-momentum and spin tensors, this framework allows for the formulation of perfect spin hydrodynamics in the same way as previously done for spin-1/2 particles. Together, these results provide a unified description of spin-1/2 and spin-1 particles.

    ↳ nucl-thhep-exhep-phActa Phys.Polon.B(2026)·4 citations
36. 36*

    Cosmological Dynamics of Multi-Axion Quintessence

    Supakorn Katewongveerachart · David J. E. Marsh🇬🇧

    One fundamental physics interpretation of Dark Energy Spectroscopic Instrument (DESI) results is that the observed accelerated expansion of the Universe is driven not by the cosmological constant, but by a slowly rolling scalar field, a natural model for which is an axion. In the ``string axiverse'' one expects not one, but many, axions. We thus investigate dark energy dynamics in a models with two, three, and four axions, and compute the prior probability for the dark energy equation of state parameters $(w_0,w_a)$ implied by priors on the fundamental parameters of the model conditioned weakly on the resulting cosmology. We find various interesting behaviours, for example where multiple fields can be in an oscillating regime while maintaining $w_0<-1/3$, and models with opposite sign for $w_a$ than in a single-field model. The prior probability in $(w_0,w_a)$ gains support away from the ``thawing quintessence'' behaviour preferred by DESI. Similarly, adding more axion fields and interactions among them leads to the prior support in the baryon acoustic oscillation distance measures moving further from the DESI data. Thus, interacting multifield models will not generically be preferred over simpler models unless very exotic dark energy evolution happens to be observed in future. The novel equations of state we illustrate may, however, be of relevance to models of early dark energy or inflation/reheating with multiple axions, and further study of multifield dynamics is warranted.

    ↳ astro-ph.COhep-ph2 citations
37. 37*

    Detectability and Template Distinguishability of the Dark Ages 21 cm Global Signal with Wide and Sparse Frequency Coverage

    Shintaro Yoshiura · Fumiya Okamatsu🇯🇵 · Tomo Takahashi🇯🇵

    The Dark Ages 21cm signal, observed at frequencies below 50 MHz, can serve as a powerful probe of cosmology, as the standard cosmological model predicts a well-defined 21cm spectral shape, while several non-standard scenarios produce distinctive spectral features. In this work, we present a Bayesian-evidence-based assessment of the detectability of representative Dark Ages 21cm signals and of the ability to discriminate among their spectral templates. We compare multiple cosmological signal templates within a common analysis framework, adopting physically motivated foreground models, optimistic error levels, and several observing strategies. This framework allows us to quantify how frequency coverage and sampling affect both the detectability and the ability to distinguish among different spectral shapes. Using Bayesian model comparison, we show that observations covering 1-50MHz provide evidence for a non-zero 21cm signal for all the models considered in this work. In particular, without observations below 3MHz, the standard cosmological signal cannot be detected even after 10,000h of integration, because the free-free absorption component is insufficiently constrained. Regarding template discrimination, the $\Lambda$CDM signal can be distinguished from other models except models with similar spectral shapes and an excess radio background model with a wide band observation. Furthermore, even with observations measured at 5 MHz intervals over the frequency range 1-50 MHz, the 21cm signal can be identified if the errors are sufficiently small. This indicates that the intrinsic 21cm spectral shape can be captured without foreground degeneracy even with a limited number of frequency channels. These results quantify, within the idealized assumptions adopted in this work, how much of the intrinsic Dark Ages 21cm spectral information can be retained under limited frequency sampling.

    ↳ astro-ph.COgr-qchep-ph0 citations
38. 38*

    Observation of $\bar{\Lambda }p\to K^{+}{\pi }^{+}{\pi }^{-}{\pi }^0$ and $\bar{\Lambda }p\to K^{+}{\pi }^{+}{\pi }^{-}2{\pi }^0$

    BESIII Collaboration: M. Ablikim🇨🇳 · M. N. Achasov🇷🇺 · P. Adlarson🇸🇪 · X. C. Ai🇨🇳 · C. S. Akondi🇮🇹 · R. Aliberti🇩🇪 · A. Amoroso🇮🇹 · Q. An🇨🇳 · Y. H. An🇨🇳 · Y. Bai🇨🇳 · O. Bakina🇷🇺 · Y. Ban🇨🇳 and 740 other authors

    Using $(10087\pm 44)\times 10^6$ $J/\psi$ events collected with the BESIII detector at a center-of-mass energy of $\sqrt{s}=3.097$ GeV, the antihyperon-nucleon annihilation processes $\bar{\Lambda }p\to K^{+}{\pi }^{+}{\pi }^{-}+k{\pi }^0$ ($k=1,2,3$) are studied at an incident $\bar{\Lambda }$ momentum of approximately 1.074 GeV/$c$. The reactions $\bar{\Lambda }p\to K^{+}{\pi }^{+}{\pi }^{-}{\pi }^0$ and $\bar{\Lambda }p\to K^{+}{\pi }^{+}{\pi }^{-}2{\pi }^0$ are observed for the first time, with corresponding cross sections ${\sigma }_{\bar{\Lambda }p\to K^{+}{\pi }^{+}{\pi }^{-}{\pi }^0}=8.5_{-1.1}^{+1.2}(stat.)\pm 0.4(syst.)$ mb and ${\sigma }_{\bar{\Lambda }p\to K^{+}{\pi }^{+}{\pi }^{-}2{\pi }^0}=7.9_{-1.7}^{+1.9}\pm 0.4$ mb. No significant signal is found for $\bar{\Lambda }p\to K^{+}{\pi }^{+}{\pi }^{-}3{\pi }^0$, and an upper limit of 7.2 mb is set at a 90\% confidence level. An evidence for the $K^{\ast }(892{)}^{+}$ resonance is seen in the $K^{+}{\pi }^0$ invariant mass spectrum $M_{K^{+}{\pi }^0}$ for $k=1$, and the corresponding cross section for $\bar{\Lambda }p\to K^{\ast }(892{)}^{+}{\pi }^{+}{\pi }^{-}$ is measured to be ${\sigma }_{\bar{\Lambda }p\to K^{\ast }(892{)}^{+}{\pi }^{+}{\pi }^{-}}=12.5_{-3.4}^{+3.8}\pm 1.2$ mb. Owing to the limited statistics, possible interference effects are not considered. These findings offer crucial input to deepen our understanding of the antihyperon-nucleon interactions.

    ↳ hep-exhep-phnucl-exPRL(2026)·1 citation
39. 39*

    Factorized neural posterior estimation for rapid and reliable inference of parameterized post-Einsteinian deviation parameters in gravitational waves

    Yong-Xin Zhang🇺🇸 · Tian-Yang Sun🇺🇸 · Chun-Yu Xiong🇺🇸 · Song-Tao Liu🇺🇸 · Yu-Xin Wang🇺🇸 · Shang-Jie Jin🇺🇸 · Jing-Fei Zhang🇺🇸 · Xin Zhang🇺🇸

    The direct detection of gravitational waves (GWs) by LIGO has strikingly confirmed general relativity (GR), but testing GR via GWs requires estimating parameterized post-Einsteinian (ppE) deviation parameters in waveform models. Traditional Bayesian inference methods like Markov chain Monte Carlo (MCMC) provide reliable estimates but suffer from prohibitive computational costs, failing to meet the real-time demands and surging data volume of future GW detectors. Here, we propose a factorized neural posterior estimation framework: we construct independent normalizing flow models for each of the nine ppE deviation parameters and effectively integrate prior information from other source parameters via a conditional embedding network. Leveraging a hybrid neural network with a convolutional neural network and a Residual Neural Network for feature extraction, our method performs rapid and statistically reliable posterior inference directly from binary black hole signals. Compared to conventional MCMC, our approach achieves millisecond-scale inference time with a speedup factor of $9\times 10^4$. Comprehensive validations show that the posterior estimates pass the Kolmogorov-Smirnov test and achieve empirical coverage probabilities close to theoretical targets. This work demonstrates the great potential of deep learning for GW parameter estimation and provides a viable technical solution for real-time GR tests with next-generation detectors.

    ↳ astro-ph.IMastro-ph.COgr-qchep-ph3 citations
40. 40*

    Resonant production of heavy particles during inflation and its gravitational wave signature

    Qi Chen🇨🇳 · Yuan Yin🇰🇷

    We show that a quadratic $U(1)$-breaking term, together with an effective chemical potential induced by a dimension five derivative coupling between the inflaton and the $U(1)$ current, can drive efficient particle production during inflation even when the $U(1)$ field is heavier than the Hubble scale. Notably, the chemical potential enables efficient production even when the $U(1)$-breaking mass is smaller than the effective diagonal mass. We compute the gravitational wave signal generated by this mechanism during inflation, derive the primordial tensor spectrum, and map it to the present day energy density ${\Omega }_{\mathrm{G}W}(f)$. Assuming the $U(1)$ field constitutes the dominant component of dark matter, this mapping fixes the characteristic frequency, which we compare with projected sensitivity curves of ongoing and proposed gravitational wave observatories. Finally, we argue that the same dynamics are accompanied by a cosmological collider signal, providing an independent cross validation of the framework.

    ↳ astro-ph.COhep-ph1 citation
41. 41*

    Bounds on the Tsallis Parameter from a deformed Neutrino Sector in the Early Universe

    Matias P. Gonzalez🇨🇱

    We generalize neutrino energy density content in the early universe near BBN era $T\simeq 1$ MeV within Tsallis nonextensive statistics. By using Curado-Tsallis constraints we obtain generalized distribution functions $f_q(E)$. We compute the generalized thermodynamic integral for the energy density ${\rho }_q$. We define a reescaling $R_{\rho }^{(\xi =+1)}(q)={\rho }_q/{\rho }^{\mathrm{std}}$ which is a ratio between the deformed energy density and the standard extensive case. The last was used to directly map and deform neutrino content via the effective number of neutrinos $N_{\mathrm{eff}}$. The deformation prediction was confronted against CMB$+$BAO and BBN data for $N_{\mathrm{eff}}$ by a joint/combined ${\chi }^2$ type-fit. We obtained the constraints $|q-1|\le 1.09\times 10^{-2}$ (95\% CL) and $|q-1|\le 1.32\times 10^{-2}$ (99\% CL) from the combined analysis by numerically calculating the best value of the Tsallis parameter $q_{\mathrm{best}}$.

    ↳ astro-ph.COhep-phEPJC(2026)·2 citations
42. 42*

    On the stability of Born-Infeld-regularised electroweak monopoles

    N E Mavromatos🇬🇷 · Sarben Sarkar🇬🇧

    The Cho-Maison monopole provides a monopole solution of the electroweak field equations, but possesses an infinite classical energy due to the Maxwell form of the hypercharge sector. Motivated by string-inspired effective field theories, we study the perturbative stability of the Cho-Maison monopole when the hypercharge kinetic term is regularised by a Born-Infeld extension, which renders the monopole energy finite. Focusing on the bosonic electroweak theory with an unmodified $SU(2{)}_L$ sector and a Born-Infeld U(1)_Y sector, we analyze linear fluctuations about the regularised monopole background. Using a complex tetrad and a spin-weighted harmonic decomposition, we reduce the fluctuation equations to coupled radial Schroedinger-type eigenvalue problems and examine the spectrum of the resulting operators. We extend the separation-of-variables framework developed by Gervalle and Volkov to this non-linear gauge-field setting. We show that, after appropriate gauge fixing and constraint elimination, the Born-Infeld deformation preserves the angular channel structure of the Maxwell theory and leads to a self-adjoint Sturm-Liouville type problem for the stability of the radial modes, with modified radial coefficients determined by the background Born-Infeld profile. The resulting operator represents a smooth deformation of the Maxwell case and retains positive kinetic weight. Our results provide plausible evidence for the stability of the Born-Infeld deformed monopole and, most importantly, a systematic framework for future numerical or variational studies aimed at a definitive spectral analysis.

    ↳ hep-thhep-ph4 citations
43. 43*

    Universal Relations and Correlation Analysis of Proto-Neutron Star Properties in Energy-Momentum Squared Gravity

    Sayantan Ghosh🇮🇳

    Proto-neutron stars (PNSs) are the hot, lepton-rich remnants of the core collapse supernovae, which go through a cooling phase and become cold, stable Neutron stars (NSs). Since PNSs are also superdense objects with strong gravitational fields, we can use them to probe general relativity (GR) in the high-curvature regime, similar to NSs. In this study, we analyze the macroscopic properties like mass, radius, compactness, tidal deformability, $f$-mode oscillations and gravitational binding energy of PNSs using four different relativistic mean-field (RMF) equations of state (EOSs) with fixed entropy per baryon ($S$ =1, 2) and varying the lepton fractions ($Y_l$). The variation of $S$ and $Y_l$ has a noticeable effect on these properties. Extending our study beyond GR, we explore these effects within the framework of Energy-Momentum Squared Gravity (EMSG). This modified gravity theory adds the squared energy-momentum terms to the field equations with a free parameter $\alpha$. In the weak-field regimes, EMSG remains indistinguishable from GR, but in the strong-field regimes, such as PNSs or NSs, it shows measurable deviations. Varying the free parameter $\alpha$, we observe significant changes in the macroscopic properties of the PNSs. After that, we focus on the universal relations of the macroscopic properties and the correlations of the universal relations. We find that, despite significant changes in the macroscopic properties induced by the variations of $S$, $Y_l$ and $\alpha$, the correlations remain strong and nearly unaffected.

    ↳ nucl-thgr-qchep-phJHEAp(2026)·4 citations
44. 44*

    Large Nc Truncations for SU(Nc) Lattice Yang-Mills Theory with Fermions

    Neel S. Modi🇺🇸 · Anthony N. Ciavarella🇺🇸 · Jad C. Halimeh🇩🇪 · Christian W. Bauer🇺🇸

    Quantum simulations of quantum chromodynamics (QCD) require a representation of gauge fields and fermions on the finitely many degrees of freedom available on a quantum computer. We introduce a truncation of lattice QCD coupled to staggered fermions that includes (i) a local Krylov truncation that generates allowed basis states; (ii) a maximum allowed electric energy per link; (iii) a limit on the number of fermions per site; and (iv) a truncation in the large N_c scaling of Hamiltonian matrix elements. Explicit truncated Hamiltonians for 1+1D and 2+1D lattices are given, and numerical simulations of string-breaking dynamics are performed.

    ↳ hep-lathep-phquant-ph10 citations
45. 45*

    Evaluating the Contribution of Active Galactic Nuclei to the Diffuse High-Energy Neutrino Flux

    Samyak Jain🇺🇸 · Dan Hooper🇺🇸 · Francis Halzen🇺🇸

    The detection of high-energy neutrinos from NGC 1068 and TXS-0506+56 suggests that active galactic nuclei (AGN) may contribute significantly to the the diffuse neutrino flux measured by IceCube. Using 10 years of publicly available IceCube data, we performed a systematic population analysis of X-ray-bright and gamma-ray-bright AGN to evaluate the extent to which this diffuse flux could originate from these sources. We find that gamma-ray-bright blazars can account for no more than 16\% of IceCube's total diffuse flux. Although we find no evidence of neutrino emission from gamma-ray-bright, non-blazar AGN, we cannot exclude the possibility that these sources contribute significantly to the diffuse flux. In contrast, we report (pre-trials) evidence of neutrino emission from several nearby, X-ray-bright, Seyfert-type AGN, including \mbox{NGC 1068} ($4.9\sigma$), SWIFT J1041.4-1740 ($2.6\sigma$), SWIFT J0202.4+6824A/B ($2.6\sigma$), SWIFT J0744.0+2914 (2.6$\sigma$), NGC 4151 ($2.5\sigma$), and NGC 3079 ($2.5\sigma$). Although not fully conclusive, these results suggest that IceCube may be detecting neutrinos from a larger population of Seyfert galaxies. The fact that these sources are not gamma-ray bright indicates that their neutrino production must be taking place in optically thick environments, such as in the coronae surrounding these galaxies' supermassive black holes. We also identify a $4.2\sigma$ correlation between the neutrinos detected by IceCube and members of the Swift-BAT catalog of X-ray-bright AGN, although this correlation is dominated by NGC 1068. We estimate that this class of sources contributes between 11.2\% and the entirety of IceCube's total diffuse neutrino flux. These results strengthen the emerging case for the prevalence of gamma-ray-obscured AGN as significant sources of high-energy neutrinos.

    ↳ astro-ph.HEastro-ph.COastro-ph.GAhep-phJCAP(2026)·3 citations
46. 46*

    Wilson loops with neural networks

    Verena Bellscheidt🇺🇸 · Nora Brambilla🇩🇪 · Andreas S. Kronfeld🇺🇸 · Julian Mayer-Steudte🇩🇪

    Wilson loops are essential objects in QCD and have been pivotal in scale setting and demonstrating confinement. Various generalizations are crucial for computations needed in effective field theories. In lattice gauge theory, Wilson loop calculations face challenges, including excited-state contamination at short times and the signal-to-noise ratio issue at longer times. To address these problems, we develop a new method by using neural networks to parametrize interpolators for the static quark-antiquark pair. We construct gauge-equivariant layers for the network and train it to find the ground state of the system. The trained network itself is then treated as our new observable for the inference. Our results demonstrate a significant improvement in the signal compared to traditional Wilson loops, performing as well as Coulomb-gauge Wilson-line correlators while maintaining gauge invariance. Additionally, we present an example where the optimized ground state is used to measure the static force directly, as well as another example combining this method with the multilevel algorithm. Finally, we extend the formalism to find excited-state interpolators for static quark-antiquark systems. To our knowledge, this work is the first study of neural networks with a physically motivated loss function for Wilson loops.

    ↳ hep-lathep-phnucl-thPRD(2026)·2 citations
47. 47*

    Gravitational-Wave Signals for Supernova Explosions of Three-Dimensional Progenitors

    Alessandro Lella (1,2,3,4)🇮🇹 · Giuseppe Lucente (5)🇺🇸 · Daniel Kresse (6)🇩🇪 · Robert Glas (6)🇩🇪 · H.-Thomas Janka (6)🇩🇪 · Alessandro Mirizzi (1,2) ((1) Dipartimento Interateneo di Fisica "Michelangelo Merlin", Bari, (2) INFN, Bari, (3) Universita degli Studi di Padova, (4) INFN, Padova, (5) SLAC Nat. Acc. Lab., CA, (6) MPI Astrophysics, Garching)🇮🇹

    Core-collapse supernovae (SNe) are sources of gravitational waves (GWs) produced by hydrodynamical instabilities and highly time-dependent anisotropies of the neutrino radiation. In this work we analyze both contributions to the GW signal for two state-of-the-art three-dimensional (3D) SN models computed with the Prometheus-Vertex neutrino-hydrodynamics code. In contrast to the far majority of models analyzed for GWs so far, our core-collapse simulations were started with 12.28 M_sun (18.88 M_sun) progenitors, whose final hour (7 min) of convective oxygen-shell burning was computed in 3D and featured a vigorous oxygen-neon shell merger. The corresponding large-scale asymmetries in the oxygen layer are conducive to buoyancy-aided neutrino-driven explosions. The models were continuously evolved in 3D from the pre-collapse evolution until 5.11 s (1.68 s) after the core bounce. The GW signals result from the well-known dynamical phenomena in the SN core such as prompt postshock convection, neutrino-driven convection, the standing accretion shock instability, proto-neutron star oscillations, and anisotropic ejecta expansion. They do not exhibit any new or specific features that can be unambiguously connected to the powerful pre-collapse activity in the progenitors, but we identify interesting differences compared to results in the literature. We also discuss measurement prospects by interferometers, confirming that GW signals from future Galactic SNe will be detectable with existing and next-generation experiments working in the frequency range f ~ 1-2000 Hz.

    ↳ astro-ph.HEgr-qchep-phPRD(2026)·11 citations

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