Fri·Mar 20, 2026Friday·March 20, 2026

1. 01*

   Axions at the meV Crossroads: Theory, Cosmology, Astrophysics, and Experiments

   Michele Cicoli🇮🇹 · Francesco D'Eramo🇮🇹 · Luca Di Luzio🇮🇹 · Damiano F. G. Fiorillo🇮🇹 · Maurizio Giannotti🇪🇸 · Alicia Gomez🇪🇸 · Diego Guadagnoli🇫🇷 · Mathieu Kaltschmidt🇪🇸 · Bradley J. Kavanagh🇪🇸 · Alessandro Lella🇮🇹 · Giuseppe Lucente🇺🇸 · David J. E. Marsh🇬🇧 and 9 other authors

   The meV mass range has emerged as a focal point in axion physics, where advances in theory, cosmology, astrophysics, and experimental techniques converge. Axions in this mass range are theoretically well motivated, can arise in ultraviolet-complete models, and can have significant cosmological impacts as dark matter or dark radiation. In parallel, their efficient production in stellar and supernova environments provides powerful astrophysical probes. Here, we provide a comprehensive overview of meV axions across these domains, highlighting both established results and open questions. We discuss the theoretical underpinnings of meV axions, their cosmological and astrophysical signatures, and the diverse experimental strategies -- ranging from helioscopes and haloscopes to quasiparticle systems and large-volume Cherenkov detectors -- that aim to explore this regime. The convergence of these approaches emphasizes the pivotal role of the meV mass range for axion discovery in the coming years, identifying meV axions as a key probe for testing beyond-Standard-Model physics. This review document is the direct outcome of the discussions at the dedicated workshop "The meV Mass Axion Frontier: Challenges and Opportunities", held at Laboratori Nazionali di Frascati (IT) on 27--28 October 2025, and organized by the EU funded COST Action "Cosmic WISPers in the Dark Universe: Theory, astrophysics, and experiments" (CA21106, https://www.cost.eu/actions/CA21106). Its aim is to provide an overview of current efforts in meV axion research, their motivations, and the research goals that animate the community involved in this search.

   hep-phastro-ph.HEhep-exhep-thJCAP(2026)·6 citations
2. 02*

   Stellar Bounds on a Model with Photon-Photino Oscillation

   Bernard Teles de Menezes🇧🇷 · José Abdalla Helayël-Neto🇧🇷

   In this paper, we pursue an investigation of the consequences of a mixing between supersymmetric partners - the photon and photino - analogous to the so-called Primakoff effect, but induced by a Lorentz-symmetry violating (LSV) fermionic-condensate background. In our framework, the LSV parameters are introduced as members of a non-dynamical superfield. As a consequence, we show that naturally there appears a mixing term between the gauge boson and the gaugino, which can be readily seen in the superspace/superfield approach. We inspect the kinetic photon-photino mixing matrix in the scenario of stellar physics which we apply our results to. Bounds on the strength of the fermionic LSV background are can be set by invoking the energy loss argument and the solar data we adopt.

   hep-phastro-ph.HEhep-thPLB(2026)·0 citations
3. 03*

   Nuclear transverse momentum dependent gluon density at low $x$ and inclusive soft hadron production in proton-lead collisions at LHC

   A. V. Lipatov🇷🇺 · G. I. Lykasov🇷🇺 · M. A. Malyshev🇷🇺

   We report the results of calculations of inclusive soft hadron production in proton-lead collisions at the LHC in the framework of modified quark-gluon string model (QGSM) extended to $pA$ interactions. Our consideration involves the nuclear modification of previously proposed transverse momentum dependent (TMD, or unintegrated) gluon density in a proton, which provides a self-consistent simultaneous description of numerous HERA and LHC data on $pp$, $ep$ and $\gamma p$ processes. Such nuclear modification is based on well established property of geometrical scaling from nucleons to nuclei. Focusing on the region of small $x$ and low scales, we obtain predictions for transverse momentum spectra of pions and kaons at $p_T\le 1$~GeV. Our results are compared with recent data reported by the CMS, ATLAS and ALICE Collaborations at $\sqrt{s}=5.02$~TeV. We find that the developed approach provides a better description of low-$p_T$ data than the predictions made by other groups.

   hep-ph0 citations
4. 04*

   QCD and electroweak phase transitions with hidden scale invariance: implications for primordial black holes, quark-lepton nuggets and gravitational waves

   Joshua Cesca · Archil Kobakhidze🇦🇺

   We study the cosmological implications of the minimal non-linear realisation of scale invariance within the Standard Model (SM). This framework provides a technically natural explanation for the hierarchy between the Planck scale and the electroweak scale and introduces only a light, feebly coupled dilaton field beyond the SM particles. Although the model is almost indistinguishable from the minimal SM at low energies, its cosmological consequences differ dramatically. In particular, the electroweak Higgs field remains trapped in the symmetric phase until the Universe cools to very low temperatures, $T_c^{(\chi )}\sim 28$ MeV, where the first-order QCD chiral symmetry-breaking phase transition triggers the electroweak phase transition. This scenario offers intriguing possibilities for the production of primordial black holes, low-frequency gravitational waves, and multi-quark and lepton nuggets, which we explore in some detail using simplified approximations.

   hep-phastro-ph.COhep-th0 citations
5. 05*

   Revisiting Bino-Slepton Coannihilation Dark Matter in Light of Recent Experimental Results

   Koichi Hamaguchi🇯🇵 · Atsuya Niki🇯🇵 · Kwok Hei To🇯🇵

   Despite being a simple and well-motivated thermal relic scenario, coannihilation dark matter (DM) has remained largely unexplored experimentally due to the difficulty of probing its nearly degenerate mass spectrum. Recent LHC searches, however, have significantly improved the sensitivity to such compressed spectra, motivating a reassessment of the viable parameter space. We revisit the bino-slepton coannihilation scenario in supersymmetric (SUSY) models, incorporating the latest experimental results. We first focus on the minimal scenario, in which only the bino-like neutralino and left- or right-handed sleptons are light ($O(100)$ GeV), with all other SUSY particles decoupled. We find that the dark matter mass is constrained to be in the range of about 170-420 GeV (130-430 GeV) for left-handed (right-handed) slepton coannihilation, with lower bounds set by recent LHC searches. We then investigate scenarios with light higgsino, where direct detection experiments impose strong constraints on the higgsino mass. We also discuss the implications of these constraints for the muon $g-2$ in the so-called BHR, BHL, and BLR scenarios with coannihilation DM, and find that the combined LHC and LZ limits constrain the SUSY contribution to $|\Delta a_{\mu }^{\mathrm{SUSY}}|\lesssim 1.2\times 10^{-9}$.

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

   $d_{N\Omega }$ production in $\Omega d$ scattering process

   Quan-Yun Guo🇨🇳 · Jing Liu🇨🇳 · Dian-Yong Chen🇨🇳

   In the present work, we propose to investigate the production of $d_{N\Omega }$ in the ${\Omega }^{-}d\to p{d}_{N\Omega }^{-}$ process by utilizing an effective Lagrangian approach, where $d_{N\Omega }$ is identified as $N\Omega$ bound state with the binding energy $E_b=2.46$ MeV. Experimentally, the J-PARC hadron facility proposed to investigate the $K^{-}p\to {\Omega }^{-}{\bar{K}}^{(\ast )0}{K}^{+}$ process, which is expected to yield an $\Omega$ beam with the momentum of approximately 3 GeV. Additionally, theoretical studies of the $\psi (2S)\to {\Omega }^{-}{\bar{\Omega }}^{+}$ process at BESIII provided an $\Omega$ beam with the momentum of 774 MeV. Considering these two potential $\Omega$ beam sources, our estimations show that for the ${\Omega }^{-}d\to p{d}_{N\Omega }^{-}$ process, the cross sections are $\left(329.7_{-49.6}^{+26.9}\right)$ $\mu$b, $\left(174.0_{-38.2}^{+26.5}\right)$ $\mu$b, $\left(16.9_{-7.7}^{+7.4}\right)$ $\mu$b, and $\left(2.0_{-1.4}^{+1.8}\right)$ $\mu$b at $P_{\Omega }=$ 0.7, 0.9, 2.0, and 4.0 GeV, respectively, where the central values are estimated with ${\Lambda }_r=1.0$ GeV, and the errors come from the variation of ${\Lambda }_r$ from 0.8 to 1.2 GeV. We also estimate the differential cross sections, which reach the maximum at the forward angle limit. In addition, since the $d_{N\Omega }$ dibaryon predominantly decays into $\Xi \Lambda$. Therefore, we further investigate the ${\Omega }^{-}d\to p{\Xi }^{-}\Lambda$ process and estimate the relevant cross sections. It is expected that the present estimations can be tested by further experimental measurements at J-PARC and STCF in the future.

   hep-phEPJC(2026)·0 citations
7. 07*

   Cosmological Implications of the Slingshot Effect: Gravitational Waves, Primordial Black Holes and Dark Matter

   Maximilian Bachmaier🇩🇪 · Gia Dvali🇩🇪 · Juan Sebastián Valbuena-Bermúdez🇪🇸 · Michael Zantedeschi🇮🇹

   In this paper, we explore the implications of the so-called slingshot effect. It represents a rather general phenomenon occurring when a localized source, such as a monopole, quark, or a $D$-brane, crosses a domain wall separating the confined (Higgsed) and unconfined (Coulomb) phases of the crossing source. The crossover is accompanied by a stretched ``string'' of proper co-dimensionality that confines the source to the domain wall. The effect takes place for different setups, such as phase transitions leading to confinement, both electric and magnetic, as well as in string theoretic inflation with $D$-branes. We discuss the role of the phenomenon in sourcing gravitational waves and dark matter in the form of Kaluza-Klein gravitons. We also show that the slingshot effect can lead to the formation of primordial black holes in observationally interesting mass ranges for dark matter and high-energy cosmic rays.

   hep-phhep-thPhys.Dark Univ.(2026)·1 citation
8. 08*

   Higgs boson decay to massive bottom quarks at order ${\alpha }_s^4$ induced by top-quark Yukawa couplings

   Jian Wang🇨🇳 · Xing Wang🇨🇳 · Yefan Wang🇨🇳

   The Higgs boson decay to massive bottom quarks has the largest branching ratio. The decay is mainly induced by the bottom-quark Yukawa coupling with the decay rate calculated up to $O({\alpha }_s^4)$ assuming the massless final-state bottom quark. The top-quark Yukawa coupling induced contribution starts at $O({\alpha }_s^2)$, and exhibits logarithmic and power enhancements, making the perturbative expansion converge slowly, which is a feature not present in the hadronic Higgs boson decay. We present a calculation of such contributions at $O({\alpha }_s^4)$ to the decay into massive bottom quarks in which the squared amplitudes contain two top-quark Yukawa couplings and the final state must include at least a bottom quark pair. We find that they increase the decay width, relative to the result up to $O({\alpha }_s^3)$, by $0.4\%$, larger than the experimental precision at future lepton colliders, and reduce the scale dependence significantly down to $0.4\%$.

   hep-phhep-exJHEP(2026)·1 citation
9. 09*

   Electroweak phase transitions in a $U(1{)}_D$ extension of the standard model with dimension-six operators: Gravitational waves and LHC signatures

   Arka Bhattacharyya🇮🇳 · Sanjoy Biswas🇮🇳 · Saurabh Niyogi🇮🇳

   We investigate the possibility of realizing strong first-order electroweak phase transition (SFOEWPT) in an effective field theory framework where the Standard Model is extended with a complex scalar singlet ($\varphi$) charged under a local $U(1{)}_D$ gauge group. The tree-level scalar potential contains a dimension-six term of the form $|H{|}^2|\varphi {|}^4$. We show that this higher-dimensional operator plays a crucial role in the phase transition dynamics by weakening the correlation between the Higgs-singlet portal coupling and the scalar mixing angle that typically constrains singlet-extended models. Consequently, SFOEWPT can be achieved over a significantly extended region of parameter space. The strength of the phase transition is primarily driven by the vacuum expectation value (VEV) of the singlet scalar which plays a central role in this analysis. We analyze the phase transition in this model and identify regions of parameter space consistent with SFOEWPT. The resulting phase transition can generate stochastic gravitational-wave signals potentially observable at future interferometers. The extended scalar sector in presence of the dimension-six operator also leads to distinctive multi-scalar production signatures at the LHC, intimately correlated with the singlet scalar VEV.

   hep-phPRD(2026)·1 citation
10. 10*

    Signatures of the $\Omega (2012{)}^{-}$ state in ${\Xi }^{\ast }\bar{K}$ Correlation Functions

    Jia-Xin Lin🇨🇳 · Pablo Encarnación🇪🇸 · Albert Feijoo🇪🇸 · Miguel Albaladejo🇪🇸

    We investigate the $\Omega (2012)$ resonance in the strangeness $S=-3$ sector within a coupled-channel chiral unitary approach and present the first quantitative predictions for femtoscopic correlation functions directly sensitive to its dynamics. The $\Omega (2012)$ is dynamically generated as a quasi-bound ${\Xi }^{\ast }\bar{K}$-$\Omega \eta$ molecular state, with its coupling to the $\Xi \bar{K}$ channel driven by $d$-wave transitions. Model parameters are constrained by the measured mass, width, and the Belle determination of the branching fraction ${\mathcal{R}}_{\Xi \bar{K}}^{\Xi \bar{K}\pi }$, yielding $M_{\Omega (2012)}=(2012.53\pm 0.73)$ MeV and ${\Gamma }_{\Omega (2012)}=(4.05\pm 0.13)$ MeV. Within this framework, we compute the femtoscopic correlation functions of the ${\Xi }^{\ast 0}{K}^{-}$, ${\Xi }^{\ast -}{\bar{K}}^0$, and ${\Omega }^{-}\eta$ systems. The ${\Xi }^{\ast }\bar{K}$ correlation functions exhibit pronounced near-threshold structures that arise from the proximity of the $\Omega (2012)$ pole, demonstrating an exceptional sensitivity to its position and coupled-channel composition. In particular, the ${\Xi }^{\ast 0}{K}^{-}$ correlation function is identified as a clean and highly selective probe of the $\Omega (2012)$ resonance. These results establish femtoscopic correlation measurements as powerful tools for extracting resonance properties beyond conventional invariant-mass analyses and provide concrete theoretical benchmarks for upcoming experimental studies aimed at elucidating the molecular nature of the $\Omega (2012)$.

    hep-phPLB(2026)·3 citations
11. 11*

    A Systematic Approach to Finite Multiloop Feynman Integrals

    Prasanna K. Dhani🇨🇭 · Konstantinos Pyretzidis🇪🇸 · Selomit Ramírez-Uribe🇲🇽 · José Ríos-Sánchez🇪🇸 · German F.R. Sborlini🇪🇸 · Surabhi Tiwari🇪🇸 · Germán Rodrigo🇪🇸

    Finite Feynman integrals have been advocated as the optimal components for constructing a basis of master integrals in multiloop calculations, due to their improved analytic and numerical properties. In this paper, we show how the Loop-Tree Duality (LTD) is particularly well suited for systematically identifying finite integrals, as it makes the origin of infrared and threshold singularities fully transparent at the integrand level. This clear separation of singular and non-singular contributions enables a more efficient strategy for isolating and promoting finite integrals, thereby streamlining both reduction and numerical evaluation. We present a new strategy based on numerator and raised propagator Ansätze that provides results similar to other methods, although in a clearer and compact way. While this construction and other approaches establish a robust foundation, they often produce integrands that exhibit a rapid growth in the ultraviolet (UV) regime. To mitigate this bad UV behaviour, we introduce a generalized set of integrands fully defined within LTD. This new set is inherently infrared-finite and frequently free of threshold singularities, offering a more versatile framework for high-order calculations.

    hep-phhep-exhep-th4 citations
12. 12*

    Correlator of heavy-light quark currents in HQET in the large ${\beta }_0$ limit

    Andrey G. Grozin🇷🇺

    The perturbative contribution to the correlator of two heavy-light quark currents in HQET expanded in light-quark masses up to quadratic terms is calculated at the leading order in $1/{\beta }_0$. Ultraviolet and infrared renormalon poles of Borel images of the Wilson coefficients are discussed.

    hep-ph0 citations
13. 13*

    Investigating a strong first-order electroweak phase transition in the RxSM at future linear $e^{+}{e}^{-}$ colliders and LISA

    Johannes Braathen🇩🇪 · Sven Heinemeyer🇪🇸 · Carlos Pulido Boatella🇪🇸 · Alain Verduras Schaeidt🇩🇪

    The general real singlet extension of the Standard Model (SM), the RxSM, is one of the simplest theories Beyond-the-Standard Model (BSM) that can accommodate a strong first-order electroweak phase transition (SFOEWPT). We investigate the possible thermal histories of the scalar potential in the RxSM, and the regions of the model parameter space in which SFOEWPT can be realised. We then explore complementary avenues to probe such scenarios experimentally: either using searches for a stochastic background of gravitational waves (GWs), or using searches for di-Higgs production processes at future collider experiments, focusing on the case of a high-energy $e^{+}{e}^{-}$ collider. An important aspect of our work is that one-loop corrections to all relevant trilinear scalar couplings are consistently included both in the calculation of dynamics of the electroweak phase transition (EWPT) and in collider processes. We find entirely different phenomenological signatures for different parts of the RxSM parameter space giving rise to SFOEWPTs. On the one hand, if the SFOEWPT is driven by the singlet field, the 125 GeV Higgs boson is very SM-like and signs of BSM physics would be difficult to find at colliders, but strong GW signals could be produced. On the other hand, in scenarios where a SFOEWPT is driven by the doublet field, BSM deviations in properties of the detected Higgs boson, particularly in its trilinear self-coupling, typically lead to observable signals at colliders, while detectable GW signals are much more challenging to achieve. This work highlights the complementarity of collider experiments and cosmological observations to determine the dynamics of the EWPT and reconstruct the shape of the Higgs potential realised in Nature.

    hep-phEur.Phys.J.Plus(2026)·0 citations
14. 14*

    From N- to (p,N)- Inflationary Attractors in view of ACT

    C. Pallis🇬🇷

    We review two types of fractional Kaehler potentials $K$ which reduce, along the inflationary path, to the form $N/(1-{\varphi }^{q_{\mathrm{M}}}{)}^p$ with $q_{\mathrm{M}}=1$ or $2$ and $0.1\le p\le 10$. Their coexistence, within a non-linear sigma model, with chaotic inflationary potentials of the form ${\varphi }^n$ (where $n=2$ or $4$) determines, independently from $q_{\mathrm{M}}$ and $n$, a class of $(p,N)$-inflationary attractors which leads to observables compatible with the ACT DR6. An implementation of these models in the context of supergravity can be also achieved by introducing two chiral superfields and a monomial superpotential, linear with respect to the inflaton-accompanying field, and supplementing the $K$'s above with a shift symmetry. Although inflation is attained for subplanckian inflaton values, the tensor-to-scalar ratio obtained for certain $N$ values can be possibly observable in the near future.

    hep-phastro-ph.COhep-thPoS(2026)·0 citations
15. 15*

    Probing the Color-Octet Mechanism via Dihadron Fragmentation in ${\chi }_b$ Decays

    Zhi-Guo He🇨🇳 · Guanghui Li🇨🇳 · Yu-Jie Tian🇨🇳 · Xin-Kai Wen🇨🇳 · Bin Yan🇨🇳

    The color-octet (CO) mechanism is a cornerstone of non-relativistic QCD, yet its long-distance matrix elements remain limited, preventing stringent tests of the theory. We demonstrate that the Artru-Collins asymmetry in hadronic decays of the $P$-wave bottomonium state ${\chi }_{b2}$ provides a direct probe of CO dynamics. The asymmetry arises exclusively from the CO decay channel, whereas the color-singlet (CS) contribution affects only the unpolarized rate, so that a nonzero signal constitutes unambiguous evidence of the CO mechanism. This observable provides a novel way to extract the ratio ${\rho }_8$ between CO and CS matrix elements. Focusing on $e^{+}{e}^{-}\to {\rm Y}(2S)\to \gamma {\chi }_{b2}$ at Belle, we show that the asymmetric beam configuration preserves the asymmetry in the laboratory frame and avoids the strong suppression present in the center-of-mass frame. With the Belle II dataset, ${\rho }_8$ could be determined with sufficient precision to address the long-standing discrepancy between the lattice calculations and phenomenological determinations.

    hep-phhep-exnucl-exnucl-th3 citations
16. 16*

    Hadron production through Higgs decay at next-to-leading order in the general-mass variable-flavor-number scheme

    S. Mohammad Moosavi Nejad🇮🇷

    It is known that about $60\%$ of all Higgses produced at the CERN-LHC decay into a pair of bottom quarks. Bottoms quickly hadronize, in most cases, into bottom-flavored (B) hadrons before they decay. Therefore, the study of scaled-energy distribution of B-mesons in the decay process $H\to B+Jets$ can be considered as a channel to search for the Higgs characteristics. In all previous studies, authors have ignored the mass effect of b-quarks as well as B-mesons by working in the massless scheme. In this work we, for the first time, study the mass effect of b-quarks as well as produced mesons on the scaled-energy ($x_B$) distribution of B-mesons by working in the massive scheme or general-mass variable-flavor-number scheme (GM-VFNs). We find that the meson mass is responsible for a significant enhancement of partial decay width in the low-$x_B$ region while the b-quark mass leads to an enhancement of the partial decay rate in the peak region and above.

    hep-phPRD(2026)·0 citations
17. 17*

    Two-body strong decays of the pseudoscalar hidden-charm tetraquark states via the QCD sum rules

    Yu-Hang Xu🇨🇳 · Zhi-Gang Wang🇨🇳

    In this work, we study the properties of the pseudoscalar hidden-charm tetraquark states by analyzing their two-body strong decays via the QCD sum rules based on rigorous quark-hadron duality. We take into account the vacuum condensates up to dimension 5 on the QCD side, and obtain the hadronic coupling constants. At last, we obtain the total decay widths $\Gamma (Z_c^{-})=326.20_{-3.11}^{+4.26}$ MeV and $\Gamma (Z_c^{+})=91.84_{-0.76}^{+0.96}$ MeV, respectively, where the $Z_c^{+}$($J^{PC}=0^{-+}$) and $Z_c^{-}$($J^{PC}=0^{--}$) denote the pseudoscalar hidden-charm tetraquarks with the diquark-antidiquark structures $[uc{]}_A[\bar{d}\bar{c}{]}_V-[uc{]}_V[\bar{d}\bar{c}{]}_A$ and $[uc{]}_A[\bar{d}\bar{c}{]}_V+[uc{]}_V[\bar{d}\bar{c}{]}_A$, respectively.

    hep-phInt.J.Mod.Phys.A(2026)·0 citations
18. 18*

    Direct $CP$ violation in $D^{\pm }\to {\pi }^{\pm }{\pi }^{+}{\pi }^{-}$ with $a_0^0(980)-f_0(980)$ mixing

    Shi-Ji Cao🇨🇳 · Jing-Juan Qi🇨🇳 · Yi-Fan Zhao🇨🇳 · Chao Wang🇨🇳 · Zhen-Yang Wang🇨🇳 · Xin-Heng Guo🇨🇳

    We investigate the direct $CP$ violation in the decay $D^{\pm }\to {\pi }^{\pm }{\pi }^{+}{\pi }^{-}$ incorporating the $a_0^0(980)$-$f_0(980)$ mixing mechanism. The integrated mixing intensities ${\overline{\xi }}_{fa}$ and ${\overline{\xi }}_{af}$ are calculated using meson masses and coupling constants extracted from various theoretical models and experimental data, yielding values of appreciable magnitude. We find that when the invariant mass of the ${\pi }^{+}{\pi }^{-}$pair lies near the $f_0(980)$ resonance, this isospin breaking mechanism can enhance the $CP$ asymmetry. The enhancement is particularly pronounced when $f_0(980)$ carries a significant $n\bar{n}$ quark component and the $f_0(980)$ and $\sigma (600)$ mixing angle is approximately $26^{\circ }$. It is emphasized that the $a_0^0(980)$-$f_0(980)$ mixing mechanism can be taken into account in both theoretical and experimental studies of $CP$ violation in $B$ or $D$ meson decays.

    hep-phCPC(2026)·0 citations
19. 19*

    Transverse spin effects and light-quark dipole moments at colliders

    Xin-Kai Wen🇨🇳 · Bin Yan🇨🇳 · Zhite Yu🇺🇸 · C.-P. Yuan🇺🇸

    In this talk, we present novel methods to investigate light-quark dipole interactions at colliders. Our approach includes: (1) measuring azimuthal asymmetries of a collinear dihadron in semi-inclusive deep inelastic lepton scattering off an unpolarized proton target at the Electron-Ion Collider, and (2) utilizing azimuthal asymmetries of dihadron $(h_1{h}_2)$ produced in association with an additional hadron $h^{\prime }$ at lepton colliders. These asymmetries provide a unique means to observe transversely polarized quarks, which arise from quantum interference and are exclusively sensitive to dipole interactions at the leading power of the new physics scale. Consequently, they exhibit a linear dependence on the dipole couplings, free from contamination by other new physics effects. This approach has the potential to significantly strengthen current constraints by one to two orders of magnitude. By combining all possible channels of $h^{\prime }$, this novel approach enables the disentanglement of the up- and down-quark dipole moments. Additionally, by controlling the electron's longitudinal polarization and the center-of-mass energy, it separates the contributions mediated by photon and weak boson. Furthermore, it allows for a simultaneous determination of both real and imaginary parts of the dipole couplings, offering a new avenue for investigating potential $CP$-violating effects at high energies.

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

    The impact of prescriptions in phenomenological extractions of Transverse Momentum Dependent distributions

    Matteo Cerutti🇫🇷 · Andrea Simonelli🇮🇹

    We investigate the impact of phenomenological prescriptions in the Collins-Soper-Sterman (CSS) approach for global extractions of Transverse Momentum Distributions (TMDs). We show that fits to low-energy Drell-Yan data with different choices of $b_{\ast }$ prescription yield equally good agreement with data and similar TMDs at small partonic transverse momentum. In contrast, sizable differences emerge at intermediate transverse momentum region, significantly affecting the predictions for high-energy Drell-Yan processes. Our results demonstrate that the $b_{\ast }$ prescription represents an intrinsic source of theoretical uncertainty in the CSS approach, introducing systematic effects that influence TMD extractions and their interpretation. At the same time, our analysis emphasizes the interplay between data at different energy scales in assessing the effect of phenomenological prescriptions in TMD fits adopting the CSS framework.

    hep-phhep-exhep-latEPJC(2026)·5 citations
21. 21*

    Gamma-ray production in the cosmic-ray -- dark matter scattering as a probe of the axion-like particle -- proton interaction

    Victor P. Goncalves🇧🇷 · Emmanuel Moulin🇫🇷 · Igor Reis🇫🇷 · Aion Viana🇧🇷

    The production of very-high-energy (VHE, $E_{\gamma }\gtrsim 100$ GeV) gamma rays resulting from the scattering of high-energy cosmic-ray protons off axion-like particles (ALPs) populating the dark matter halo of the Milky Way is investigated. By employing the latest instrument response functions for current and future facilities, we demonstrate that ground-based VHE gamma-ray observatories, such as H.E.S.S., CTAO, and SWGO, provide a promising and complementary avenue to probe the yet uncharted ALP-proton coupling $g_{ap}$. Our results show that these experiments can reach sensitivity to couplings above $10^{-2}$ in the $1-10^8$ eV ALP mass range, a region that remains largely unexplored by supernova and neutron star cooling observations. Interestingly, we demonstrate that this search channel is capable of probing QCD axion dark matter models, assuming two benchmark models for it: the Kim-Shifman-Vainshtein-Zakharov (KSVZ) Dine-Fischler-Srednicki-Zhitnitsky (DFSZ) models, specifically within the MeV mass range. These findings highlight the potential of VHE gamma-ray astronomy to provide unique constraints on the interaction between ALPs and the baryonic sector.

    hep-phastro-ph.HEPRD(2026)·1 citation
22. 22*

    Neutrino mass and leptogenesis in the non-SUSY modular $A_5^{\prime }$ inverse seesaw model

    Xianshuo Zhang🇨🇳 · Yakefu Reyimuaji🇨🇳

    A non-supersymmetric inverse seesaw model of neutrino mass based on the $A_5^{\prime }$ modular symmetry is presented. This framework provides a combined explanation for neutrino masses, mixing, and the cosmic baryon asymmetry through leptogenesis. Three concrete realizations are constructed, and their phenomenological predictions are analyzed. The results are not only compatible with the measured neutrino oscillation parameters within the current experimental 3$\sigma$ ranges, but also provide predictions for the neutrino mass ordering, Dirac and Majorana CP-violating phases, and the effective Majorana mass in neutrinoless double beta decay. The model further realizes TeV-scale leptogenesis consistent with the observed baryon asymmetry, rendering the scenario testable in both low-energy neutrino experiments and high-energy collider searches.

    hep-phPRD(2026)·5 citations
23. 23*

    Searching for dark matter X-ray lines from the Large Magellanic Cloud with eROSITA

    Jorge Terol Calvo🇮🇹 · Marco Taoso🇮🇹 · Andrea Caputo🇨🇭 · Michela Negro🇺🇸 · Marco Regis🇮🇹

    We perform a search for an X-ray monochromatic line arising from dark matter (DM) decay in the halo of the Large Magellanic Cloud. An emission line can be expected from two well-motivated DM candidates: sterile neturinos and axion-like particles (ALPs). We analyze the eROSITA-DE DR1 datasets in the energy range between 1 and 9 keV. No evidence for a DM line is found, and we set lower limits on the DM lifetime. We then recast these bounds into upper limits on the active-sterile neutrino mixing angle ${\sin }^2(2\theta )$ and on the ALP to photon coupling $g_{a\gamma }$, for DM masses between 2 and 18 keV. These results set new strong constraints for masses below 5 keV.

    hep-phastro-ph.HE5 citations
24. 24*

    Hidden-charm pentaquarks: Electromagnetic structure in a diquark--diquark--antiquark model

    U.Ozdem🇹🇷

    We systematically investigate the electromagnetic properties of exotic states whose internal structures remain uncertain and for which different models have been proposed. In this work, we focus on the magnetic dipole moments of hidden-charm pentaquark states using QCD light-cone sum rules with four distinct interpolating currents. The analysis accounts for contributions from both light and charm quark sectors, as well as higher-dimensional operators, ensuring convergence of the operator product expansion and dominance of the ground-state pole. Our results demonstrate a strong dependence of the magnetic moments on the internal quark configurations and spin alignments, revealing substantial variations among the different currents despite identical quark content and quantum numbers. Comparisons with existing studies indicate that while molecular-type predictions show general agreement, compact configurations yield markedly different values, including significant differences in sign and magnitude. These findings therefore underscore the sensitivity of electromagnetic observables to the internal structure of exotic hadrons and highlight their potential as probes to discriminate between competing structural models for spin-parity assignments and underlying quark dynamics.

    hep-phhep-exhep-latEPJC(2026)·4 citations
25. 25*

    A global analysis of Energy-Energy Correlation data: determination of ${\alpha }_S$ and non-perturbative QCD parameters

    Ugo Giuseppe Aglietti🇮🇹 · Giancarlo Ferrera🇮🇹 · Lorenzo Rossi🇮🇹

    We present a comprehensive global analysis of Energy-Energy Correlation (EEC) data in electron-positron annihilation into hadrons, spanning a wide range of center-of-mass energies ($7.7\text{GeV}\le \sqrt{s}\le 91.2\text{GeV})$. In the back-to-back (two-jet) region, we resum to all orders the logarithmically-enhanced contributions up to next-to-next-to-next-to-leading logarithmic (N${}^3$LL) accuracy. The resummed results are consistently matched to fixed-order calculations up to $\mathcal{O}({\alpha }_S^3)$. Our resummation formalism also incorporates dominant heavy-quark mass effects and models non-perturbative power corrections by means of an analytic dispersive approach. A simultaneous fit yields an excellent description of experimental data across all energies, enabling a precise determination of the strong coupling, ${\alpha }_S(m_Z^2)=0.119\pm 0.002$, as well as the non-perturbative parameters, including those characterizing the Collins--Soper evolution kernel. Our analysis includes, for the first time in a global fit, datasets from the ALEPH and AMY collaborations.

    hep-phhep-exhep-latJHEP(2026)·4 citations
26. 26*

    Formation and Decay of Oscillons in Einstein-Cartan Higgs Inflation

    Javier Rubio🇪🇸

    We review recent progress in the understanding of the preheating stage of Higgs inflation formulated within the Einstein-Cartan framework of gravity. This setup smoothly interpolates between the metric and Palatini formulations of the theory, leading to a distinctive phenomenology in an intermediate regime. Following the end of inflation, the Higgs field undergoes a non-trivial out-of-equilibrium evolution driven by tachyonic instabilities and nonlinear self-interactions, which fragment the inflaton condensate and give rise to well-localized oscillon configurations. While early studies suggested the formation of long-lived oscillons and the possibility of an extended matter-dominated phase, more recent analyses show that self-interactions at small field values render these objects transient, eventually triggering their decay and the onset of radiation domination. We discuss the implications of this dynamics for the thermal history of the Universe, the inflationary observables, and the generation of stochastic gravitational waves.

    hep-phastro-ph.COgr-qcPoS(2026)·2 citations
27. 27*

    Toward universal coalescence models for antideuteron production

    Mattia di Mauro🇮🇹 · Jordan Koechler🇮🇹 · Lorenzo Stefanuto🇮🇹 · Francesca Bellini🇮🇹 · Fiorenza Donato🇮🇹 · Nicolao Fornengo🇮🇹

    Cosmic-ray (CR) antinuclei, especially antideuteron $\overline{\mathrm{D}}$ and antihelium-3 nuclei ${}^3\overline{\mathrm{He}}$, are among the most promising messengers for indirect dark matter (DM) searches. This is because secondary production in CR interactions with the interstellar medium is strongly suppressed at kinetic energies $K\simeq (0.1-1)$ GeV/$n$, typically one to two orders of magnitude below fluxes expected in standard DM scenarios. From the theoretical side, the formation of $\overline{\mathrm{D}}$ and ${}^3\overline{\mathrm{He}}$ is governed by coalescence, whose dynamics cannot yet be reliably derived from first principles. Phenomenological approaches therefore introduce effective coalescence parameters, possibly dependent on collision energy and production environment (hadronic versus electroweak). In this work we show that a common set of physically motivated coalescence models can simultaneously reproduce collider data in two qualitatively different regimes: ALICE measurements of (anti)deuteron production in $pp$ collisions at $\sqrt{s}=(0.9-13)$ TeV and the ALEPH $\overline{\mathrm{D}}$ multiplicity in hadronic $Z$ decays at $\sqrt{s}=m_Z$. We test both simple event-by-event prescriptions based on a relative-momentum cutoff, finding a preferred coalescence scale $p_{\mathrm{coal}}\simeq 0.2$ GeV, and quantum-mechanical models in the Wigner formalism. In the latter, a Gaussian bound-state wavefunction gives a best-fit momentum width, corresponding to $\delta \simeq 1.7$ fm, while a parameter-free implementation using the Argonne $v_{18}$ wavefunction (constrained by proton-neutron scattering data) agrees with ALICE spectra at the $\sim 25\%$ level. Overall, our results support an approximately universal coalescence description across energies and production environments, strengthening the theoretical basis for interpreting upcoming CR antinuclei searches.

    hep-phastro-ph.HEPRD(2026)·2 citations
28. 28*

    Complete UV Resonances of SMEFT Dim-9 Operators for Short-range Neutrinoless Double Beta Decay

    Hao-Lin Li🇨🇳 · Yu-Han Ni🇨🇳 · Ming-Lei Xiao🇨🇳 · Jiang-Hao Yu🇨🇳 · Xiao-Long Zheng🇨🇳

    We present a systematic classification of tree-level ultraviolet (UV) completions for dimension-nine SMEFT operators relevant to short-range neutrinoless double beta decay. Using the SMEFT J-basis framework, we categorize distinct UV completions, including both all-boson and boson-fermion-boson topologies. A primary objective is the identification of minimal UV realizations, defined as the smallest set of genuine heavy degrees of freedom required to generate each operator. Out of the 505 unique mediator combinations identified, 440 are found to be minimal, with 12 cases necessitating only two distinct heavy species. While our findings reproduce the scalar- and fermion-mediated results of Ref.[1], we significantly extend the classification by providing the first comprehensive compilation of 324 minimal UV completions featuring vector resonances -- a category previously unexplored in this context.

    hep-phCommun.Theor.Phys.(2026)·0 citations
29. 29*

    Neutrinos and gamma rays from Seyfert galaxies constrain the properties of coronal turbulence

    Federico Testagrossa🇯🇵 · Damiano F. G. Fiorillo🇮🇹 · Luca Comisso🇺🇸 · Enrico Peretti🇮🇹 · Maria Petropoulou🇬🇷 · Lorenzo Sironi🇺🇸

    The TeV neutrino signal observed by IceCube from the active galactic nucleus (AGN) NGC 1068 can probe its innermost coronal regions. If these neutrinos originate from hadrons accelerated within a magnetized turbulent corona, their intensity and spectrum depend on the turbulent magnetic field strength and turbulence coherence scale. The gamma rays accompanying neutrino production are absorbed in this optically thick environment, in a way that depends sensitively on the size of the corona. By a joint fit of the IceCube and Fermi-LAT observations, we translate the multimessenger signal from NGC 1068 and the tentative signal from NGC 7469 into quantitative constraints on coronal properties. NGC 1068, with a significant TeV neutrino excess, favors a compact, strongly magnetized corona with a large turbulence coherence length relative to the coronal size. NGC 7469, with two $\sim 100$ TeV neutrino events, points instead to a somewhat larger corona with much smaller coherence length and high magnetization, but a very small fraction of energy in non-thermal protons. We obtain the diffuse flux from a population of Seyfert galaxies identical to either NGC 1068 or NGC 7469. Finally, we consider a third scenario, motivated by the spectral break observed in the diffuse neutrino flux at tens of TeV, with coronal properties intermediate between the two point-source-inspired models. To enable detailed comparisons with the IceCube and electromagnetic observations, we release our model predictions in a GitHub repository.

    ↳ astro-ph.HEhep-phApJ(2026)·5 citations
30. 30*

    ${\Xi }_b\to \Xi$ form factors from lattice QCD and Standard-Model predictions for ${\Xi }_b\to \Xi {\mu }^{+}{\mu }^{-}$ and ${\Xi }_b\to \Xi \gamma$ decays

    Callum Farrell🇺🇸 · Stefan Meinel🇺🇸

    We present the first lattice QCD determination of the ${\Xi }_b\to \Xi$ vector, axial-vector, and tensor form factors, which are relevant for the theory of rare decays including ${\Xi }_b\to \Xi {\ell }^{+}{\ell }^{-}$ and ${\Xi }_b\to \Xi \gamma$. The calculation is performed with 2+1 flavors of domain-wall fermions at three different lattice spacings and pion masses in the range from approximately 430 to 230 MeV. The bottom quark is implemented using an anisotropic clover action. Three-point functions with a wide range of source-sink separations and model averaging are used to extract the ground-state contributions. We fit the dependence of the form factors on the momentum transfer, the pion mass, and the lattice spacing using modified $z$ expansions that account for subthreshold branch cuts, and apply dispersive bounds and asymptotic-behavior constraints to achieve controlled uncertainties in the full semileptonic kinematic region. Using our form factor results, we present Standard-Model predictions for the ${\Xi }_b^{-}\to {\Xi }^{-}\gamma$ and ${\Xi }_b^{-}\to {\Xi }^{-}{\mu }^{+}{\mu }^{-}$ branching fractions and two angular observables.

    ↳ hep-lathep-exhep-phPRD(2026)·1 citation
31. 31*

    Doubly Bottom and Bottom-Strange Tetraquarks in the Isoscalar Channel

    Bhabani Sankar Tripathy🇮🇳 · Nilmani Mathur🇮🇳 · M.Padmanath🇮🇳

    We present our recent investigation on doubly bottom and bottom-strange tetraquarks in the isoscalar channel in search of a possible tetraquark bound state. The calculations are performed on four ensembles with dynamical quark fields up to the charm quark generated by the MILC Collaboration with various lattice spacings. Two volumes have been used to account for finite volume effects. Overlap action has been employed to calculate light and strange quark propagators and NRQCD formulation is utilized for heavy bottom quarks. Finite volume energy has been calculated using the variational method followed by rigorous scattering amplitude analysis à la Lüscher. We find strong evidence for a deeply bound state in the doubly bottom tetraquark channel, but no conclusive evidence for the existence of a bottom-strange tetraquark.

    ↳ hep-lathep-exhep-phPoS(2026)·1 citation
32. 32*

    Jet flavor tagging with Particle Transformer for Higgs factories

    Taikan Suehara🇯🇵 · Takahiro Kawahara🇯🇵 · Tomohiko Tanabe🇯🇵 · Risako Tagami🇯🇵

    We study the performance of the Particle Transformer (ParT) for jet flavor tagging using ILD full simulation events (1M jets) as well as fast simulation samples (10M and 1M jets). We perform 3-category ($b/c/d$), 6-category ($b/c/d/u/s/g$), and 11-category trainings (including quark--antiquark separation), incorporating multivariate hadron particle identification information from $dE/dx$ and time-of-flight. For $b$/$c$ tagging, we observe a factor of 5--10 improvement over previous BDT-based taggers, and we obtain reasonable performance for strange tagging and quark/antiquark separation. The 10M-jet fast simulation study indicates that further gains are possible with higher training statistics.

    ↳ physics.data-anhep-exhep-phEur.Phys.J.Plus(2026)·0 citations
33. 33*

    G objects as Primordial Black Hole-Neutron Star Remnants: Population Modeling and Multi-Wavelength Observables

    David Morales-Zapien · Stefano Profumo🇺🇸

    The nature of the so-called G objects orbiting the Galactic Center remains unresolved. These sources exhibit compact Br$\gamma$ emission, extreme infrared colors, and remarkable dynamical stability through close passages to the central supermassive black hole, challenging conventional interpretations as stars or unbound gas clouds. We investigate the hypothesis that G objects are the remnants of neutron stars that have been converted into low-mass black holes through the capture of primordial black holes, a viable dark-matter candidate. We construct a population-level framework linking the abundance and spatial distribution of these remnants to the neutron-star population, the inner dark-matter density profile, and the primordial black-hole mass and abundance. Within this framework, the observed G-object population and the long-standing deficit of ordinary radio pulsars in the Galactic Center emerge as complementary consequences of the same conversion process. We further identify a suite of observational signatures-across infrared, radio, X-ray, and microlensing channels-that render this scenario empirically testable and distinguishable from stellar-envelope models. Our results show that G objects can act as sensitive probes of compact-object capture physics and of dark matter on sub-galactic scales.

    ↳ astro-ph.HEastro-ph.GAhep-ph0 citations
34. 34*

    Black hole superradiance in Poincaré gauge theory

    Sebastian Bahamonde🇰🇷 · Jorge Gigante Valcarcel🇰🇷

    We investigate the phenomenon of black hole superradiance in the presence of torsion within the framework of Poincaré gauge theory. In particular, in contrast to the classical approach of General Relativity, we show that the inclusion of torsion in the space-time geometry enables the energy extraction from rotating black holes by Dirac fermions via chiral asymmetry, while preserving the Pauli exclusion principle.

    ↳ gr-qcastro-ph.HEhep-phhep-th1 citation
35. 35*

    Spectral reconstruction techniques, their shortcomings and relevance to the electric conductivity coefficient

    C. Andratschke🇩🇪 · B. B. Brandt🇩🇪 · E. Garnacho-Velasco🇩🇪 · L. Pannullo🇩🇪 · S. Singh🇩🇪 · A. Dean M. Valois🇪🇸

    Spectral reconstruction is a well studied numerically ill-posed problem which arises due to the relation of the Euclidean correlator to the spectral function via an inhomogeneous Fredholm equation of the first kind. Several different methods are on the market to resolve this issue, each taking different approaches and assumptions. In this proceedings we focus on implementing and testing a machine learning framework for spectral reconstruction, as well as implementing a novel method of estimating the behavior of the spectral function in the vicinity of vanishing frequency, which we denote as multipoint method, and compare these methods to well established spectral reconstruction techniques from the literature using mock data. As a physics application, we apply the reconstruction techniques to quenched lattice data for the correlation function in the vector channel at non-zero external magnetic field to extract the spectral function and the electric conductivity through its behaviour at vanishing frequency via a Kubo formula.

    ↳ hep-lathep-phPoS(2026)·2 citations
36. 36*

    Quasinormal Modes of Extremal Reissner-Nordstrom Black Holes via Seiberg-Witten Quantization

    Yi-Rong Wang🇨🇳 · Peng Yang🇨🇳 · Kilar Zhang🇨🇳

    We study the scalar perturbations of asymptotically flat extremal Reissner-Nordström black holes via the quantum Seiberg-Witten geometry of $\mathcal{N}=2$ SU(2) gauge theory with $N_f=2$ flavors. The radial master equation, governed by a double confluent Heun equation, is exactly mapped to the quantum Seiberg-Witten curve, providing an exact quantization condition derived from the non-perturbative Nekrasov-Shatashvili free energy. Analytically, this exact dictionary unveils precise gauge-theoretic interpretations for critical physical thresholds, demonstrating that the superradiance and mass decoupling limits naturally reduce the master equation to the Whittaker equation and the reduced doubly confluent Heun equation (the latter corresponds to the SW geometry of the $\mathcal{N}=2$ SU(2) gauge theory with $N_f=1$), respectively. At the strict extremal limit, the coalescence of horizons induces a topological singularity that complicates the spectral analysis. By accommodating this irregular singularity, our geometric framework resolves the singularity coalescence and enables the extraction of the discrete global quasinormal mode. As our main contribution, we provide the first non-perturbative evaluation of the quasinormal modes spectrum for simultaneously charged and massive scalar fields directly at strict extremity. Furthermore, our analytical results reproduce numerical benchmarks for both neutral and charged massless probes, and naturally capture quasi-resonance behaviors.

    ↳ hep-thgr-qchep-phmath-ph+1JHEP(2026)·2 citations
37. 37*

    Perturbative approach to the infrared gluon propagator in the maximal Abelian gauge

    D. M. van Egmond🇧🇷 · L. C. Ferreira🇧🇷 · A. D. Pereira🇧🇷 · G. Peruzzo🇧🇷 · S. P. Sorella🇧🇷

    The inclusion of a mass-like term for the gluon in Yang-Mills theories quantized in the Landau gauge has proven to be an effective way of reproducing lattice results for gauge-fixed correlation functions within perturbative computations. Since those quantities are gauge dependent, it is natural to question how general this prescription is for describing the infrared behavior of gluon and Faddeev-Popov ghost propagators in different gauges. In this work, we provide a systematic investigation of this issue in the maximal Abelian gauge, which cannot be deformed into the Landau gauge and has been investigated in gauge-fixed lattice simulations. We compute the one-loop non-Abelian and diagonal gluon propagators and perform fits to lattice data in the case of $SU(2)$. Our results show that the transverse component of the non-Abelian gluon propagator as well as the diagonal gluon propagator, are in good agreement with lattice data in the infrared.

    ↳ hep-thhep-lathep-phPRD(2026)·1 citation
38. 38*

    Confinement without symmetry breaking in chiral gauge theories

    Haolin Li🇨🇳 · Álvaro Pastor-Gutiérrez🇯🇵 · Shahram Vatani🇧🇪

    The infrared structure of gauge theories with chiral fermions remains largely unexplored. In this work we investigate the Bars-Yankielowicz class using the functional renormalisation group, building on recent developments in gauge-fermion systems that provide clear criteria for confinement and dynamical symmetry breaking. We show that two distinct phases arise: one exhibiting both confinement and symmetry breaking at small numbers of colours, and another characterised by confinement without symmetry breaking in the large-colour limit. The latter realises a novel regime, opening the possibility of exotic spectra and phenomena that can now be studied within a systematic framework.

    ↳ hep-thhep-lathep-ph7 citations
39. 39*

    Four Fermi Theory in Four Dimensions is Renormalisable

    Charlie Cresswell-Hogg🇬🇧 · Daniel F. Litim🇬🇧

    We demonstrate the renormalisability of quantum field theories in four dimensions with elementary self-interacting Dirac fermions and to leading order in the limit of many fermion flavours $N_{\mathrm{f}}$. Starting from the underlying divergence structure and using Gross-Neveu-type interactions as a template, we explain why extended four-fermion theories including higher-derivative interactions are well-defined, renormalisable, and predictive with only a few free parameters. We also provide the exact large-$N_{\mathrm{f}}$ leading beta functions of couplings and discuss quantum scaling dimensions, universality, $1/N_{\mathrm{f}}$ corrections, and extensions to other types of four fermion interactions. Implications for effective theory and model building are indicated.

    ↳ hep-thhep-lathep-ph0 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.