Nuclear Theory·nucl-th

Tuesday·January 7, 2025

16 papers—12 primary·4 cross-listed

01
[Submitted on 28 Dec 2024]
Nuclear EoS with finite range interaction and the Constrained Dynamics
Massimo Papa
The effects of the many-body correlations with respect the MF description characterizing the Constrained Molecular Dynamics are discussed in the case of finite and zero range effective microscopic interactions. In particular, for the system $^{64} N i +^{48} C a$ fusion-fission cross-sections, IMF production and transversal flow have been evaluated in the framework of the CoMD model at different incident energies. The results obtained significantly depend on whether the effects of the above-mentioned correlations are taken into account in the corresponding EoS.
Comments:
arXiv admin note: substantial text overlap with arXiv:2309.02878
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2501.01975 [pdf]
Nuovo Cim.C(2025)·0 citations
02
[Submitted on 3 Jan 2025]
Study of medium-mass and heavy hypernuclei produced through spallation and fission reactions in inverse kinematics
J. L. Rodríguez-Sánchez🇪🇸 · J. Cugnon🇧🇪 · J.-C. David🇫🇷 · J. Hirtz🇫🇷 · A. Kelić-Heil🇩🇪
Innovative experiments using the inverse kinematics technique to accelerate light, medium-mass, and heavy nuclei at relativistic energies have become excellent tools to produce and study hypernuclei. In this work, we investigate hypernuclei created in spallation reactions, where multifragmentation, particle evaporation, and fission processes play an important role in the formation of final hypernuclei residues. For the description of spallation reactions, we couple the Liège intranuclear cascade model, extended recently to the strange sector, to a new version of the ablation (ABLA) model that accounts for the evaporation of {\Lambda}-particles from hot hyperremnants produced during the intranuclear cascade stage. These state-of-the art models are then used to study the production of hypernuclei close to the drip lines through spallation-evaporation and fission reactions. Moreover, recent results obtained for the study of hypernuclei dynamics, in particular, for the constraint of the viscosity parameter involved in hyperfission reactions are also presented.
Comments:
2 figures, ARIS2023 proceedings
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2501.02037 [pdf]
0 citations
03
[Submitted on 3 Jan 2025]
Parity-doubled nucleons can rapidly cool neutron stars
Liam Brodie🇺🇸 · Robert D. Pisarski🇺🇸
In confined hadronic matter, the spontaneous breaking and restoration of chiral symmetry can be described by considering nucleons, $N_{+} (939)$ , and excited states of opposite parity, $N_{-} (1535)$ . In a cold, dense hadronic phase where chiral symmetry remains spontaneously broken, direct Urca decay processes involving the $N_{-}$ are possible, e.g. $N_{-} \to N_{+} + e^{-} + ν ˉ_{e}$ . We show that at low temperature and moderate densities, because the $N_{-}$ is much heavier than the $N_{+}$ , such cooling dominates over standard $N_{+}$ direct Urca processes. This provides a strong astrophysical signature of the pattern of chiral symmetry restoration in neutron stars.
Comments:
v2: 8 pages, 3 figures. Published in Phys. Rev. Lett
Subjects:
Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics — Phenomenology (hep-ph)
arXiv:
2501.02055 [pdf]
PRL(2025)·4 citations
04
[Submitted on 5 Jan 2025]
Atmospheric Antideuteron Flux Within a Dynamical Coalescence Approach
Jie Pu🇨🇳 · Xin Li🇨🇳 · Kai-Jia Sun🇨🇳 · Chun-Wang Ma🇨🇳 · Lie-Wen Chen🇨🇳
Cosmic antideuterons are considered as one of the most promising tools for the indirect detection of dark matter due to their ultra-low astrophysical backgrounds. Currently only upper limits on the antideuteron flux exist, but advancements in experimental detection technology may soon lead to positive signals. A major source of background is the production of secondary antideuterons through collisions of cosmic rays with the surrounding medium. In this study, antideuteron production is modeled using a multiphase transport model (AMPT) coupled with a dynamical coalescence model. By applying a widely used leaky box model and incorporating specific processes, we present a new theoretical baseline for atmospheric secondary antideuteron flux, including a tertiary contribution, from primary cosmic rays interacting with Earth's atmosphere. Our results indicate that the atmospheric antideuteron flux are within the range of various existing calculations and remain well below the upper limits set by the Balloon-borne Experiment with a Superconducting Spectrometer (BESS). The atmospheric antideuteron is found to dominate the antideuteron background at kinetic energies below $0.26$ GeV/n.
Comments:
8 pages, 4 figures. Accepted version to appear in JHEP
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
arXiv:
2501.02422 [pdf]
JHEP(2025)·0 citations
05
[Submitted on 5 Jan 2025]
Non-perturbative calculations of nuclear matter using in-medium similarity renormalization group
Xin Zhen🇨🇳 · Rongzhe Hu🇨🇳 · Haoyu Shang🇨🇳 · Jiawei Chen🇨🇳 · Junchen Pei🇨🇳 · Furong Xu🇨🇳
The non-perturbative {\it ab initio} calculations of infinite nuclear matter using In-Medium Similarity Renormalization Group (IMSRG) method is developed in this work, which enables calculations with chiral two and three-nucleon forces at N $^{2}$ LO and N $^{3}$ LO. Results from the many-body perturbation theory at different orders and coupled-cluster theory are also presented for comparison. It is shown that different many-body approaches lead to obvious discrepancies with a harder nuclear interaction for both pure neutron matter and symmetric nuclear matter. This work provides a novel alternative infrastructure for future studies of dense nuclear matter and strongly-correlated many-body systems.
Comments:
8 pages, 6 figures, accepted version for PLB
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2501.02479 [pdf]
PLB(2025)·9 citations
06
[Submitted on 5 Jan 2025]
Evolutions of in-medium baryon-baryon scattering cross sections and stiffness of dense nuclear matter from Bayesian analyses of FOPI proton flow excitation functions
Bao-An Li🇺🇸 · Wen-Jie Xie🇺🇸
Within a Bayesian statistical framework using a Gaussian Process (GP) emulator for an isospin-dependent Boltzmann-Uehling-Uhlenbeck (IBUU) transport model simulator of heavy-ion reactions with momentum-independent Skyrme interactions, we infer from the proton directed and elliptical flow in mid-central Au+Au reactions at beam energies from 150 to 1200 MeV/nucleon taken by the FOPI Collaboration the posterior Probability Distribution Functions (PDFs) of the in-medium baryon-baryon scattering cross section (BBSCS) modification factor $X$ (with respect to their free-space values) and the stiffness parameter $K$ of dense nuclear matter. We find that the most probable value of $X$ evolves from around 0.7 to 1.0 as the beam energy $E_{b e am} / A$ increases. On the other hand, the posterior PDF( $K$ ) may have dual peaks having roughly the same height or extended shoulders at high $K$ values. More quantitatively, the posterior PDF( $K$ ) changes from having a major peak around 220 MeV characterizing a soft EOS in the reaction at $E_{b e am} / A$ =150 MeV to one that peaks around 320 MeV indicating a stiff EOS in the reactions at $E_{b e am} / A$ higher than about 600 MeV. The transition from soft to stiff happens in mid-central Au+Au reactions at beam energies around 250 MeV/nucleon in which $K = 220$ MeV and $K = 320$ MeV are approximately equally probable. Altogether, the FOPI proton flow excitation function data indicate a gradual hardening of hot and dense nuclear matter as its density and temperature increase in reactions with higher beam energies.
Comments:
Added more discussions. Phys. Rev. C in press
Subjects:
Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE); Nuclear Experiment (nucl-ex)
arXiv:
2501.02579 [pdf]
PRC(2025)·11 citations
07
[Submitted on 5 Jan 2025]
Diagrammatic Monte Carlo for Finite Systems at Zero Temperature
Stefano Brolli · Carlo Barbieri · Enrico Vigezzi
High-order virtual excitations play an important role in microscopic models of nuclear reactions at intermediate energies. However, the factorial growth of their complexity has prevented their consistent inclusion in ab initio many-body calculations. For infinite systems at finite temperature, such drawbacks can be overcome using diagrammatic Monte Carlo techniques to resum entire series of Feynman diagrams. We present a diagrammatic Monte Carlo algorithm that can be applied to self-bound systems with discrete energy levels at zero temperature, and demonstrate its potential for the Richardson model of nuclear pairing. We show that sampling the topological space of diagrams allows the inclusion of high-order excitations that are neglected in state-of-the-art approximations used in nuclear physics and quantum chemistry. We propose that sampling the diagrammatic space can overcome the long-standing gap between our microscopic understanding of structure and reactions in nuclear physics.
Comments:
5 pages, 5 figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2501.02646 [pdf]
PRL(2025)·12 citations
08
[Submitted on 6 Jan 2025]
Axial-Vector and Tensor Spin Polarization and Chiral Restoration in Quark Matter
Tomoyuki Maruyama🇯🇵 · Toshitaka Tatsumi🇯🇵
We study spontaneous spin-polarizations of quark matter with flavour $S U (2)$ symmetry at zero temperature in the NJL model. In a relativistic framework, there are two types of the spin-spin interactions: axial-vector (AV) and tensor (T), which accordingly give rise to different types of spin-polarized materials. When the spin-spin interaction is sufficiently strong, the spin-polarized phase emerges within a specific density region. As the spin-spin interaction becomes stronger, this phase extends over higher density region beyond the critical density of chiral restoration in normal quark matter. We show that the spin-polarized phase leads to another kind of the spontaneous chiral symmetry breaking phase.
Comments:
34 pages, 8 figutes
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
arXiv:
2501.02713 [pdf]
Symmetry(2024)·0 citations
09
[Submitted on 6 Jan 2025]
Nuclear Schiff Moments and CP Violation
Jonathan Engel🇺🇸
This paper reviews the calculation of nuclear Schiff moments, which one must know in order to interpret experiments that search for time-reversal-violating electric dipole moments in certain atoms and molecules. After briefly reviewing the connection between dipole moments and CP violation in and beyond the Standard Model of particle physics, Schiff's theorem, which concerns the screening of nuclear electric dipole moments by electrons, Schiff moments, and experiments to measure dipole moments in atoms and molecules, the paper examines attempts to compute Schiff moments in nuclei such as $^{199}$ Hg and octupole-deformed isotopes such as $^{225}$ Ra, which are particularly useful in experiments. It then turns to ab initio nuclear-structure theory, describing ways in which both the In-Medium Similarity Renormalization Group and coupled-cluster theory can be used to compute important Schiff moments more accurately than the less controlled methods that have been applied so far.
Comments:
24 pages, 4 figures, submitted to the Annual Review of Nuclear and Particle Science
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2501.02744 [pdf]
Ann.Rev.Nucl.Part.Sci.(2025)·23 citations
10
[Submitted on 6 Jan 2025]
Extracting the Speed of Sound in Heavy-Ion Collisions: A Study of Quantum-Initiated Fluctuations and Thermalization
Yu-Shan Mu🇨🇳 · Jing-An Sun🇨🇳 · Li Yan🇨🇳 · Xu-Guang Huang🇨🇳
The thermalization of quark-gluon plasma created in heavy-ion collisions is crucial for understanding its behavior as a relativistic fluid and the thermodynamic properties of the Quantum Chromodynamics (QCD). This study investigates the role of fluctuations in the relationship between transverse momentum and particle multiplicity, with a particular focus on their impact on extracting the QCD speed of sound. In a thermalized quark-gluon plasma, these fluctuations mostly originate from quantum fluctuations in the colliding nuclei, and exhibit a Gaussian distribution as a consequence of their independence from thermodynamic response. In contrast, non-thermalized systems display non-Gaussian fluctuations, reflecting the breakdown of thermalization. By leveraging the Gaussianity condition of quantum-initiated fluctuations, the physical value of the speed of sound can be extracted statistically, even in the presence of significant event-by-event fluctuations. This framework provides a robust diagnostic tool for probing thermalization and extracting thermodynamic properties in both large and small collision systems.
Comments:
supplemental file added
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
2501.02777 [pdf]
PRL(2025)·13 citations
11
[Submitted on 6 Jan 2025]
Constraining the chiral magnetic effect using spectator and participant planes across Au+Au and isobar collisions at $s_{_{NN}} = 200$ GeV
Bang-Xiang Chen🇨🇳 · Xin-Li Zhao🇨🇳 · Guo-Liang Ma🇨🇳
We investigate the chiral magnetic effect (CME) in relativistic heavy-ion collisions through an improved two-plane method analysis of the $Δ γ$ observable, probing $C P$ -symmetry breaking in strong interactions and topological properties of the QCD vacuum. Using a multiphase transport model with tunable CME strengths, we systematically compare Au+Au and isobar collisions at $s_{_{NN}} = 200$ GeV. We observe a reduced difference in the CME signal-to-background ratio between the spectator and participant planes for Au+Au collisions compared to isobar collisions. A comprehensive chi-square analysis across all three collision systems reveals stronger CME signatures in Au+Au collisions relative to isobar collisions, particularly when measured with respect to the spectator plane. Our findings demonstrate an enhanced experimental reliability of the two-plane method for the CME detection in Au+Au collisions.
Comments:
15 pages, 17 figures. arXiv admin note: text overlap with arXiv:2301.12076
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
2501.02794 [pdf]
Nucl.Sci.Tech.(2025)·1 citation
12
[Submitted on 6 Jan 2025]
In-medium $Λ N$ interactions with leading order covariant chiral hyperon/nucleon-nucleon forces
Ru-You Zheng🇨🇳 · Zhi-Wei Liu🇨🇳 · Li-Sheng Geng🇨🇳 · Jin-Niu Hu🇨🇳 · Sibo Wang🇨🇳
In-medium $Λ N$ interactions are crucial in hypernuclei and neutron star physics. In this work, we study the in-medium $Λ N$ interaction within the relativistic Brueckner-Hartree-Fock (RBHF) framework, employing the leading-order covariant chiral hyperon/nucleon-nucleon forces for the first time. We demonstrate that a consistent description of both the experimental cross-section data and the `empirical value' of the $Λ$ single-particle potential can be achieved. This contrasts with the majority of studies in the non-relativistic framework, where higher-order two-body chiral forces are typically required. This study offers a new perspective on the in-medium $Λ N$ interactions, urgently needed in relativistic \textit{ab initio} hypernuclear physics studies.
Comments:
9 pages, 5 figures; accepted for publication in Physics Letters B
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2501.02826 [pdf]
PLB(2025)·12 citations
13
[Submitted on 3 Jan 2025] (cross-list from hep-th)
Symmetry and causality constraints on Fermi liquids
Luca V. Delacrétaz🇺🇸 · Subham Dutta Chowdhury🇺🇸 · Umang Mehta🇺🇸
We investigate symmetry and causality constraints on interacting Fermi liquids. Whereas Galilean or Lorentz boost symmetry leads to a well-known constraint on the first Landau parameter $F_{1}$ , we show that scale invariance similarly constrains $F_{0}$ . In the case of conformal Fermi liquids, we show that causality constraints on the particle-hole continuum and on zero sound strongly restrict the available parameter space for interacting Fermi liquids. We also consider nonlinear response, which we show is sensitive to additional ``generalized Landau parameters'' even at lowest orders in the long wavelength limit. We impose Galilean, Lorentz and scale symmetry on these generalized Landau parameters, obtaining further nonlinear constraints. We test our constraints in several microscopic models that enter a Fermi liquid phase.
Comments:
JHEP version, Appendices added, Detailed discussion on Schrodinger invariance in Fermi liquids
Subjects:
High Energy Physics — Theory (hep-th); Strongly Correlated Electrons (cond-mat.str-el); Nuclear Theory (nucl-th)
arXiv:
2501.02073 [pdf]
JHEP(2025)·11 citations
14
[Submitted on 6 Jan 2025] (cross-list from hep-ph)
Valence quark-stopping and gluon junction-stopping scenarios in electron-nucleus collisions at the forthcoming Electron-Ion Collider: Which one is correct?
Ting-Ting Duan🇨🇳 · Fu-Hu Liu🇨🇳 · Khusniddin K. Olimov🇺🇿
In the current literature, two stopping scenarios are being discussed in the context of high-energy collisions: the valence quark scenario and the gluon or baryon junction scenario. In the valence quark-stopping scenario, three valence quarks each contribute one-third of the baryon number within a baryon. Conversely, in the gluon junction-stopping scenario, the gluon junction is responsible for carrying the entire baryon number. At present, there is no consensus regarding which type of stopping scenario is correct. Based on a multi-source thermal model, our investigation indicates that the experimental data analyzed in both previous and present studies suggest that the valence quark-stopping scenario is more suitable for semi-quantitative discussions in high-energy collisions. It is anticipated that this scenario can be further validated through electron-nucleus ( $e A$ ) collisions at the forthcoming Electron-Ion Collider (EIC).
Comments:
19 pages, 9 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2501.02819 [pdf]
0 citations
15
[Submitted on 6 Jan 2025] (cross-list from nucl-ex)
Direct observation of $β$ and $γ$ decay from a high-spin long-lived isomer in $^{187}$ Ta
J. L. Chen · H. Watanabe · P. M. Walker · Y. Hirayama · Y. X. Watanabe · M. Mukai · C. F. Jiao · M. Ahmed · M. Brunet · T. Hashimoto · S. Ishizawa · F. G. Kondev and 11 other authors
$^{187}$ Ta ( $Z = 73$ , $N = 114$ ) is located in the neutron-rich $A \approx 190$ region where a prolate-to-oblate shape transition via triaxial softness is predicted to take place. A preceding work on the $K^{π} = (25/ 2^{-})$ isomer and a rotational band to which the isomer decays carried out by the same collaboration revealed that axial symmetry is slightly violated in this nucleus. This paper focuses on a higher-lying isomer, which was previously identified at 2933(14) keV by mass measurements with the Experimental Storage Ring at GSI. The isomer of interest has been populated by a multi-nucleon transfer reaction with a $^{136}$ Xe primary beam incident on a natural tungsten target, using the KEK Isotope Separation System at RIKEN. New experimental findings obtained in the present paper include the internal and external $β$ -decay branches from the high-spin isomer and a revised half-life of 136(24) s. The evaluated hindrances for $K$ -forbidden transitions put constraints on the spin-parity assignment, which can be interpreted as being ascribed to a prolate shape with a five-quasiparticle configuration by model calculations.
Comments:
9 pages, 5 figures
Subjects:
Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2501.02848 [pdf]
PRC(2025)·2 citations
16
[Submitted on 6 Jan 2025] (cross-list from hep-ph)
Chiral dynamics: Quo vadis?
Ulf-G. Meißner🇩🇪
I review the status of chiral dynamics. Topics include pion-pion scattering, dynamically generated states in the hadron spectrum and the emergence of two-pole structures, chiral symmetry in nuclear physics and chiral dynamics in the Big Bang.
Comments:
14 pages, 4 figures, Special Plenary Session talk at Chiral Dynamics 2024
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:
2501.03014 [pdf]
PoS(2026)·1 citation

Affiliations

first authorsco-authorsvia INSPIRE