Fri·Dec 26, 2025Friday·December 26, 2025

1. 01*

   Probing gluon saturation with forward di-hadron correlations in proton-nucleus collisions

   Paul Caucal🇫🇷 · Zhong-Bo Kang🇺🇸 · Piotr Korcyl🇵🇱 · Farid Salazar🇺🇸 · Björn Schenke🇺🇸 · Tomasz Stebel🇵🇱 · Raju Venugopalan🇺🇸 · Wenbin Zhao🇨🇳

   We present a detailed numerical investigation of semi-inclusive forward di-hadron production in proton-nucleus collisions employing the Color Glass Condensate effective theory. We focus on the regime where di-hadrons are produced nearly back-to-back in the transverse plane, thereby justifying a transverse-momentum-dependent factorization approach in terms of small-$x$ gluon distributions. Our computation integrates several key elements: i) non-linear rapidity evolution via the Balitsky-Kovchegov equation with running coupling, ii) both perturbative and non-perturbative Sudakov resummation, and iii) a phenomenologically constrained model for the initial conditions for small-$x$ gluon distributions. We compare this phenomenological framework to experimental data from the STAR Collaboration on azimuthal correlations in forward di-pion production in both proton-proton and proton-gold collisions. We analyze the systematic theoretical uncertainties associated with the saturation scales of nuclei at the initial scale for rapidity evolution and with those associated with the hadronization process. Finally, we make predictions for the kinematics anticipated to be covered by the ALICE Forward Calorimeter (FoCal) upgrade at the Large Hadron Collider.

   hep-phnucl-exnucl-thPLB(2026)·15 citations
2. 02*

   Probing Internal Conversion and Dark-Matter-Induced De-excitation of 180mTa with a gamma-ray TES Array

   A. Gando🇯🇵 · K. Ichimura🇯🇵 · K. Ishidoshiro🇯🇵 · T. Kikuchi🇯🇵 · T. Kishimoto🇯🇵 · A. Takeuchi🇯🇵 · R. Sato🇯🇵 · R. Smith🇬🇧

   We propose and evaluate a source-as-detector search for the de-excitation of the long-lived isomer ${}^{180\mathrm{m}}\mathrm{Ta}$ in natural tantalum (Ta), using a $\gamma$-ray transition-edge-sensor (TES) array. We exploit two capabilities not available in conventional high-purity germanium (HPGe) searches: (i) near-unity containment of low-energy secondaries (internal-conversion electrons and characteristic X rays), as well as the nuclear recoil, enabling a calorimetric, event-by-event measurement of the total energy deposited in the absorber; and (ii) a delayed-coincidence tag based on the subsequent ${}^{180}$Ta electron-capture (EC) decay to ${}^{180}$Hf. We evaluate the $3\sigma$ discovery reach for internal conversion (IC) and for dark-matter-induced de-excitation in two benchmark scenarios: a strongly interacting dark-matter (DM) subcomponent and inelastic DM with off-diagonal couplings. Using a background model based on intrinsic radioactivity in the Ta absorber and realistic detector performance, we show that arrays with $N_{\mathrm{TES}}=256$ and $1,000$ pixels can reach the theoretically expected IC half-life within $2.6$ yr and $0.66$ yr, respectively. For an array with $N_{\mathrm{TES}}=10^4$ and a five-year exposure, the projected sensitivity to DM-induced de-excitation surpasses limits inferred from HPGe non-observations of ${}^{180\mathrm{m}}$Ta and probes regions of parameter space not covered by current direct-detection experiments.

   hep-phnucl-exphysics.ins-detPRD(2026)·0 citations
3. 03*

   Viability of Sub-TeV Higgsino Dark Matter with Nearly Mass-Degenerate Sleptons

   Yuanfang Yue🇨🇳 · Yuetao Wang🇨🇳

   The higgsino-like neutralino is a compelling dark matter candidate motivated by both cosmology and naturalness considerations. While a pure higgsino typically requires a mass of around $1.1\mathrm{TeV}$ to satisfy the observed thermal relic abundance, the presence of light sleptons can significantly alter this requirement. In this work, we revisit higgsino dark matter within the Minimal Supersymmetric Standard Model (MSSM), focusing on scenarios with slepton coannihilation. We find that the presence of nearly mass-degenerate sleptons in the thermal bath can allow the higgsino mass to be as light as $\sim 400$ GeV while satisfying relic density constraints. We explicitly contrast the impact of recent direct detection updates: the LZ-2022 limits raise this lower bound to approximately $450\mathrm{GeV}$, while the stringent LZ-2024 constraints further shift the viable mass floor to $\sim 500\mathrm{GeV}$. Crucially, we demonstrate that the direct detection sensitivity is strongly dependent on the relative signs of the gaugino mass parameters $M_1$ and $M_2$. We find that scenarios with $M_1,M_2>0$ are fully excluded by LZ-2024. Conversely, configurations with opposite signs ($M_1/M_2<0$) remain broadly viable, as destructive interference in the neutralino-Higgs coupling efficiently suppresses the spin-independent cross section. Finally, we delineate the remaining viable parameter space for both the opposite-sign cases and the specific configurations with negative $M_1$ and $M_2$.

   hep-phPRD(2026)·1 citation
4. 04*

   The Minimal Supersymmetric Standard Model with Non-Invertible Selection Rules

   Yuichiro Nakai🇨🇳 · Hajime Otsuka🇯🇵 · Yoshihiro Shigekami🇨🇳 · Zhihao Zhang🇨🇳

   We investigate a framework of the Minimal Supersymmetric Standard Model (MSSM) in which the quark and lepton flavor structure and suppression of flavor-changing neutral currents (FCNCs) are governed by non-invertible selection rules. By implementing such non-group-like fusion rules for matter fields, arising from gauging the outer automorphism ${\mathbb{Z}}_2$ of a discrete ${\mathbb{Z}}_N$ symmetry, we obtain realistic Yukawa textures that reproduce the observed quark and lepton masses and mixings while ensuring diagonal soft supersymmetry (SUSY) breaking masses and hence suppressing dangerous FCNC processes. We analyze mass insertion parameters under random $\mathcal{O}(1)$ coefficients and find that all flavor-violating effects are consistent with experimental limits on processes such as $\mu \to e\gamma$ and meson mixings. We show that the Yukawa textures and soft terms remain stable under renormalization group evolution. Our results demonstrate that non-invertible selection rules provide a compelling new mechanism to address both the flavor structure and FCNC problems in supersymmetric models.

   hep-phhep-thEPJC(2026)·11 citations
5. 05*

   The Compact X and Z and their Invisible Molecular Partners

   A. Carducci🇮🇹 · B. Grinstein🇺🇸 · D. Germani🇮🇹 · A.D. Polosa🇮🇹

   We propose a model explaining the strong isospin violations observed in X(3872) decays. The X is assumed to be a compact isosinglet tetraquark and its charged partners to form an isotriplet, together with an additional neutral state mixing with the isosinglet. The isotriplet results from the loose binding of open charm mesons and, in isolation, has strongly suppressed production rates. However, its neutral component can still mix with the isosinglet and induce the large isospin violations observed. The compact-isosinglet/molecular-isotriplet pattern appears reversed when the Z(3900) resonances are considered. The Z particles observed correspond to a compact isotriplet and there is no evidence of a neutral isosinglet Z. We show that no isospin violation in the Z decays is expected.

   hep-phJHEP(2026)·4 citations
6. 06*

   Deep-learning jet flavor tagging for precision hadronic Higgs measurements at future $e^{+}{e}^{-}$ Higgs factories

   Xinzhu Wang🇨🇳 · Yifan Zhu🇨🇳 · Chunxiang Zhu🇨🇳 · Jianfeng Jiang🇨🇳 · Manqi Ruan🇨🇳 · Kun Wang · Haijun Yang🇨🇳 · Yongfeng Zhu🇨🇳

   Precise measurements of Higgs decays into quarks and gluons are essential for probing the Yukawa couplings of the Higgs boson and testing the flavor structure of the Standard Model. We investigate the process $e^{+}{e}^{-}\to ZH$ at $\sqrt{s}=240\mathrm{GeV}$ at a future $e^{+}{e}^{-}$ Higgs factory, taking the CEPC design as a benchmark. The analysis focuses on events with $Z\to \nu \bar{\nu }$ and hadronic Higgs decays $H\to b\bar{b}$, $c\bar{c}$, $s\bar{s}$ and $gg$. Jet flavor is identified using state-of-the-art particle-level deep neural network taggers (ParticleNet, Particle Transformer and More-Interaction Particle Transformer), whose per-jet outputs are combined with global event observables in a two-stage analysis employing XGBoost classifiers to separate the four Higgs decay modes from the dominant two- and four-fermion Standard Model backgrounds. Assuming an integrated luminosity of $20{\mathrm{ab}}^{-1}$, we obtain projected relative precision on $\sigma (ZH)\times \mathrm{Br}(H\to X)$ of 0.17% for $X=b\bar{b}$, 1.06% for $c\bar{c}$, 0.50% for $gg$ and 68% for $s\bar{s}$. Compared with the CEPC published results, the precisions for $H\to c\bar{c}$ and $H\to gg$ are improved by about 43% and 29%, respectively. For $H\to s\bar{s}$ we present a quantitative sensitivity estimation corresponding to a statistical significance of about $1.5\sigma$. These results highlight the potential of deep-learning-based jet flavor tagging for precision studies of Higgs decays at future $e^{+}{e}^{-}$ Higgs factories.

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

   Dipole-dipole scattering: summing large Pomeron loops in non-linear evolution with leading twist kernel

   Eugene Levin (Tel Aviv University.)🇮🇱

   It is shown in this paper that the QCD equations for dipole density have the natural solution: the 'fan' diagrams of the Pomeron calculus. We found the dipole densities comparing the analytic solution to the Balitsky-Kovchegov (BK) equation for the simplified leading twist kernel with the $t$ channel unitarity. Using these densities we calculate the contributions of large Pomeron loops to dipole-dipole scattering at high energies. Applying the Abramovsky,Gribov and Kancheli cutting rules we found that the produced gluons are distributed accordingly the KNO (Koba, Nielsen and Olesen) law which leads to the entropy $S_E=\ln (xG(x,Q^2))$ in an agreement with Kharzeev - Levin predictions.

   hep-phPRD(2026)·1 citation
8. 08*

   Kaon T-even transverse-momentum-dependent distributions and form factors in a self-consistent light-front quark model

   Yongwoo Choi🇰🇷 · Ahmad Jafar Arifi🇯🇵 · Ho-Meoyng Choi🇰🇷 · Chueng-Ryong Ji🇺🇸

   We present a self-consistent light-front quark model (LFQM) for the kaon based on the Bakamjian--Thomas (BT) construction and apply it to the electromagnetic and scalar form factors, as well as the full set of unpolarized T-even transverse-momentum-dependent distributions (TMDs) and their collinear parton distribution functions (PDFs). A uniform implementation of the invariant mass $M_0$ in both the hadronic matrix elements and the associated Lorentz structures enforces four-momentum conservation at the meson--quark vertex and yields current-component--independent observables by consistently incorporating the light-front zero-mode structure required by covariance. The electromagnetic form factor $F_{K^{+}}(Q^2)$ is demonstrated to be unique by explicit computation from all available current components (${\gamma }^{+}$, ${\gamma }^{\perp }$, and ${\gamma }^{-}$). In the scalar channel, we compare the direct $f_S(Q^2)$ and mass-factored $F_S(Q^2)$ definitions and show that they are not interchangeable within the BT-based LFQM, since the replacement $M\to M_0(x,{\mathbf{k}}_{\perp })$ must be implemented at the integrand level. Using a Gaussian light-front wave function, the twist-2 TMD $f_1^q$ exhibits an exact Gaussian dependence in ${\mathbf{k}}_{\perp }$, while higher-twist TMDs ($f^{\perp q}$, $e^q$, $f_4^q$) display systematic twist and flavor hierarchies. We further analyze the perturbative QCD evolution of the valence PDFs for the pion and kaon and report their Mellin moments at representative scales, enabling direct comparison with phenomenology.

   hep-ph4 citations
9. 09*

   Determination of the HERA coherent diffractive $J/\psi$ production cross section via artificial neural network

   Taufiq Iqbal Baihaqi · Chalis Setyadi🇮🇩 · Zulkaida Akbar🇺🇸 · Parada T. P. Hutauruk🇰🇷 · Apriadi Salim Adam🇮🇩

   An exclusive coherent diffractive $J/\psi$ production dataset from HERA, covering a large kinematic range in the photon virtuality $Q^2$, the squared momentum transfer $t$, and the photon-proton center-of-mass energy $W$, has been analyzed using various theoretical models with different approaches. In common model analyses, the inherent assumptions and limited kinematic applicability somewhat restrict the predictive power of the models, resulting in model-dependent prediction results. In this paper, we present our model-independent approach for the same reaction process and dataset, utilizing an artificial neural network (ANN) technique. The prediction of the best ANN model for the HERA differential cross-section dataset over a range of $W$, $Q^2$, and $t$ is obtained. We then extend the ANN model by combining the HERA and LHC data at various values of $W$ to predict the total photoproduction cross-section and demonstrate how to extract the exponential slope $b$. We find that the exponential slope $b$ strongly depends on $Q^2$ and $W$.

   hep-phhep-exModern Physics Letters A (2026): 2642006·3 citations
10. 10*

    On-Shell Renormalization of Dim-8 SMEFT from Complete Amplitude Basis: I. Four-Fermion Operators

    Chao Wu🇨🇳 · Ming-Lei Xiao🇨🇳 · Jiang-Hao Yu🇨🇳 · Yu-Hui Zheng🇰🇷

    We compute the complete one-loop renormalization group equations (RGEs) for all the four-fermion operators at dimension-8 Standard Model Effective Field Theory (SMEFT). We adopt the on-shell framework, where the RGEs are obtained from the unitarity cuts of the bubble integrals. To construct a consistent set of RGEs without redundancy, we utilize the Young Tensor amplitude/operator basis as the building blocks of the tree-level amplitudes that constitute the unitarity cuts, which incorporates the full flavor structures of the effective operators. Due to the large number of effective operators for a dimension-8 type, it is crucial to reduce the integrated cuts to the same RGE amplitude basis, which is also made possible by the algorithm in the Young Tensor method. With the Mathematica package ABC4EFT that implements the method, we obtain the full result of the dimension-8 four-fermion RGEs with the output file attached as the supplementary material.

    hep-phJHEP(2026)·5 citations
11. 11*

    Absence of CP Violation in the Scalar Sector of a Higgs Triplet Model

    Matheo Escobar🇨🇱 · Sebastian Olivares🇨🇱

    We investigate the potential for spontaneous CP violation in a Higgs Triplet Model extension, including a complex singlet scalar. We demonstrate that the scalar potential strictly forbids spontaneous CP violation across the entire parameter space. For a non-zero trilinear coupling $\kappa$, minimization conditions combined with global symmetries enforce a phase alignment that yields a real vacuum. In the singular limit $\kappa \to 0$, we show that the enhancement of global symmetries renders unphysical vacuum phases. Consequently, we conclude that the scalar sector of this model cannot source CP violation.

    hep-ph0 citations
12. 12*

    Radiative $H_{1,2}^{+}{W}^{-}Z$ vertices in flavour conserving three Higgs-doublet scenarios

    Nabarun Chakrabarty🇮🇳 · Indrani Chakraborty🇮🇳

    A detailed calculation of the radiatively induced $H_{1,2}^{+}{W}^{-}Z$ vertices is carried out in the context of flavour conserving three Higgs doublet models (3HDMs). The Type-II, lepton specific and democratic versions of the 3HDM are chosen as representative cases and the \emph{alignment limit} is adopted. We arrange the amplitudes in UV-finite and gauge-invariant subsets for a sharper understanding of the underlying one-loop structure. Factoring-in various theoretical constraints and the ones from the $h\to \gamma \gamma$ signal strength and the $B\to X_s\gamma$ branching ratio, we compute the relevant form factors and compare them among the various 3HDM types taken. The results also indicate a sizeable increment ($\sim 100\%$) over the corresponding form factors in 2HDMs. In addition, we probe the $H_{1,2}^{+}{W}^{-}Z$ vertices at the 14 TeV LHC using vector boson fusion (VBF). It is seen that production of $H_1^{+}$ via VBF and the subsequent $H_1^{+}\to H_2^{+}{H}_2/A_2$ decays can have $\sigma \times \text{BR}$ in the $\mathcal{O}$(0.1 fb) ball park. Therefore, such a cascade can shed light on the strength of the $H_1^{+}{W}^{-}Z$ interaction and confirm the presence of two charged scalars thereby acting as a smoking gun signal of a 3HDM.

    hep-ph0 citations
13. 13*

    Differentiable Principal-Value Inversion for Neural-Network Extraction of Generalized Parton Distributions

    Dima Watkins🇺🇸 · Ishara Fernando🇺🇸 · Dustin Keller🇺🇸

    We present a machine-learning method for the nonparametric extraction of generalized parton distributions (GPDs) from Compton form factors (CFFs) constrained by experimental data. The method addresses the longstanding inverse problem posed by the principal-value (PV) linear integral transform with a singular kernel that relates the charge-conjugation-even (C-even) quark GPD $H^{(+)}$ to the real part of the deeply virtual Compton scattering (DVCS) amplitude. Our approach constructs a differentiable representation of the Quantum Chromodynamics (QCD) PV kernel and embeds it as a fixed, physics-preserving layer inside a neural network that parameterizes the GPD $H^{(+)}(x,\xi ,t,Q^2)$ itself. The model enforces exact oddness in $x$, implements endpoint suppression, and includes curvature-based regularization that stabilizes the inversion in kinematically ill-conditioned regions. A Monte Carlo ensemble of CFFs, obtained from a global neural-network fit to unpolarized DVCS measurements with propagated experimental uncertainties, serves as input to a replica ensemble of GPD networks, yielding a fully probabilistic extraction of $H^{(+)}$ over the phase space. We demonstrate the method using a global determination of $\mathrm{Re}\mathcal{H}$ for Jefferson Lab measurements, and present a direct neural-network reconstruction of three-dimensional GPD surfaces $H^{(+)}(x_0,\xi ,t,Q_0^2)$ obtained from experimental CFF inputs. This work establishes a flexible, scalable, and model-independent strategy for extracting multidimensional hadronic structure from current and future DVCS data and other GPD-related processes.

    hep-ph4 citations
14. 14*

    Dark Higgs in Hidden Sector as a Probe for Dark Matter

    Faeq Abed🇪🇬 · Asmaa AlMellah🇹🇼 · Gaber Faisel🇹🇼

    This study presents a sensitivity analysis of exotic Higgs boson decays at the electron--positron stage of the Future Circular Collider (FCC-ee), performed within the FCCAnalyses framework. The analysis investigates Higgs boson production in association with a Z boson in electron--positron collisions at a center-of-mass energy of 240~GeV. The Higgs boson is assumed to decay into a pair of long-lived scalar particles, while the Z boson decays leptonically. A hadronic final state is considered, in which the long-lived scalars subsequently decay into bottom--antibottom quark pairs. The simulation chain is implemented using the FCCAnalyses framework, with event generation performed using \textsc{MadGraph} and \textsc{Pythia}, and detector effects modeled with \textsc{Delphes}. Displaced vertices arising from the decays of long-lived particles are reconstructed using the FCCAnalyses implementation of the \textsc{LCFIPlus} secondary vertex finding algorithm, enhanced with extended features such as customized track selection. The final event selection requires the reconstruction of a Z boson together with at least two displaced vertices. This strategy efficiently suppresses Standard Model backgrounds while retaining at least three expected signal events, including statistical uncertainties, over most of the explored parameter space. The study considers scalar masses of 20~GeV and 60~GeV and mixing angles of $10^{-5}$, $10^{-6}$, and $10^{-7}$. The results demonstrate that FCC-ee will be sensitive to long-lived scalars with decay lengths ranging from approximately 1~mm to 10~m, with optimal sensitivity around a decay length of 0.3~m.

    ↳ hep-exhep-ph0 citations
15. 15*

    Model-Independent Bound on Neutrino Energy Reconstruction from Nuclear Targets

    Sanjeev Kumar Verma🇮🇳

    Neutrino energy reconstruction on nuclear targets underlies oscillation measurements and precision tests of weak interactions. Inclusive charged--current data have long exhibited degeneracies commonly attributed to axial-mass tuning, multinucleon dynamics, and final-state interactions. This work shows that, even in the idealized limit of perfect detectors and exact nuclear dynamics, inclusive lepton-only reconstruction admits no unique inverse. A strictly positive lower bound on neutrino energy resolution follows from the finite energy-transfer support of the inclusive nuclear axial response. The result identifies an irreducible contribution to reconstruction uncertainty that is independent of modeling assumptions and experimental resolution.

    ↳ nucl-thhep-ph0 citations
16. 16*

    $Sp(4,\mathbb{Z})$ modular inflation

    Si-Yi Jiang🇨🇳 · Wenbin Zhao🇨🇳 · Gui-Jun Ding🇨🇳

    We investigate inflation models governed by the Siegel modular group $Sp(4,\mathbb{Z})$. The $Sp(4,\mathbb{Z})$ group extends the $SL(2,\mathbb{Z})$ framework from one modulus to three moduli while preserving the hyperbolic geometry of the Kähler potential, allowing for the construction of cosmological $\alpha$-attractor models. In this context, we use genus $g=2$ absolute invariants to construct inflationary potentials within specific subspaces of the Siegel moduli space. These models are driven by the imaginary components of the moduli $\tau$ and naturally yield plateau-like potentials consistent with Planck 2018 observations in large field limit. We employ two-dimensional complex subspaces to realize E-model and T-model like two-field inflation scenarios. We explore the subspace of complex dimension one to construct a modified polynomial $\alpha$-attractor model, which can accommodate the larger spectral index $n_s$ favored by recent ACT and SPT data, particularly in the larger $N$ regime.

    ↳ hep-thastro-ph.COhep-phJCAP(2026)·3 citations
17. 17*

    Particle production and Higgs reheating

    Aarav Shah🇫🇷 · Kanabar Jay🇮🇳 · Maxim Khlopov🇫🇷 · Oem Trivedi🇺🇸 · Maxim Krasnov🇷🇺

    Reheating is essential for transforming the cold, vacuum dominated Universe at the end of inflation into the hot thermal bath required by the Standard Model. In many well motivated inflationary models, however, the inflaton has no direct couplings to other fields, raising the question of how the Universe becomes repopulated with particles. We address this question within the framework of geometric reheating, where energy transfer occurs purely through gravitational effects. Focusing on a Higgs inflationary scenario with a non-minimal curvature coupling $\xi {\varphi }^{2}R$, we derive the post-inflationary dynamics and compute particle production using the Bogoliubov formalism. We show that the rapid, oscillatory evolution of the curvature scalar after inflaton acts as a time dependent gravitational pump, creating scalar spectator particles even in the absence of explicit interactions. This curvature driven production mechanism provides a natural and efficient route to reheating, demonstrating that gravity alone can initiate the standard thermal history and bridge inflation with radiation domination in minimal, coupling free models of the early Universe.

    ↳ astro-ph.COgr-qchep-phhep-th2 citations
18. 18*

    Classifying fusion rules of anyons or SymTFTs: A general algebraic formula for domain wall problems and quantum phase transitions

    Yoshiki Fukusumi🇹🇼

    We propose a formula for the transformation law of anyons in topologically ordered phases or topological quantum field theories (TQFTs) through a gapped or symmetry-preserving domain wall. Our formalism is based on the ring homomorphism between the $\mathbb{C}$-linear commutative fusion rings, also known as symmetry topological field theories (SymTFTs). The fundamental assumption in our formalism is the validity of the Verlinde formula, applicable to commutative fusion rings. By combining it with more specific data of the settings, our formula provides classifications of anyons compatible with developing categorical formulations. It also provides the massless renormalization group (RG) flows between conformal field theories (CFTs), or a series of measurement-induced quantum phase transitions, in the language of SymTFT, through the established correspondence between CFTs and TQFTs. Moreover, by studying the correspondence between the ideal structure in the massless RG and the module in the related massive RG, one can make the Nambu-Goldstone-type arguments for generalized symmetry. By combining our formula with orbifolding, extension, and similarity transformation, one can get a series of classifications for the corresponding extended models, or symmetry-enriched topological orders and quantum criticalities.

    ↳ hep-thcond-mat.str-elhep-phmath-ph+2PRB(2026)·4 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.