PaperPanorama

Nuclear Theory·nucl-th

Tuesday·February 4, 2025

14 papers6 primary·8 cross-listed

  1. 01

    [Submitted on 1 Feb 2025]

    Effect of a repulsive three-body interaction on the molecule

    Ya-Wen Pan🇨🇳 · Jun-Xu Lu🇨🇳 · Emiko Hiyama🇯🇵 · Li-Sheng Geng🇨🇳 · Atsushi Hosaka🇯🇵

    The hadronic molecular picture of the observed exotic states has inspired numerous investigations into few-body systems. Recently, the lattice effective field theory studied the effect of a three-body interaction on the binding energy of the system, revealing an intriguing phenomenon in the binding energy. This work uses the Gaussian expansion method to explore the underlying physics. Our results show that as the repulsive three-body interaction strengthens, the spatial size of the bound state gradually increases. Further enhancement of the three-body interaction causes the three-body bound state to break into a two-body bound state, accompanied by a distant meson. The identical nature of the two mesons leads to the fact that the system consistently resembles an isosceles triangle-shaped spatial configuration.

    Comments:
    8 pages, 6 figures
    Subjects:
    Nuclear Theory (nucl-th); High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph)
    arXiv:
    2502.00438 [pdf]
    PRD(2025)·6 citations
  2. 02

    [Submitted on 1 Feb 2025]

    Time Evolution of Prompt Gamma-Ray Emission in Cf(sf) and U(,f) Reactions

    Patrick Talou · Amy E. Lovell · Ionel Stetcu · Gencho Rusev · Toshihiko Kawano · Marian Jandel

    We investigate the time evolution of prompt fission emission due to the presence of ns to ms isomers in the fragments produced in the neutron-induced fission of U and in the spontaneous fission of Cf. Calculations performed with the CGMF fission event generator are compared with recent experimental data on Cf(sf) and U(,f) obtained with the DANCE+NEUANCE setup at the Los Alamos Neutron Science Center. Of particular interest are the average -ray energy spectrum as a function of time since scission, , the increase of the average -ray multiplicity over time, , and its evolution in time as a function of the fission fragment mass, . The time evolution of isomeric ratios in post-neutron emission fission fragments can be defined and used to test and reveal some deficiencies in our knowledge of the low-lying levels of neutron-rich nuclei produced in fission reactions.

    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2502.00599 [pdf]
    PRC(2025)·1 citation
  3. 03

    [Submitted on 2 Feb 2025]

    The nucleon structure from an AdS/QCD model in the Veneziano limit

    Jiali Deng (CCNU)🇨🇳 · Defu Hou (CCNU)🇨🇳

    We employ the VQCD model, a holographic approach that dynamically simulates essential QCD characteristics, including linear mass spectra, confinement, asymptotic freedom, and magnetic charge screening, while incorporating quark flavor effects. Using this model, we first calculate the proton mass spectrum and the wave function, incorporating anomalous dimensions to refine our results. Next, we compute the proton structure functions across a range of Bjorken values using consistent parameters. Furthermore, we derive the proton electromagnetic form factor by solving the electromagnetic field's motion equation, accounting for background effects, and demonstrate qualitative consistency with results from free electromagnetic fields coupled to fermions. Finally, we calculate the gravitational form factors by introducing an effective graviton mass arising from chiral symmetry breaking and the proton energy-momentum tensor. Our calculations yield results that are in excellent agreement with experimental data and lattice QCD computations, validating the VQCD model as a robust tool for studying proton properties.

    Comments:
    23 pages,1 table and 8 figures in Revtex
    Subjects:
    Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
    arXiv:
    2502.00771 [pdf]
    PRD(2025)·13 citations
  4. 04

    [Submitted on 2 Feb 2025]

    Kaon Modification in Pion Medium

    Yu. B. Ivanov🇷🇺

    Kaon properties in thermal pion-nucleon medium are studied. The dense pion-nucleon medium is produced in high-energy heavy-ion collisions. The consideration is based on the chiral nucleon-kaon-pion Lagrangian. It is found that the pion medium does not produce a substantive contribution but enhances the effect of the baryon matter. Numerical estimate shows that this enhancement factor induced by the pion medium does not exceed 5% at the freeze-out stage of heavy-ion collisions, i.e. it is small. However, the impact of this enhancement can be higher in actual nuclear collisions because the effect of the in-medium (anti)kaon modification is accumulated during the (anti)kaon evolution before the freeze-out when the pion density is higher.

    Comments:
    3 pages, 1 figure, references added, discussion extended, numerical error corrected
    Subjects:
    Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
    arXiv:
    2502.00819 [pdf]
    Phys.Part.Nucl.Lett.(2025)·0 citations
  5. 05

    [Submitted on 3 Feb 2025]

    Neutron-transfer induced breakup of the Borromean nucleus Be

    G. Villanueva · A. M. Moro · J. Casal · Jin Lei

    We address the problem of evaluating neutron-transfer induced breakup cross sections caused by the Borromean nucleus Be, using the reaction Au(Be,Be)Au as a test case. This reaction was recently measured over a wide range of incident energies around the Coulomb barrier. To deal with the high density of Au states that can be potentially populated in this reaction, we employ the Ichimura, Austern, Vicent model, in which the spectrum of physical states for this system is replaced by the solutions of a complex n+Au potential, accounting effectively for the fragmentation of single-particle states into physical states. Furthermore, to account for the unbound nature of the emitted Be system, we employ a three-body model of Be. The calculated stripping cross sections are found to be in good agreement with existing data over a wide range of incident energies. The importance of taking into account the energy spread of the single-particle strength of the outgoing Be and the target-like residual nucleus is discussed.

    Comments:
    7 pages, 7 figures
    Subjects:
    Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
    arXiv:
    2502.01165 [pdf]
    PLB(2024)·7 citations
  6. 06

    [Submitted on 3 Feb 2025]

    Demystifying the fusion mechanism in heavy-ion collisions: A six-dimensional Langevin dissipative dynamics approach

    Yannen Jaganathen · Michał Kowal · Krzysztof Pomorski

    We present an in-depth investigation of heavy-ion fusion dynamics using a six-dimensional Langevin framework that enables unrestricted motion of the asymmetry parameter. The stochastic formalism naturally incorporates friction effects and energy fluctuations, providing a detailed understanding of the fusion process. The dynamics transition into the overdamped regime, facilitating rapid neck stabilization while effectively capturing the interplay between shape and rotational degrees of freedom. This approach achieves excellent agreement with experimental spin distributions and fusion cross-sections, establishing a robust foundation for forthcoming studies on the synthesis of superheavy elements and the exploration of the enigmatic fusion hindrance mechanism.

    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2502.01292 [pdf]
    PLB(2025)·3 citations
  7. 07

    [Submitted on 29 Jan 2025] (cross-list from hep-lat)

    and interactions from lattice QCD

    Yan Lyu · Takumi Doi🇯🇵 · Tetsuo Hatsuda🇯🇵 · Takuya Sugiura🇯🇵

    The interaction between nucleon and charmonia ( and ) is expected to deepen our understanding of various aspects in nonperturbative QCD ranging from the origin of nucleon mass to mass modification in nuclear medium and properties of hidden-charm pentaquark states. Here, we present the low-energy and interactions based on () flavor lattice QCD simulations with nearly physical pion mass MeV. The interactions, extracted from the spacetime correlations of the nucleon and charmonium system by using the HAL QCD method, are found to be attractive in all distances and manifest a characteristic long-range tail consistent with the two-pion exchange interaction. The resulting scattering lengths are around fm, fm and fm for with spin , with spin , and , respectively. Our results are orders of magnitude larger than those from the photoproduction experiments assuming the vector meson dominance.

    Comments:
    9 pages, 3 figures, contribution to the 41st International Symposium on Lattice Field Theory (Lattice 2024), 28 July - 3 August 2024, Liverpool, UK
    Subjects:
    High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
    arXiv:
    2502.00054 [pdf]
    PoS(2025)·4 citations
  8. 08

    [Submitted on 1 Feb 2025] (cross-list from hep-lat)

    Transverse force distributions in the proton from lattice QCD

    K. U. Can🇦🇺 · J. A. Crawford🇦🇺 · R. Horsley🇬🇧 · P. E. L. Rakow🇬🇧 · G. Schierholz🇩🇪 · H. Stüben🇩🇪 · R. D. Young🇦🇺 · J. M. Zanotti🇦🇺

    Single-spin asymmetries observed in polarised deep-inelastic scattering are important probes of hadron structure. The Sivers asymmetry provides information about the transverse momentum of the struck quark and can be related to final-state interactions. Understanding these asymmetries at the quark level has been the subject of much interest in QCD phenomenology. In this contribution, we present a lattice QCD calculation of the transverse spatial distribution of a colour-Lorentz force acting on the struck quark in a proton. Our lattice calculations employ flavours of dynamical fermions at the SU(3) symmetric point across three lattice spacings. We determine a central, spin-independent confining force, as well as spin-dependent force distributions with local forces larger than the QCD string tension. These distributions offer a new, complimentary picture that underlies the Sivers asymmetry in transversely polarised deep-inelastic scattering.

    Comments:
    11 pages, 4 figures, talk presented at the 41st International Symposium on Lattice Field Theory (Lattice2024), July 28th - August 3rd, 2024, Liverpool, UK
    Subjects:
    High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    2502.00325 [pdf]
    PoS(2025)·0 citations
  9. 09

    [Submitted on 1 Feb 2025] (cross-list from cond-mat.quant-gas)

    Fractional vorticity, Bogomol'nyi-Prasad-Sommerfield systems and complex structures for the (generalized) spinor Gross-Pitaevskii equations

    Fabrizio Canfora🇨🇱 · Pablo Pais🇨🇱

    The (generalized) Gross-Pitaevskii equation (GPE) for a complex scalar field in two spatial dimensions is analyzed. It is shown that there is an infinite family of self-interaction potentials which admit Bogomol'nyi-Prasad-Sommerfield (BPS) bounds together with the corresponding first-order BPS systems. For each member of this family, the solutions of the first-order BPS systems are automatically solutions of the corresponding second-order generalized GPE. The simplest topologically non-trivial solutions of these first-order BPS systems describe configurations with quantized fractional vorticity. The corresponding fraction is related to the degree of non-linearity. The case in which the self-interaction potential is of order six (namely , which is a relevant theory both in relativistic quantum field theories in dimensions in connection with the quantum Hall effect as well as in the theory of the supersolids) is analyzed in detail. Such formalism can also be extended to the case of quantum mixtures with multi-component GPEs. The relationship between these techniques and supersymmetry will be discussed. In particular, despite several common features, we will show that there are multi-component GPEs that are not supersymmetric (at least, not in the standard sense) and possess a BPS system of the above type.

    Comments:
    24 pages, 1 Figure. A discussion on the restrictions imposed by the existence of a first-order BPS system on the coupling of the theory has been included
    Subjects:
    Quantum Gases (cond-mat.quant-gas); High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
    arXiv:
    2502.00578 [pdf]
    NPB(2025)·8 citations
  10. 10

    [Submitted on 2 Feb 2025] (cross-list from nucl-ex)

    Double-beta decay of Nd to excited levels of Sm

    A.S. Barabash🇺🇸 · P. Belli🇮🇹 · R. Bernabei🇮🇹 · R.S. Boiko🇺🇦 · F. Cappella🇮🇹 · V. Caracciolo🇮🇹 · R. Cerulli🇮🇹 · F.A. Danevich🇮🇹 · D.L. Fang🇨🇳 · F. Ferella🇮🇹 · A. Incicchitti🇮🇹 · V.V. Kobychev🇺🇦 and 14 other authors

    The decay of Nd to the first excited 740.5 keV level of Sm was measured over 5.845 yr with the help of a four-crystal low-background HPGe spectrometry system in the underground low-background laboratory STELLA of LNGS-INFN. A 2.381 kg highly purified Nd-containing sample was employed as the decay source. The expected de-excitation gamma-quanta of the level with energies 334.0 keV and 406.5 keV were observed both in one-dimensional spectrum and in coincidence data resulting in the half-life yr. Interpreting an excess of the 334.0-keV peak area as an indication of the decay of Nd to the 334.0 keV excited level of Sm with a half-life of yr, the half-life of Nd for the transition to the 0 level is yr, in agreement with the previous experiments. Both half-life values reasonably agree with the theoretical calculations in the framework of proton-neutron QRPA with isospin restoration combined with like nucleon QRPA for description of excited states in the final nuclei. For and transitions of Nd and Nd to several excited levels of Sm and Sm, limits were set at level of yr.

    Comments:
    61 pages, 19 figures, 14 tables
    Subjects:
    Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
    arXiv:
    2502.00748 [pdf]
    EPJC(2025)·5 citations
  11. 11

    [Submitted on 3 Feb 2025] (cross-list from hep-lat)

    Out-of-equilibrium Chiral Magnetic Effect via Kubo formulas

    B. B. Brandt🇩🇪 · G. Endrődi🇩🇪 · E. Garnacho-Velasco🇩🇪 · G. Markó🇩🇪 · A. D. M. Valois🇩🇪

    In this proceedings article, we present the first steps towards the determination of the out-of-equilibrium conductivity of the Chiral Magnetic Effect (CME) in the presence of strong interactions. Using linear response theory, we obtain an analytical expression for the spectral function associated with this effect at one-loop in perturbation theory. In addition, we provide a first estimate of the CME conductivity by calculating the associated Euclidean correlator using quenched Wilson fermions and dynamical staggered fermions in physical Quantum Chromodynamics (QCD) simulations. In particular, we focus on the midpoint of the correlator, which can be used as a proxy of the full conductivity. We present results in a wide range of temperatures, showing how this observable is suppressed at low temperatures, while at high temperatures it approaches the perturbation theory prediction.

    Comments:
    10 pages, 3 figures, contribution to the 41st International Symposium on Lattice Field Theory (LATTICE2024), 28 July - 3 August 2024, Liverpool, UK
    Subjects:
    High Energy Physics — Lattice (hep-lat); High Energy Physics — Experiment (hep-ex); High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
    arXiv:
    2502.01155 [pdf]
    PoS(2025)·10 citations
  12. 12

    [Submitted on 3 Feb 2025] (cross-list from cond-mat.supr-con)

    Renormalization-group approach to the Kohn-Luttinger superconductivity: Amplification of the pairing gap from to

    Yuki Fujimoto🇯🇵

    We revisit the renormalization group (RG) analysis of the Kohn-Luttinger (KL) mechanism for superconductivity. The KL mechanism leads to superconductivity in a system with a repulsive bare interaction. The key ingredient is the screening effect that renders the induced interaction attractive in channels with nonzero angular momentum , thereby triggering the Bardeen-Cooper-Schrieffer (BCS) instability. According to the original argument, the resulting gap is exponentially small, with its exponent scaling as . However, the KL mechanism was originally formulated within perturbation theory, where the series is known to converge poorly in certain cases -- most notably, for the p-wave paring gap induced by a repulsive s-wave contact interaction. This poor convergence may be attributed to a divergent integrand in a specific class of diagrams containing both the BCS logarithm and the Kohn anomaly, suggesting that one must resum the Kohn anomaly contributions separately from the BCS logarithm. In this work, we incorporate the Kohn anomaly contribution into the beta function of the RG equation governing the BCS instability near the Fermi surface. Our solution shows that the KL gap exponent is then proportional to , indicating a significant enhancement of the KL mechanism beyond the previously known result. To illustrate this, we study the spin-triplet p-wave pairing gap arising from a repulsive s-wave contact interaction and compare our RG-based results with those obtained from the Bethe-Salpeter equation in perturbation theory.

    Comments:
    18 pages, 4 figures; v2: published version. minor elaboration
    Subjects:
    Superconductivity (cond-mat.supr-con); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    2502.01169 [pdf]
    PRB(2025)·3 citations
  13. 13

    [Submitted on 3 Feb 2025] (cross-list from hep-ph)

    Constraining the CME in AVFD-simulated heavy-ion collisions using the Sliding Dumbbell Method

    Jagbir Singh🇮🇳 · Anjali Sharma🇮🇳 · Ankita Nain🇮🇳 · Madan M. Aggarwal🇮🇳

    The Anomalous Viscous Fluid Dynamics (AVFD) framework is utilized to generate , , and collision events at = 200 GeV to investigate the Chiral Magnetic Effect (CME). The CME signal is modulated through the axial charge per entropy density () in each event to produce data sets with varying CME signal strengths. Additionally, a 33 local charge conservation (LCC) is implemented in each event. These data sets are analyzed using CME-sensitive two- and three-particle correlators. Furthermore, the Sliding Dumbbell Method (SDM) is employed to identify potential CME-like events within each data set. The identified events selected using the SDM exhibit characteristics consistent with CME. The CME fraction in these events is quantified while accounting for background contributions.

    Comments:
    13 Pages, 10 Figures and 2 Table
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    2502.01195 [pdf]
    EPJA(2026)·0 citations
  14. 14

    [Submitted on 3 Feb 2025] (cross-list from hep-th)

    Quasinormal modes of nonthermal fixed points

    Matisse De Lescluze🇧🇪 · Michal P. Heller🇧🇪

    Quasinormal modes play a prominent role in relaxation of diverse physical systems to equilibria, ranging from astrophysical black holes to tiny droplets of quark-gluon plasma at RHIC and LHC accelerators. We propose that a novel kind of quasinormal modes govern the direct approach to self-similar time evolution of nonthermal fixed points, whose relevance ranges from high energy physics to cold atom gases. We utilize black hole perturbation theory techniques to compute the spectrum of these far from equilibrium quasinormal modes for a kinetic theory with a Focker-Planck collision kernel in isotropic and homogeneous states. Our conclusion is that quasinormal modes of nonthermal fixed points give rise to a tower of progressively more decaying power-law contributions. A byproduct of our analysis is a precise determination and improved understanding of the distribution function characterizing nonthermal fixed points.

    Comments:
    12 pages, 8 figures
    Subjects:
    High Energy Physics — Theory (hep-th); Quantum Gases (cond-mat.quant-gas); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    2502.01622 [pdf]
    PRL(2025)·12 citations

Affiliations

first authorsco-authorsvia INSPIRE