PaperPanorama

Nuclear Theory·nucl-th

Wednesday·January 21, 2026

30 papers13 primary·17 cross-listed

  1. 14

    [Submitted on 16 Jan 2026] (cross-list from math-ph)

    Existence of Decreasing Nambu Solutions to the Rainbow Ladder Gap Equation of QCD by Cone Compression

    Alex Roberts

    Studying Nambu solutions of the rainbow-ladder gap equation in QCD at zero temperature and chemical potential, we prove that the mass function emerges continuously from zero as the interaction strength is increased past the critical point for all positive, asymptotically perturbative kernels almost everywhere continuous in using the Krasnosel'skii-Guo Cone Compression Theorem. We prove that the coupled system of equations must have a positive, continuous Nambu solution with decreasing mass function for all current quark masses for a class of models which includes the physical point of a popular model of QCD by using a hybrid Krasnosel'skii-Schauder Fixed Point Theorem.

    Subjects:
    Mathematical Physics (math-ph); math.FA (math.FA); math.MP (math.MP); Nuclear Theory (nucl-th)
    arXiv:
    2601.11752 [pdf]
    0 citations
  2. 15

    [Submitted on 16 Jan 2026] (cross-list from hep-ph)

    Minkowski Space Dynamics and Light-Front Projection

    Wayne de Paula🇧🇷 · Tobias Frederico🇧🇷

    We explore the connection between the four-dimensional Minkowski-space Bethe-Salpeter equation and its light-front projection, emphasizing the implications for bound-state dynamics. Our approach incorporates dressed particles, such as quarks, via the integral representation of the corresponding propagator. We analyze the light-front dynamics of the valence component of the physical state using a hierarchical set of Green's functions, which reveals its coupling to higher Fock components when dressed particles are considered. We also present the light-front Faddeev-Bethe-Salpeter equations for three-body systems with dressed constituents. Furthermore, we discuss formal developments that are central to connecting the three-dimensional light-front dynamics onto the null-plane and the four-dimensional Minkowski-space framework, based on the Nakanishi integral representation. Selected applications to hadron structure are also reviewed.

    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
    arXiv:
    2601.11760 [pdf]
    Eur.Phys.J.ST(2026)·2 citations
  3. 16

    [Submitted on 17 Jan 2026] (cross-list from hep-lat)

    Asymptotic Long-Distance Expansion of Euclidean Correlators in Lattice Parton Applications

    Xiangdong Ji🇨🇳 · Yizhuang Liu🇵🇱 · Yushan Su🇺🇸

    Bilinear Euclidean quark and gluon correlators with Wilson links have been used widely for applications of large-momentum effective field theories to computing non-perturbative collinear and soft parton physics. Due to color confinement, these correlators decay exponentially at large spatial distances, a behavior crucial for computing momentum-space Fourier transformations with controlled errors from lattice QCD data. Using heavy-quark effective theory reduction, dispersive analysis, Lorentz symmetry, and heavy-flavor spectra, we determine the leading and next-to-leading asymptotic behaviors and relate the expansion parameters to binding energies of heavy-flavor hadrons. We demonstrate the results through two-loop calculations in theory and from the perspective of locality and analyticity. We also study the impact of the asymptotic analysis on realistic lattice QCD data and demonstrate reliable error estimates.

    Comments:
    93 pages, 32 figures
    Subjects:
    High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
    arXiv:
    2601.12189 [pdf]
    14 citations
  4. 17

    [Submitted on 18 Jan 2026] (cross-list from hep-ph)

    Open charm production and ratio in pp and Au+Au collisions at the RHIC

    Bijun Fan🇨🇳 · Chao Zhang🇨🇳 · Liang Zheng🇨🇳 · Shusu Shi🇨🇳

    We study open charm hadrons production in pp and Au+Au collisions at ~GeV using an improved a multi-phase transport (AMPT) model. Specifically, we show the transverse-momentum spectra and nuclear modification factors of mesons and baryons, as well as the ratio in pp and Au+Au collisions. The results obtained from the AMPT model simulations are compared with the STAR experimental data and found to be consistent. We further investigate the ratio by evaluating contributions from coalescence, fragmentation, and the combined coalescence+fragmentation mechanisms, and we find that fragmentation alone underestimates the pronounced enhancement in Au+Au relative to pp at low and intermediate , whereas the coalescence+fragmentation mechanism reproduces the observed trend significantly better. These results indicate that coalescence plays a key role in charm baryon productions and helps constrain the relative importance of different hadronization mechanisms in the ultra-relativistic nuclear collisions.

    Comments:
    9 pages, 5 figures
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    2601.12287 [pdf]
    PRC(2026)·1 citation
  5. 18

    [Submitted on 18 Jan 2026] (cross-list from nucl-ex)

    Impact of the Li resonance in - elastic scattering on precision measurements of neutrino oscillation parameters

    Mingyuan Wang🇨🇳 · Yiyang Li🇨🇳 · Suqing Hou🇨🇳 · Fei Xiao🇨🇳 · Yaoguang Wang🇨🇳 · Zeyuan Yu🇨🇳

    Precision measurements of four neutrino oscillation parameters, , , , and ||, face significant interference from a previously overlooked correlated background. Recent findings from the SNO+ and JUNO experiments reveal that cascade decays of Bi-Po in liquid scintillator detectors can mimic inverse beta decay signals from reactor and geoneutrinos, with a misidentification probability on the order of when hydrogen neutron capture is used, a rate ten times higher than Geant4 simulations predicted. This work identifies the Li resonance in - elastic scattering as the underlying cause. For alpha energies above 5~MeV, the cross section is hundreds of times larger than that of Rutherford scattering. After correctly incorporating the differential cross section into Geant4, the misidentification probability is recalculated as 1.910. The simulated shape of the long tail in the alpha deposited energy also differs from the extrapolation models currently used by SNO+ and JUNO. These results will assist both experiments in more accurately estimating this novel background, thereby refining measurements of neutrino oscillation parameters and the geoneutrino flux. Additionally, the study implies an overlooked background with a rate of 0.5 events per detector per day in the Daya Bay analysis using hydrogen neutron capture, leading to an increase of by approximately 0.012. Consequently, the Particle Data Group's reported value shall increase by about 0.006~(1).

    Subjects:
    Nuclear Experiment (nucl-ex); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
    arXiv:
    2601.12452 [pdf]
    0 citations
  6. 19

    [Submitted on 19 Jan 2026] (cross-list from hep-ph)

    QCD-Like Theories with Different Color Numbers

    Toru Kojo🇯🇵

    Quantum chromodynamics (QCD) with a general number of colors, , provides a powerful theoretical laboratory to explore the dynamics of non-Abelian gauge theories. Although does not look a large number, the expansion provides us with a very useful classification and book-keeping scheme for hadronic processes and sharpens conceptions otherwise obscured in real-world QCD with . Important applications are dense QCD matter where the first principle methods for QCD are not available and many conceptual issues remain to be clarified. In this chapter we first review hadrons at large from the viewpoint of quark-gluon dynamics, and then extend the discussions to hot/dense matter, focusing on confinement-deconfinement aspects. We emphasize how the large- limit provides a unified organizing principle for hadronic and quark degrees of freedom in regimes where first-principle methods are limited. Two-color and isospin QCD, for which lattice simulations at finite density can be performed for a special reason, is reviewed.

    Comments:
    15 pages, 8 figures, a contribution to the Encyclopedia of Nuclear Physics
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    2601.12650 [pdf]
    0 citations
  7. 20

    [Submitted on 19 Jan 2026] (cross-list from hep-ph)

    Investigation of deuteron-like singly bottomed dibaryon resonances

    Yuxuan Du🇨🇳 · Yanyue Pan🇨🇳 · Xinmei Zhu🇨🇳 · Zhiyun Tan🇨🇳 · Hongxia Huang🇨🇳 · Jialun Ping🇨🇳

    We perform a systematical investigation of the existence of the deuteron-like singly bottomed dibaryon resonance states with strangeness in the chiral quark model. Two resonance states with strangeness are obtained in the baryon-baryon scattering process. The first candidate is in the and scattering process, with the resonance energy 6974.22 MeV - 6975.37 MeV and the decay width 14.450 MeV, respectively; the other one is in the and scattering process, with the resonance energy 6990.69 MeV - 7008.37 MeV and the decay width 43.790 MeV, respectively. The Root Mean Square (RMS) radius calculation shows that the former tends to be in a compact structure, while the latter tends to be in a molecular structure. Both of these resonance states are worthy of experimental exploration. Furthermore, it should be emphasized that the effect of channel-coupling is of great importance in exploring exotic hadron states, and investigating the scattering process may serve as an effective approach to identifying genuine resonances.

    Comments:
    17 pages, 5 figures
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); High Energy Physics — Lattice (hep-lat); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
    arXiv:
    2601.12670 [pdf]
    PRD(2026)·0 citations
  8. 21

    [Submitted on 19 Jan 2026] (cross-list from nucl-ex)

    Electric dipole strength in -shell nuclei from small-angle proton scattering

    R.W. Fearick (1)🇿🇦 · O. Le Noan (2,3)🇫🇷 · H. Matsubara (4,5)🇯🇵 · P. von Neumann-Cosel (6)🇩🇪 · K. Sieja (2,3)🇫🇷 · A. Tamii (4) ((1) Department of Physics, University of Cape Town, Rondebosch 7700, South Africa, (2) Universite de Strasbourg, IPHC, 23 rue du Loess, 67037 Strasbourg, France, (3) CNRS, UMR7178, 67637 Strasbourg, France, (4) Research Center for Nuclear Physics, Osaka University, Ibaraki, Osaka 567-0047, Japan (5) School of Medical Sciences, Fujita Health University, Aichi 470-1192, Japan, (6) Institut für Kernphysik, Technische Universität Darmstadt, D-64289 Darmstadt, Germany)🇯🇵

    The present work reports new total photoabsorption cross sections for the nuclei in the -shell Ne, Mg, Si, S, Ar, and for Mg. The results are compared to predictions of a data-driven artificial neural network application and to configuration-interaction shell-model calculations covering the excitation energy region of the isovector giant dipole resonance. Double-differential cross sections of the reaction at 295 MeV have been measured between and . The angular distributions of the parts due to Coulomb excitation have been extracted with a multipole decomposition analysis for excitation energies 12 to 24 MeV and converted to equivalent photoabsorption cross sections with the virtual photon method. Reasonable agreement of the photoabsorption cross sections with previous experiments is found for Mg and Si, while the present results diverge for S. For the first time, data are presented for Ne, Mg and Ar. Configuration-interaction shell-model calculations provide an overall satisfactory description of the fragmented strength distributions. The same holds for absolute cross sections except for Mg and Ar, where the experimental results significantly exceed the expected exhaustion of the Thomas-Reiche-Kuhn energy-weighted sum rule. Fot light nuclei, there is a larger model dependence compared to previous analyses in heavy nuclei, in particular for excitation energies above 20 MeV, due to the need to constrain the continuum background with additional assumptions. The overall success of the shell-model approach to describe the features of the experimental photoabsorption cross sections motivates its application in large-scale reaction network calculations aiming at an understanding of the mass composition of ultrahigh-energy cosmic rays.

    Comments:
    10 pages, 6 figures
    Subjects:
    Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
    arXiv:
    2601.12829 [pdf]
    PRC(2026)·0 citations
  9. 22

    [Submitted on 19 Jan 2026] (cross-list from hep-lat)

    Lattice-QCD validation of hadron mass and trace-anomaly decomposition sum rules

    Dennis Bollweg🇺🇸 · Heng-Tong Ding🇨🇳 · Xiang Gao🇺🇸 · Ran Luo🇨🇳 · Swagato Mukherjee🇺🇸

    We present the first lattice-QCD validation of multiple sum rules associated with quark-gluon decomposition of hadron mass by computing all components from first principles. We achieve this through nonperturbative renormalization of the QCD energy-momentum tensor, including its trace, in a gradient-flow scheme, followed by continuum extrapolations, two-loop matching to the scheme, and zero-flow-time extrapolations. These ingredients enable a direct and simultaneous verification, in a common renormalization scheme and scale, of multiple energy-density-based and trace-based mass decomposition sum rules proposed in the literature. We demonstrate the framework for the and charmonia using three fine lattice spacings with a physical strange-quark and near-physical up- and down-quark masses. We present the first lattice-QCD results for the gravitational form factor . We find sizable gluonic contributions to charmonia masses at the hadronic scale, in the Lorcé and Metz-Pasquini-Rodini decompositions. The trace-anomaly contribution in the Ji sum rule is , while the gluonic component of the trace anomaly in the Hatta-Rajan-Tanaka sum rule is . The method is general and can be straightforwardly adopted for lattice-QCD calculations of mass and spin decompositions as well as gravitational form factors of other hadrons and nuclei.

    Comments:
    22 pages, 15 figures
    Subjects:
    High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    2601.13070 [pdf]
    PRL(2026)·2 citations
  10. 23

    [Submitted on 19 Jan 2026] (cross-list from hep-ph)

    Heavy Quarks in the initial stages of Proton-Ion Collisions

    Gabriele Parisi🇮🇹

    Collisions among heavy ions, like Pb or Au, are a great tool to study the theory of strong interactions, that is Quantum Chromodynamics (QCD). In particular, these experiments are able to give insights on all the complex phases of matter that the theory of QCD allows. In this PhD Thesis we have investigated the initial stages of proton-ion collisions: in particular, we will focus on the first fm/c ( s) after the collision, which are dominated by very intense gluon fields, in a state called glasma. We investigated the effect of such fields on the dynamics of heavy quarks (charm and beauty) which are created and evolve in this medium. The effect of the initial gluon fields on heavy quarks is quite substantial, in particular we observe that the glasma provokes a dissociation rate on quark-antiquark pairs. Moreover, glasma fields have a large momentum anisotropy, and transmit a large part of such anisotropy to the heavy quarks which evolve in this medium. Finally, we have generalized our study to a non-boost invariant medium, and shown that fluctuations in rapidity do not lead to significant isotropization within glasma timescales.

    Comments:
    PhD thesis submitted on November 30th, 2025. Largely based on arXiv:2412.07967, arXiv:2505.08441 and (preliminary results of) arXiv:2601.11123
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
    arXiv:
    2601.13076 [pdf]
    0 citations
  11. 24

    [Submitted on 19 Jan 2026] (cross-list from hep-ph)

    Bottom-up approach to describe groomed jet data in heavy-ion collisions

    Liliana Apolinário🇵🇹 · Diogo Costa🇪🇸 · Alba Soto-Ontoso🇪🇸

    The theoretical interpretation of jet observables in heavy-ion collisions is a complex task due to the intricate interplay of perturbative and non-perturbative effects. One way to reduce this complexity is to groom away soft, wide-angle radiation so that perturbative dynamics dominates. Even in this simplified scenario, there are competing explanations for the physical origin of the measured medium-induced modifications. In this paper, we present a minimal approach to compute groomed substructure observables. The core idea is to treat medium effects as an effective energy shift of the hard, vacuum-like substructure. This energy shift includes a gradual onset of colour decoherence effects and thus depends on the jet substructure itself. We first study a NLO-exact dijet configuration in vacuum and apply radiative energy-loss to the two subjets. We find that this minimal setup already captures the narrowing trend of groomed observables but it's not able to quantitatively describe the existing data. Next, we match the NLO matrix-element to a leading-logarithm accurate parton shower and perform a clustering algorithm to recover a two-prong system to which we again apply the energy-loss distribution. Despite its simplicity, the model results in a very good theory-to-data agreement (within ) for a broad range of observables including both ALICE and ATLAS kinematics. We also examine the discriminating power of groomed jet data in terms of colour decoherence effects and find that substructure-dependent energy loss yields an overall better agreement.

    Comments:
    17 pages, 6 figures, 2 appendices
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
    arXiv:
    2601.13310 [pdf]
    EPJC(2026)·7 citations
  12. 25

    [Submitted on 19 Jan 2026] (cross-list from cs.LG)

    Quantum Qualifiers for Neural Network Model Selection in Hadronic Physics

    Brandon B. Le · D. Keller

    As quantum machine-learning architectures mature, a central challenge is no longer their construction, but identifying the regimes in which they offer practical advantages over classical approaches. In this work, we introduce a framework for addressing this question in data-driven hadronic physics problems by developing diagnostic tools - centered on a quantitative quantum qualifier - that guide model selection between classical and quantum deep neural networks based on intrinsic properties of the data. Using controlled classification and regression studies, we show how relative model performance follows systematic trends in complexity, noise, and dimensionality, and how these trends can be distilled into a predictive criterion. We then demonstrate the utility of this approach through an application to Compton form factor extraction from deeply virtual Compton scattering, where the quantum qualifier identifies kinematic regimes favorable to quantum models. Together, these results establish a principled framework for deploying quantum machine-learning tools in precision hadronic physics.

    Comments:
    12 pages, 5 figures. Proceedings for the 26th International Symposium on Spin Physics (SPIN2025), September 21-26, 2025; Qingdao, Shandong, China
    Subjects:
    Machine Learning (cs.LG); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th); Quantum Physics (quant-ph)
    arXiv:
    2601.13463 [pdf]
    1 citation
  13. 26

    [Submitted on 20 Jan 2026] (cross-list from hep-ph)

    Non-perturbative flavor asymmetry in the nucleon and deuteron: The light-front Hamiltonian effective field theory approach

    Xianghui Cao🇨🇳 · Shan Cheng🇨🇳 · Yihan Duan🇨🇳 · Yang Li🇨🇳 · Siqi Xu🇨🇳 · Xingbo Zhao🇨🇳

    We investigate non-perturbative multi-pion contributions to nucleon flavor asymmetry within the framework of Light-Front Hamiltonian Effective Field Theory (LFHEFT). Utilizing a Fock sector expansion, we systematically incorporate pionic degrees of freedom, with the nucleon-pion interactions governed by a scalar variant of chiral effective field theory. Our results demonstrate that the non-perturbatively calculated longitudinal momentum distributions exhibit significant deviations from leading-order perturbative predictions, emphasizing the importance of higher-order Fock components in describing the proton's sea quark structure. Furthermore, we demonstrate the feasibility of extending this framework to investigate nuclear effects in light nuclei, such as the deuteron. This unified approach provides a consistent basis for analyzing the interplay between intrinsic nucleon structure and nuclear modifications, potentially offering new insights into the flavor asymmetry observed in fixed-target and collider experiments.

    Comments:
    6 pages, 3 figures, proceeding of the 2025 International Conference on the Structure of Baryons
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    2601.13567 [pdf]
    J.Subatomic Part.Cosmol.(2026)·0 citations
  14. 27

    [Submitted on 20 Jan 2026] (cross-list from hep-ph)

    Structure of Bound States with Coulomb plus Short-range Interaction

    Chisato Uno🇯🇵 · Tetsuo Hyodo🇯🇵

    We study the structure of bound states appearing in systems governed by the Coulomb and short-range interactions. We analyze the binding energies and wave functions of the bound states generated by the Coulomb plus short-range potential. We demonstrate that Coulomb-induced shifts of the binding energy are closely correlated with the spatial distribution of the wave function. Furthermore, we show that the asymptotic behavior of wave functions of weakly bound states is qualitatively altered by Coulomb repulsion, leading to a modification of the near-threshold mass scaling that is otherwise universal for short-range interactions.

    Comments:
    6 pages, 3 figures, Talk given at The 15th International Conference on Hypernuclear and Strange Particle Physics (HYP2025), Sep. 29 - Oct. 3, 2025, Tokyo, Japan
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    2601.13733 [pdf]
    0 citations
  15. 28

    [Submitted on 20 Jan 2026] (cross-list from hep-ph)

    Box at Low Energy

    Balma Duch🇪🇸 · Pere Masjuan🇪🇸 · Hubert Spiesberger🇩🇪

    We calculate the 1-loop box-graph correction to electron-quark scattering at low energy and low momentum transfer. Both electron and quark masses are kept non-zero. From our result, we extract coupling constants for the low-energy effective Lagrangian with parity-violating 4-fermion interaction terms. We study the zero-mass limits and show that a non-zero electron mass is sufficient to obtain finite, well-defined couplings which are insensitive to a hadronic mass cutoff. We finally discuss the impact of our results on the determination of the weak charge of the proton from polarized electron-proton scattering.

    Comments:
    26 pages, 6 figures
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
    arXiv:
    2601.13819 [pdf]
    1 citation
  16. 29

    [Submitted on 20 Jan 2026] (cross-list from astro-ph.HE)

    Rotational enhancement and stability of protoquark stars during thermal evolution

    Adamu Issifu🇧🇷 · Andreas Konstantinou🇨🇾 · Prashant Thakur🇰🇷 · Tobias Frederico🇧🇷

    We present the first systematic study of rigidly rotating protoquark stars based on isentropic equations of state (EOS) within the density-dependent quark mass (DDQM) framework. Using a quasi-static equilibrium approach, we follow the Kelvin--Helmholtz evolution from hot, lepton-rich matter to a cold, catalyzed quark star (QS). Rotation substantially enhances the maximum stable mass (by up to ), equatorial radius, and key rotational observables, with the ratio of rotational kinetic to gravitational potential energy, , reaching -- near the Keplerian limit, indicating a heightened susceptibility to gravitational-wave--emitting instabilities. Thermal evolution introduces a clear ordering: all stellar properties peak during the lepton-rich stages and decrease monotonically as the star cools. Compared to hadronic stars, rotating proto-QSs exhibit larger radii, higher moments of inertia, and stronger quadrupolar deformation, producing a distinct signature in the mass--radius--spin plane. The EOS parameters are constrained using current astrophysical observations, including mass--radius measurements from HESS~J1731--347 and PSR~J0030+0451, the high-mass constraint from PSR~J0740+6620, and mass-radius constraints inferred from GW170817. The results demonstrate that future multimessenger observations must account for both thermal history and rotation to identify quark matter (QM) in compact stars robustly.

    Comments:
    14 pages, 2 tables, and 8 figures (the version accepted for publication in Physical Review D)
    Subjects:
    High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    2601.13941 [pdf]
    PRD(2026)·0 citations
  17. 30

    [Submitted on 20 Jan 2026] (cross-list from hep-ph)

    Frame Dependence in Generalized Chiral Kinetic Theory

    Shu-Xiang Ma🇨🇳 · Jian-Hua Gao🇨🇳

    We investigate the frame dependence of distribution functions within the framework of generalized chiral kinetic theory. Based on the derived transformation rules governing the choice of frame, we analytically obtain the global equilibrium solution in the presence of vorticity and electromagnetic fields. Our results show that, under the assumption of a varying electromagnetic field, these equilibrium solutions can be uniquely determined.

    Comments:
    11 pages
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
    arXiv:
    2601.14010 [pdf]
    CPC(2026)·0 citations

Affiliations

first authorsco-authorsvia INSPIRE