Mon·Jun 1, 2026Monday·June 1, 2026

1. 01*

   Factorizing quarkonium production matrix elements using effective field theory

   Marston Copeland🇺🇸 · Ivan Vitev🇺🇸

   We use effective field theory to factorize production matrix elements that appear in quarkonium cross sections in NRQCD. By applying a Hubbard-Stratonovich transformation we show that the soft and ultrasoft sectors of NRQCD can be decoupled from the heavy quark and antiquark fields in a hybrid vNRQCD/pNRQCD Lagrangian at leading order in the velocity power counting. This enables us to separate quarkonium production matrix elements in terms of matrix elements of color-singlet composite fields, which we can write as the wavefunction at the origin, and state independent vacuum correlators of chromo-electric and chromo-magnetic gluon fields. This approach verifies powerful connections between the LDMEs of different S-wave vector quarkonium states, originally derived using pNRQCD. Additionally, we find new operator contributions for the color-octet P-wave mechanism, which satisfy a similar set of relationships. Finally, this approach allows us to factorize the production matrix elements that appear in the transverse momentum dependent factorization framework, known as TMD soft transition functions, in terms of state independent gluon correlators. This work restores some universality for TMD production operators and dramatically improves the predictive power of NRQCD in the TMD framework.

   hep-phhep-thnucl-thJHEP(2026)·6 citations
2. 02*

   Impact of Primordial Black Holes Induced Neutrinos on the Cosmic 21-cm Brightness Temperature

   Prabhav Singh🇮🇳 · Mansi Dhuria🇮🇳 · Gaurav Goswami🇮🇳

   We study the impact of neutrinos emitted from evaporating Primordial Black Holes (PBHs) on the global 21-cm absorption signal during the dark ages and pre-reionization epochs. PBHs emit neutrinos over a wide energy range through Hawking evaporation. We investigate the possibility that radiative scattering between these neutrinos and the Cosmic Neutrino Background (C$\nu$B) generates secondary photons, leading to additional heating of the neutral hydrogen gas. This modifies the thermal history of the intergalactic medium and increases the global 21-cm brightness temperature relative to the standard cosmological prediction. Using the absorption feature at redshift $z\simeq 17$, we derive new constraints on the PBH fraction for PBH masses in the range $10^{15}\mathrm{g}\lesssim m_{\mathrm{BH},0}\lesssim 10^{25}\mathrm{g}$. We further use existing PBH limits to constrain neutrino self-interaction couplings over a broad range of mediator masses. Our analysis complements previous studies that focused on direct photon injection from PBH evaporation and highlights the importance of neutrino-induced effects within a multimessenger framework for probing PBHs and beyond-standard-model neutrino interactions.

   hep-ph1 citation
3. 03*

   Generative Models and Statistical Validation

   Sascha Diefenbacher🇺🇸 · Sofia Palacios Schweitzer🇩🇪 · Gregor Kasieczka🇩🇪

   Generative machine learning has become an essential tool in theoretical and experimental physics, especially in the context of fast surrogates and density estimators. In this work, we first introduce the underlying framework of modern generative networks and then discuss challenges in quantifying their accuracy, precision, and statistical power.

   hep-phcs.LGphysics.data-an3 citations
4. 04*

   Canonical statistical hadronization with local baryon conservation for higher-order cumulants

   Mario Ciacco🇮🇹 · Sourav Kundu🇨🇭 · Volodymyr A. Kuznietsov🇺🇸 · Maximiliano Puccio🇨🇭 · Volodymyr Vovchenko🇺🇸

   We study higher-order cumulants of the conserved baryon number at the LHC within the canonical ensemble with local baryon conservation. We generalize the density correlations approach of [Phys. Rev. C 110, L061902 (2024)] to incorporate the effect of Gaussian local conservation in spatial rapidity space in cumulants up to 6th order. Gaussian local conservation improves upon the commonly employed $V_c$ approach, yielding comparable predictions at midrapidity, but marked differences for larger rapidity acceptances. Our coordinate-space results are in exact agreement with the diffusion master equation approach for all cumulant ratios up to ${\kappa }_6/{\kappa }_2$. Using the blast-wave model to apply kinematic cuts, we obtain predictions for net-proton cumulants in O--O and Pb--Pb collisions at the LHC that establish an ideal hadron gas baseline. We find that local baryon conservation alone can drive ${\kappa }_6/{\kappa }_2$ to small or even negative values in restricted acceptance, a behavior often associated with chiral criticality. The conservation baseline must therefore be carefully accounted for when interpreting upcoming LHC measurements.

   hep-phnucl-th2 citations
5. 05*

   Functional renormalization group study of the jet quenching parameter near the QCD critical end point

   Yi-zhen Huang🇨🇳 · Shi Yin🇩🇪 · Sheng-nan Han🇨🇳 · Jing Wu🇨🇳 · Feng Li🇨🇳 · Wei-jie Fu🇨🇳

   We investigate the jet quenching parameter $\hat{q}$ in the QCD phase diagram within a QCD-assisted low-energy effective theory using the functional renormalization group (fRG). Following the formalism that relates $\hat{q}$ to the spectral functions of the chiral order-parameter field, we compute the $\sigma$ and $\pi$ meson contributions to $\hat{q}$ at finite temperature and baryon chemical potential from analytically continued mesonic two-point functions. We find that $\hat{q}$ receives appreciable contributions mainly above the chiral phase boundary and exhibits a pronounced enhancement at large baryon chemical potential as the chiral crossover sharpens toward the critical end point (CEP), a behavior consistent with the picture of partonic critical opalescence (PCO), a pronounced enhancement of jet transverse momentum broadening induced by the critical $\sigma$ field fluctuations.

   hep-phnucl-th1 citation
6. 06*

   Moderate-to-Large-$x$ Gluon Helicity from $J/\psi$ Production at $\sqrt{s}=27\mathrm{GeV}$

   Shubham Sharma🇷🇺 · Alexey Aparin🇷🇺 · Satyajit Puhan🇹🇼 · Narinder Kumar🇮🇳 · Harleen Dahiya🇮🇳

   We present a feasibility study of the longitudinal double-spin asymmetry $A_{LL}$ in inclusive $J/\psi$ production in polarized proton-proton collisions at $\sqrt{s}\approx 27\mathrm{GeV}$ at the Spin Physics Detector (SPD) of the Nuclotron-based Ion Collider fAcility (NICA). At these moderate energies, $J/\psi$ production is dominated by gluon-gluon fusion, probing gluon momentum fractions $x\approx 0.1$-$0.2$ at central rapidity and highly asymmetric configurations at forward rapidity, where one parton can reach $x\approx 0.5$-$0.9$. This provides direct sensitivity to the poorly constrained moderate- to large-$x$ region of the gluon helicity distribution $\Delta g(x)$. We estimate $A_{LL}$ as a function of transverse momentum and rapidity using polarized parton distribution functions, focusing on the underlying partonic spin asymmetry. Nonperturbative long-distance effects are treated in a simplified manner and largely cancel in the asymmetry, enabling a direct assessment of gluon polarization sensitivity. We find asymmetries reaching $|A_{LL}|\approx 0.09$ at $p_T=3\mathrm{GeV}$, with enhanced sensitivity at forward rapidity. The dominant theoretical uncertainty arises from polarized parton distribution functions. These results demonstrate that inclusive $J/\psi$ measurements at SPD/NICA provide a sensitive and complementary probe of gluon polarization at moderate and large $x$, extending constraints from RHIC into a kinematic regime not directly accessible to the EIC.

   hep-ph0 citations
7. 07*

   Searching for Lepton Flavor Violating decays of the Higgs Boson into $\mu \tau$, $e\tau$, and $e\mu$ final states at FCC-ee

   P. Sriling🇹🇭 · N. Srimanobhas🇹🇭 · P. Uttayarat🇹🇭 · R. Uttho🇹🇭 · V. Wachirapusitanand🇹🇭

   We investigate the projected sensitivity of the FCC-ee in probing the LFV decay of the 125 GeV Higgs boson, $h\to \mu \tau$, $h\to e\tau$, and $h\to e\mu$ at center-of-mass energy of 240 GeV with an integrated luminosity of 5 ab${}^{-1}$. With the clean multi-lepton final states, we consider the Higgs production modes that contribute to $e^{+}{e}^{-}\to \ell \ell h$, in particular, the Higgs-strahlung and the vector boson fusion production channels. The 95\% CL upper limits on branching ratio are found to be $5.92\times 10^{-4}$, $6.27\times 10^{-4}$, and $7.48\times 10^{-5}$ for the channels $h\to \mu \tau$, $h\to e\tau$, and $h\to e\mu$, respectively. In addition, we also consider the LFV decay of a new CP-even Higgs boson with mass in the range of $110-200$ GeV. The projected FCC-ee sensitivities are then compared to those from low energy searches for $\ell \to {\ell }^{\prime }\gamma$ decay. We find that the FCC-ee sensitivity for the LFV decays of the Higgs in the $e-\tau$ and $\mu -\tau$ channels is superior to the low-energy constraints. However, in the $e-\mu$ case, the low energy search offers stronger constraints.

   hep-phhep-ex0 citations
8. 08*

   Geometric Phases as Probes of Dark Sectors

   Antonio Capolupo🇮🇹 · Gabriele Pisacane🇮🇹 · Raoul Serao🇮🇹

   We review recent interferometric schemes designed to probe physics beyond the Standard Model through the detection of geometric phases. We discuss how interactions with hidden-sector degrees of freedom, such as axion-like particles and mirror-matter candidates, can induce potentially observable phase shifts in ordinary fermion systems.

   hep-ph0 citations
9. 09*

   Nuclear matter and proton parton distributions in a light-front Hamiltonian framework

   Xiaoyi Wu🇨🇳 · Sreeraj Nair🇨🇳 · Satvir Kaur🇨🇳 · Chandan Mondal🇨🇳 · Jiangshan Lan🇨🇳 · Xingbo Zhao🇨🇳 · J. P. B. C. de Melo🇧🇷 · Tobias Frederico🇧🇷

   We develop a light-front Hamiltonian formulation of symmetric nuclear matter within the quark-meson coupling model, using Basis Light-Front Quantization to solve the in-medium nucleon eigenvalue problem. The Hamiltonian incorporates confinement in the valence sector and is truncated to include up to one dynamical gluon. Medium effects are introduced via scalar and vector mean fields, yielding a self-consistent, density-dependent effective quark mass and modified nucleon structure. The resulting energy per nucleon, pressure, and incompressibility are consistent with empirical constraints at the saturation point. At nuclear saturation density, the gluon probability in the nucleon wave function increases slightly, while the valence probability and quark momentum fraction decrease. The unpolarized quark and gluon distributions show a noticeable enhancement at large momentum fraction ($x\gtrsim 0.4$), illustrated at an evolved scale of $Q^2=10{\mathrm{GeV}}^2$.

   hep-ph0 citations
10. 10*

    Radiative Corrections to Elastic Lepton-Proton Scattering with Focus on Two-Photon-Exchange Diagrams

    Daniel Crowe🇺🇸 · Syed Mehedi Hasan🇩🇪 · Doreen Wackeroth🇺🇸

    Lepton (electron and muon) scattering experiments are excellent tools to gain insight into the nucleon structure. Elastic electron-proton scattering probes the spatial distribution of charge and magnetization inside the proton, and comparing electron-proton and muon-proton scattering data tests lepton universality. The availability of a plethora of scattering data with increased precision and observed discrepancies such as the proton form factor puzzle and the proton radius puzzle motivated a renewed effort to improve the theoretical framework. Realizing that the one-photon-exchange approximation (OPE), i.e. the Born approximation, is not sufficient, radiative corrections in QED, especially the two-photon-exchange (TPE) diagrams, are under investigation. The TPE diagrams are of special interest among the radiative corrections, since they depend on the proton structure. In this work, we present a complete calculation of QED radiative corrections to elastic electron-proton and muon-proton scattering at next-to-leading order, taking into account loop-momentum-dependent form factors. In the discussion of their numerical impact on lepton-proton scattering cross sections, we pay special attention to the TPE diagrams and compare them with existing theoretical predictions and lepton-proton scattering data.

    hep-phnucl-th1 citation
11. 11*

    A unified study of the \(B_c\) meson: from spectrum and form factors to weak and radiative decays

    Vikas Patel🇮🇳 · Chetan Lodha🇮🇳 · Raghav Chaturvedi🇮🇳 · A. K. Rai🇮🇳

    The $B_c$ meson constitutes a unique system for investigating heavy-hadron dynamics, since it exhibits quarkonium-like bound-state structure while decaying predominantly through weak interactions. In this work, we present a unified study of $B_c$-meson spectroscopy, decay constants, weak decays, radiative transitions, and Regge trajectories within a single framework. The mass spectrum is computed in a screened potential model including relativistic kinetic-energy corrections and spin-dependent interactions, from which we obtain both spin-averaged and spin-resolved states together with the corresponding pseudoscalar and vector decay constants. Using these spectroscopic inputs, we then analyze weak decays within a mass-updated three-point QCD sum-rule framework for transitions to $S$-, $P$-, and $D$-wave charmonium states, as well as to final states containing charmonium and $D_{(s)}^{(\ast )}$ mesons. In this part of the analysis, the hadronic thresholds, Borel-window prescriptions, Lorentz decompositions, and decay-width expressions of the underlying sum-rule formulations are retained, while the heavy-quark masses are updated to $m_c=1.48\mathrm{GeV}$ and $m_b=4.90\mathrm{GeV}$, leading to a controlled refit of the overall normalization rather than a full rederivation of all perturbative and condensate contributions. We further investigate purely leptonic decay widths and radiative $E1$ and $M1$ transitions, and examine the Regge behavior of the resulting spectrum. The present study therefore provides a coherent description of the $B_c$ meson in which the spectroscopic wave functions determine the short-distance couplings that enter both weak and electromagnetic observables, while the Regge analysis serves as a complementary global consistency test of the same dynamical picture.

    hep-phEPJC(2026)·3 citations
12. 12*

    CoLoRFulNNLO for color-singlet processes: An update on NNLOCAL

    S. Van Thurenhout🇭🇺 · V. Del Duca🇮🇹 · C. Duhr🇩🇪 · L. Fekésházy🇩🇪 · F. Guadagni🇨🇭 · P. Mukherjee🇩🇪 · G. Somogyi🇭🇺 · F. Tramontano🇮🇹

    We give an update on the status of NNLOCAL, a parton-level Monte Carlo program implementing the extension of the completely local subtraction scheme CoLoRFulNNLO to color-singlet production in hadron-hadron collisions. The construction of the counterterms in our scheme is generic, being based on the standard IR factorization formulae of QCD. Furthermore, the integration of the counterterms over the phase space of unresolved emissions is performed fully analytically, allowing for good control of the numerical stability of our predictions. We validate our method by computing NNLO corrections to fully differential cross sections for the LHC.

    hep-phhep-th0 citations
13. 13*

    Neutrino helicity oscillations in astrophysical environments: a many-body approach

    Yiheng Xu🇨🇳 · Julien Froustey🇪🇸 · George M. Fuller🇺🇸 · Lukáš Gráf🇨🇿 · Amol V. Patwardhan🇺🇸

    Neutrino rest mass enables left-handed states to "flip" to right-handed states and vice versa. In-medium effects can enhance the probability for such spin-flip. We demonstrate that a full many-body calculation of this process in neutrino-dense environments can lead to spin-flip probabilities that exceed by orders of magnitude those calculated with mean-field treatments. We study simple configurations with a few neutrinos in well-defined momentum states, for which we show that the helicity conversion enhancement is connected to many-body momentum exchange. Such an effect would therefore be missed in a calculation that considers only forward processes. We speculate on the potential astrophysical implications of these results and the range of applicability of our calculation and its limitations.

    hep-phastro-ph.HE1 citation
14. 14*

    Thermodynamics of the Isospectral family of holographic vector mesons

    Miguel Angel Martin Contreras🇨🇳 · Saulo Diles🇧🇷 · Alfredo Vega🇨🇱

    We study the thermal behavior of the $\rho$ meson using the isospectral family of the softwall AdS/QCD model. By computing spectral functions at finite temperature and chemical potential for different members of this family, we isolate the effect of the ground-state electromagnetic decay constant $f_1$ on the melting temperature $T_m$ of the $\rho (770)$ meson. A clear monotonic increase of $T_m$ with $f_1$ is found, supporting the interpretation of $f_1$ as a key scale controlling quarkonium dissociation. For excited states, the same qualitative trend appears but is strongly suppressed as the radial quantum number increases. Using the isospectral parameter to fix $f_1$ to its experimental value ($226$ MeV) yields a holographic model whose spectral function gives a melting temperature $T_m=157$ MeV and a smooth crossover from confinement to deconfinement. The thermal mass shows a mild decrease near the critical point, while the width grows monotonically. Our results demonstrate that the isospectral transformation provides a controlled way to adjust ground-state decay constants without altering the mass spectrum, enabling precise studies of medium effects on vector mesons.

    hep-phhep-th2 citations
15. 15*

    Revisiting Unidentified Charged-Hadron Fragmentation Functions with Modern COMPASS SIDIS Multiplicities

    HAPS Collaboration: Maryam Soleymaninia🇮🇷 · Hamzeh Khanpour🇵🇱 · Hubert Spiesberger🇩🇪 · Majid Azizi🇮🇷 · Michael Klasen🇩🇪 · Hadi Hashamipour🇮🇷

    We present \texttt{HAPS-hFF1.0}, a new global QCD analysis of unidentified charged-hadron fragmentation functions (FFs) using single-inclusive electron-positron annihilation (SIA) data together with the modern COMPASS semi-inclusive deep-inelastic scattering (SIDIS) multiplicities. The COMPASS input consists of the 2025 proton-target measurement and the revised isoscalar-target multiplicities provided in the COMPASS addendum 2026. The extraction is performed at both next-to-leading order (NLO) and next-to-next-to-leading order (NNLO), allowing us to study the perturbative stability of the QCD fit and the impact of the updated SIDIS information on the flavor structure of the FFs. We find that the modern COMPASS multiplicities can be consistently described together with the SIA data and provide important charge-separated constraints on the light-quark and antiquark FFs. The comparison between the NLO and NNLO extractions indicates a stable quark-sector determination, while the gluon FF remains less directly constrained in the present SIA+SIDIS analysis. Our results highlight the importance of the modern COMPASS SIDIS multiplicities for precision studies of unidentified charged-hadron fragmentation and for future global FF determinations. The resulting \texttt{HAPS-hFF1.0} replicas are publicly available in standard LHAPDF format.

    hep-phhep-exPRD(2026)·1 citation
16. 16*

    Signals of New Resonances from Di-Lepton Non-Universality in the Bottomonium Mass Region at the Large Hadron Collider

    Connor Houghton🇺🇸 · Amit Lath🇺🇸 · Joseph Reichert🇺🇸 · Scott Thomas🇺🇸

    Universality classes of new physics models featuring narrow boson resonances produced through strongly interacting initial states in proton-proton collisions and with enhanced decays to di-tau final states are classified. Spin-zero scalar or pseudoscalar bosons with chirality-violating fermion couplings can induce potentially significant di-lepton non-universality in the bottomonium mass region, with up to many hundreds of nanobarns of direct production total cross section in proton-proton collisions at the Large Hadron Collider. Conversely, mass suppressed chirality-violating couplings of spin-zero bosons to di-electrons maintain di-lepton universality to a high degree in the same mass region at electron-positron colliders. Simultaneous measurement and comparison of integrated resonant prompt di-electron, di-muon, and di-tau mass spectra at the Large Hadron Collider in the bottomonium mass region could be sensitive to the existence of new boson resonances with enhanced di-tau decays, or likewise bottomonium states with non-Standard Model enhanced di-tau decay modes.

    hep-ph1 citation
17. 17*

    CJ26 Global QCD Analysis with Large-$x$ Jefferson Lab 6 and 12 GeV Data

    Alberto Accardi🇺🇸 · Matteo Cerutti🇫🇷 · Cynthia E. Keppel🇺🇸 · Shujie Li🇺🇸 · J. F. Owens🇺🇸 · Sanghwa Park🇺🇸 · Peter Risse🇺🇸

    We present CJ26, the new CTEQ-JLab global QCD analysis that incorporates for the first time the complete suite of JLab 6 GeV DIS measurements and the first published JLab 12 GeV measurements. Focused on the large-$x$ region, the analysis utilizes the increased $Q^2$ leverage of the 12 GeV data to uniquely disentangle higher-twist effects from off-shell nucleon corrections. This leads to a highly accurate determination of the $n/p$ structure function ratio and the $d/u$ valence quark ratio, with uncertainties reduced by 30-50% and 5-10%, respectively. We highlight the critical role of experimental correlated systematic uncertainties in achieving this precision and provide the resulting NLO PDFs and structure functions in LHAPDF format for general use.

    hep-phhep-exhep-lat4 citations
18. 18*

    Dirac-Phase CP-Violation in the Low-Scale Type-I Seesaw with Three Right-Handed Neutrinos

    Alessandro Granelli🇪🇸 · Juraj Klarić🇳🇱 · S. T. Petcov🇮🇹

    We study the low-scale type-I seesaw with three right-handed neutrinos (i.e. heavy Majorana neutrinos) when the CP-violation arises solely from the low-energy Dirac phase $\delta$ of the Pontecorvo-Maki-Nakagawa-Sakata (PMNS) neutrino mixing matrix and the heavy neutrinos have testable mixings. We derive a CP-conserving and non-real structure of the $3\times 3$ orthogonal matrix entering the Casas-Ibarra parametrisation in terms of two real angles and one single imaginary parameter, ensuring that the only CP-violating phases in the neutrino Yukawa couplings are those of the PMNS matrix. We then focus on the case of CP-violation from $\delta$ alone and discuss the phenomenological implications of this hypothesis. We concentrate on quasi-degenerate heavy Majorana neutrinos with masses within $\sim (0.1-100)\text{GeV}$, as relevant for low-scale leptogenesis. Only certain subregions of the full ternary space defined by the ratios ${\Theta }_e^2:{\Theta }_{\mu }^2:{\Theta }_{\tau }^2$ -- where ${\Theta }_{\alpha }^2$ denotes the squared coupling of the heavy neutrinos to leptons of flavour $\alpha =e,\mu ,\tau$ -- are compatible with Dirac-phase CP-violation while being testable at collider experiments. Our assumption also implies specific forms of the effective Majorana mass parameter that can be tested at neutrinoless double-beta decay searches. Finally, low-scale leptogenesis under this restrictive scenario can still reproduce the observed baryon asymmetry of the Universe (BAU) in the entire testable region of the parameter space. The BAU vanishes in the exact limit of CP-conserving values of the Dirac phase $\delta =0,\pi ,2\pi$, but the observed BAU can be reproduced within the testable region even if $\delta$ deviates from these values by a factor as small as $\mathcal{O}(10^{-5})$, with important implications for ultraviolet completions with approximate CP-symmetry.

    hep-ph0 citations
19. 19*

    Hyperoptimisation algorithm for the next generation of PDF determinations: ensemble regression with an unbiased selection model

    Juan M. Cruz-Martinez🇪🇸 · Tommaso Giani🇮🇹 · Tanjona R. Rabemananjara🇫🇷

    We present a new automated procedure for selecting fitting methodologies in the determination of parton distribution functions (PDFs), based on a hyperoptimisation algorithm using ensemble regression. Building on the k-folding approach previously employed by the NNPDF collaboration, we introduce a systematic strategy to generate ensembles of hyperparameter configurations and define a new k-folding metric that consistently incorporates full PDF uncertainties. The algorithm outputs an ensemble of statistically equivalent fitting methodologies, which are combined to produce a single PDF set whose uncertainties consistently account for hyperparameter variation. We assess the impact of this approach by comparing results obtained with identical data and theoretical inputs but different fitting methodologies, determined using the previous and the new hyperoptimisation procedures. The new method broadly confirms earlier NNPDF results, while yielding moderately larger uncertainties in regions where data provide limited constraints.

    hep-ph2 citations
20. 20*

    Deeply bound dibaryon $d^{\ast }(2380)$ from meson-exchange saturation $\Delta \Delta$ effective field theory

    Prin Sawasdipol🇹🇭 · Chinadanai Bubpatate🇹🇭 · Daris Samart🇹🇭

    We propose an RG-improved effective-field-theory framework for the deeply bound dibaryon $d^{\ast }(2380)$, a $\Delta \Delta$ bound state in the $(J,I)=(3,0)$ ${}^7{S}_3$ channel. Its binding momentum $\gamma \simeq 320$ MeV gives $\gamma /m_{\pi }\simeq 2.3$, indicating the need to re-organize the short-range dynamics beyond a formal pionless EFT. We match the large-$N_c$-constrained pionless contact potential to a meson-exchange-saturated contact interaction in which the $\sigma ,\rho ,\omega$ dynamics are integrated out at the hadronic scale $m_V$, yielding the controlled expansion parameter $\gamma /m_V\simeq 0.42$. Normalizing the contact coupling to the deuteron and substituting the phenomenological CD-Bonn couplings gives $B_{\Delta \Delta }\simeq 96$ MeV. The $\simeq 14\%$ discrepancy from $B_{\exp }=84$ MeV is of the natural size of $\mathcal{O}(1/N_c^2)\simeq 11\%$ corrections to the $NN$ potential, confirming compatibility with a controlled EFT expansion organized around the finite-range hadronic scale. As a result, the observed $d^{\ast }(2380)$ pole emerges from the virtual state to bound state by using the EFT re-organization in this work.

    hep-phnucl-th0 citations
21. 21*

    Isosinglet-isotriplet mixing and the $X(3872)$ lineshape

    Davide Germani🇮🇹 · Benjamin Grinstein🇺🇸

    We investigate the lineshapes of the $X(3872)$ in $B^{+}$ decays production within a framework that incorporates two underlying QCD configurations: a compact isosinglet state $X_S$ and the neutral component of a molecular isotriplet $X_T^0$. The physical signal is interpreted as arising from the mixing of these states, induced by strong isospin breaking. The decay amplitude is constructed in a factorized form, separating short-distance production, non-relativistic propagation and final-state interactions. This setup allows for a unified description of both $D{D}^{\ast }$ and $J/\psi +$ pions final states. We show that the interplay between the two components and their mixing can qualitatively reproduce several nontrivial experimental features. In particular, interference effects can enhance the charged $D{D}^{\ast }$ channel relative to the neutral one despite phase-space suppression, and generate distinctive structures in the $J/\psi {\pi }^{+}{\pi }^{-}$ and $J/\psi {\pi }^{+}{\pi }^{-}{\pi }^0$ lineshapes, including the possibility of strong distortions near threshold.

    hep-ph0 citations
22. 22*

    Statistical imprints of wave-like dark matter on multiply-imaged galaxies in strong cluster lenses from JWST

    Nino Ephremidze🇺🇸 · Daniel Gilman🇺🇸 · Cora Dvorkin🇺🇸

    Wave-like dark matter ($\psi$DM) is an elusive dark matter (DM) candidate. The model, often also called fuzzy or ultralight DM, proposes that DM is an extremely light ($m\sim 10^{-22}$ eV) boson and thereby has a kpc-scale de Broglie wavelength. Hence, interference of DM gives rise to sub-galactic density fluctuations that can be studied with strong gravitational lensing. In this paper, we use the residual power spectrum, ${\mathrm{P}}_{\delta }(k)$, as a probe of $\psi$DM, which quantifies deviations from smooth lensing predictions, measured from multiply-imaged galaxies in strong cluster lenses. The key idea is that imprinted in these deviations are lensing distortions from DM substructure, which can be harnessed statistically to distinguish among DM theories. We simulate JWST-quality mock observations of strong gravitational lensing in galaxy clusters, modeling line-of-sight DM substructure within $\psi$DM and the standard cold dark matter (CDM) paradigms. Using mock deep observations ($\sim$ 20 hours), we find that ${\mathrm{P}}_{\delta }(k)$ is sensitive to both $\psi$DM particle mass and fluctuation amplitude, and can distinguish $\psi$DM fluctuations from CDM subhalos. We demonstrate that ${\mathrm{P}}_{\delta }(k)$ can be measured directly from data by modeling the smooth lensing with a local Curved Arc Basis formalism. With realistic modeling systematics, we find a statistically significant separation between $\psi$DM and CDM across $1\lesssim k\lesssim 11{\mathrm{kpc}}^{-1}$ -- offering an independent probe of the wave-like nature of DM complementary to existing constraints.

    ↳ astro-ph.COhep-ph1 citation
23. 23*

    Matter influence on large-scale scalar dynamics

    Philippe Brax🇫🇷

    Local structures in the Universe can influence the dynamics of light scalar fields when coupled to matter. We focus on light test fields evolving in matter modelled as a stochastic source. We describe the effective field theory for light scalars on large scales after integrating out the short distance dynamics. This is most conveniently performed in the Schwinger-Keldysh formalism where we find that the large distance theory involves a stochastic noise corresponding to the exchanges between short and large scales, and new interactions which can affect the time evolution of light scalars. We exemplify this back-reaction when the coupling between matter and scalars is small leading to corrections to the Klein-Gordon equation of the light scalars on large scales. In particular, the resulting corrections to the scalar potential could lead to effects akin to dynamical dark energy. We also consider the situation where all the substructures of the Universe are screened leading to the suppression of large scale dynamics and a cosmic Meissner effect. This highlights the potentially relevant effects of small scale structures on the cosmological dynamics of light scalar fields.

    ↳ astro-ph.COhep-ph0 citations
24. 24*

    Seeded bubble nucleation on the lattice

    Simone Blasi🇩🇪 · Andreas Ekstedt🇸🇪 · Jaakko Hällfors🇫🇮 · Kari Rummukainen🇫🇮

    We provide the first non-perturbative lattice determination of the bubble nucleation rate as seeded by topological defects during a first order phase transition. Our case of study is the cubic anisotropy model, which can mimic the Higgs-plus-singlet setup for the electroweak theory, in $d=2+1$ spacetime dimensions, where bubbles are seeded by (line-like) domain walls. We compare the nucleation rate from the lattice with the semi-classical prediction based on the effective field theory living on the domain walls, including for the first time the fluctuation determinant away from spherical symmetry. Our results show very good agreement across all the considered parameter space.

    ↳ hep-lathep-ph0 citations
25. 25*

    Time-reversed stochastic inflation in the quantum well

    Chiara Animali🇧🇪 · Baptiste Blachier🇧🇪 · Nanoka Okada🇯🇵 · Christophe Ringeval🇧🇪 · Tomo Takahashi🇯🇵 · Koki Tokeshi🇫🇷

    Time-reversed stochastic inflation solves the stochastic evolution of the inflationary universe backward in time, by counting the number of e-folds from the end of quantum diffusion towards some initial state. The point of view of observers attached to the end-of-inflation hypersurface is thus enforced. In this work, we exactly solve time-reversed stochastic inflation in a flat and bounded potential, the so-called quantum well. At given lifetime, the field behaviour is found to be either indistinguishable from the one obtained in a semi-infinite flat potential, or, subject to enhanced stochasticity where any memory of the initial state is erased. The derived distribution of curvature perturbations reduces to the semi-infinite result for small fluctuations while it develops exponential tails for the large ones. Such tails arise for both positive and negative values, and decay twice as fast as the one obtained in the standard forward stochastic inflation. These differences may have important consequences for tail-sensitive phenomena, such as primordial black hole formation.

    ↳ astro-ph.COgr-qchep-phhep-th3 citations
26. 26*

    Gravothermal Collapse: Robust Against Baryonic Feedback

    Demao Kong🇺🇸 · Hai-Bo Yu🇺🇸

    We perform a stress test of gravothermal collapse in self-interacting dark matter (SIDM) halos under baryonic feedback using a semi-analytical oscillating-potential model in controlled N-body simulations. For high-concentration halos, where the SIDM thermalization timescale is short, gravothermal collapse is only mildly delayed and never stalled, even under extremely strong feedback. In contrast, the collapse of a median-concentration halo can be significantly delayed, but it resumes once feedback ceases. The final density profile of such halos depends sensitively on the episodic feedback history, producing a broad diversity in central densities. These results strengthen the interpretation of dense compact perturbers identified in recent strong-lensing observations as core-collapsed SIDM halos.

    ↳ astro-ph.COastro-ph.GAhep-ph3 citations
27. 27*

    Accessing Exotic Hadronic States via Charmed-Meson Femtoscopy in Relativistic Heavy-Ion Collisions

    Jiaxing Zhao🇩🇪 · Taesoo Song🇩🇪 · Elena Bratkovskaya🇩🇪 · Joerg Aichelin🇫🇷

    The two-particle correlation function measured in femtoscopic analyses provides access to the interaction potentials between emitted particles. This offers a unique opportunity to investigate interactions among charmed mesons and to explore the nature of possible exotic hadronic states. In this Letter, we study femtoscopic correlations of various charmed-meson pairs in relativistic heavy-ion collisions. The dynamical evolution of the system and charm hadron production are described within the Parton-Hadron-String Dynamics (PHSD) transport approach, while the correlation functions are computed using the Correlation Analysis Tool using the Schrödinger equation (CATS). We demonstrate that heavy-ion collisions provide a significantly more favorable environment than $pp$ collisions for accessing charmed meson femtoscopic correlations. This arises from enhanced charm-quark production, reduced relative momenta due to in-medium energy loss, and a strong suppression of initial-state correlations. Our results indicate that femtoscopic measurements in heavy-ion collisions offer a sensitive probe of charmed meson interactions and possible hadronic molecular states.

    ↳ nucl-thhep-ph0 citations
28. 28*

    Gravitational Waves from hybrid defects as probe of Flavor symmetry breaking: Machine-Learning Approach

    Anish Ghoshal🇮🇹 · Ilia Gogoladze🇺🇸 · Amit Tiwari🇺🇸

    We present a novel possibility that a network of domain walls bounded by cosmic strings generates a stochastic gravitational wave background (SWGB) signal originating from the spontaneous breaking of a gauged $U(1{)}_F$ flavor symmetry and the subsequent breaking of discrete $Z_2$ symmetry that accommodates dark matter. The gravitational wave (GW) spectrum produced by the string-bounded-wall network can be detected for high $U(1{)}_F$ breaking scales in forthcoming GW detectors including LISA, ET and SKA. The GW signal exhibits a distinctive frequency slope, in the infrared, compared to the standard cosmic-string case, in the frequency range between micro-hertz and hertz. We develop a possible strategy to distinguish and characterize GW spectrum of the hybrid defect from from other defects, such as stable cosmic strings, via employing the exact calculation with a machine-learning surrogate, based on a multilayer perceptron (MLP), trained on spectra obtained from the full numerical treatment. This is then used for rapid inference in the detector-specific signal-to-noise ratio (SNR) computation which also makes the process fast and efficient. We also discuss some possible complementarity between GW searches and Flavor observables in the laboratory.

    ↳ astro-ph.COhep-phhep-thJHEP(2026)·1 citation
29. 29*

    Eigenvalue formulation of Stochastic Inflation and application to large perturbation generating inflationary features

    Swagat S. Mishra🇬🇧 · Edmund J. Copeland🇬🇧 · Anne M. Green🇬🇧

    Stochastic inflation is a powerful technique for calculating the probability distribution function (PDF) of large inflationary perturbations, which may collapse to form Primordial Black Holes. The PDF, $P(\mathcal{N})$, of the stochastic number of e-folds, $\mathcal{N}$, satisfies an adjoint Fokker-Planck Equation. We develop a new self-contained eigenvalue technique which can be used to determine $P(\mathcal{N})$. First we apply this method to the simple case of quantum diffusion along a flat potential without any classical drift. We recover the expression for the PDF that has previously been found using characteristic functions, with an exponential tail, and a power-law behaviour, $P(\mathcal{N})\propto {\mathcal{N}}^{-3/2}$, in the intermediate regime between the peak and the tail of the PDF. Finally we apply the method to constant drift inflation, in the narrow- and broad-well limits. In the narrow-well limit, there is an analytic solution and the PDF is similar to the drift-free case, with a mildly suppressed tail. In the broad-well limit, determining the full set of eigenvalues and eigenfunctions requires a piecewise construction of the spectrum, and the broad-well PDF is qualitatively different, with an enhanced peak and a strongly suppressed tail.

    ↳ astro-ph.COgr-qchep-phhep-th+22 citations
30. 30*

    An AI-ready, Polarized Electron-Positron Collision Dataset

    Chi Lung Cheng🇺🇸 · Simon Corrodi🇺🇸 · T. J. Hobbs🇺🇸 · Alaettin Serhan Mete🇺🇸 · Benjamin Nachman🇺🇸

    We present a modernized, AI-ready release of reconstructed data from the SLD experiment at the SLAC Linear Collider (SLC). The dataset comprises approximately 660{,}000 reconstructed events collected at $\sqrt{s}\approx 91.2$~GeV with a highly polarized electron beam from 1996--1998. The data have been translated from legacy formats into modern, widely-used file formats with the help of AI agents. The release also includes a corpus of newly digitized SLD internal documentation. We describe the contents of both components and provide physics validation demonstrations along with illustrations of their utility for physics and machine learning research in particle physics.

    ↳ hep-exhep-ph3 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.