Nuclear Theory·nucl-th

Tuesday·July 1, 2025

15 papers—6 primary·9 cross-listed

01
[Submitted on 27 Jun 2025]
Suppression of genuine tripartition in heavy nuclei: A self-consistent perspective
Yannen Jaganathen · Janusz Skalski
We investigate the ternary fissions of $^{252}$ Cf (spontaneous) and $^{236}$ U (neutron-induced) into medium-mass fragments, as reported by the Dubna group, using the Hartree-Fock plus BCS method with the SLy6 Skyrme interaction. Compared to microscopic-macroscopic methods used so far, this self-consistent approach provides a greater flexibility of nuclear shapes. Our working hypothesis is that the shape evolution proceeds while the system is still mononuclear. The results show that a ternary fission valley emerges for intermediate elongations of the middle fragment, only when its mass is strongly constrained. This ternary mode is dynamically suppressed by the competition with the dominant binary decay channel. This suggests that a description based solely on quantum tunneling through the energy barrier is insufficient to evaluate its probability. To quantify this suppression, we apply a simple Langevin-type model of overdamped motion with constant damping and temperature, supplemented by a basic estimate of quantum tunneling where relevant. Under assumptions expected to yield an upper bound, we find the probability of ternary fission per binary decay to be on the order of $1 0^{- 8} - 1 0^{- 9}$ for $^{252}$ Cf and $1 0^{- 10} - 1 0^{- 11}$ for $^{236}$ U.
Comments:
7 pages, 5 figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2506.22534 [pdf]
PLB(2025)·2 citations
02
[Submitted on 27 Jun 2025]
Quark Phase Space Distributions in Nuclei
Alexis Nikolakopoulos🇺🇸 · Gerald A. Miller🇺🇸
In [PRC 110, 025201], the authors construct a model for nuclear matter which features a quarkyonic phase. A main feature in this model is that the nucleon occupation is strongly reduced at small momenta. Somewhat surprisingly, this result is supported by data for electron scattering from nuclear matter, where a reduction of the cross section consistent with suppression of nucleons with small momenta is seen. Since nuclear matter data are obtained by extrapolation of electron scattering data on increasingly heavier systems, this feature should manifest at least to some degree in heavy nuclei. To check if this is plausible we extend the approach of [PRC 110, 025201] to finite nuclei by considering the nuclear Wigner distribution. We use non-relativistic and relativistic independent particle models to determine the nuclear Wigner distribution, in addition to the local-density approximation (LDA). Phase-space distributions of quarks are obtained as a convolution of the Wigner distribution with a quark momentum distribution. We highlight some properties of the Wigner distribution in spherical systems, which can spoil the interpretation of the quark phase-space distribution as occupation numbers in the Fermi sea. On the other hand, we show that large systems behave essentially like infinite nuclear matter in their interior, and that LDA and full results are quantitatively similar for large A. We then compute the fraction of baryons that would be in a quarkyonic phase in the same sense as in [PRC 110, 025201] for a set of nuclei with mass $12 \leq A \leq 238$ . We find that this fraction systematically tends to a constant at large $A$ . It is hence plausible that the suppression seen in the nuclear matter data is a genuine feature, present in large finite nuclei. This result is counter-intuitive and we discuss possible electron scattering measurements that could rule out this model.
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2506.22670 [pdf]
PRC(2025)·3 citations
03
[Submitted on 28 Jun 2025]
Elliptic flow of charged hadrons in d+Au collisions at $s_{N N} =$ 200 GeV using a multi-phase transport model
Jaideep Tanwar🇮🇳 · Ishu Aggarwal🇮🇳 · Vipul Bairathi🇮🇳 · Lokesh Kumar🇨🇱 · Sonia Kabana🇨🇱
This study presents a comprehensive analysis of the elliptic flow coefficient, $v_{2}$ , for charged hadrons at mid-rapidity in d+Au collisions at $s_{NN} = 200 GeV$ . Utilizing the AMPT model in both default and string melting modes, we examine the dependence of $v_{2}$ on transverse momentum, collision centrality, and particle type. Furthermore, we present $v_{2}$ scaled by participant eccentricity, which indicates a similar level of collectivity across different centrality intervals in d+Au collisions at $s_{NN} = 200 GeV$ within the AMPT-SM model. Our results indicate that the early-stage partonic phase significantly influences $v_{2}$ , as observed by variations in parton scattering cross-section, while the later stage hadronic rescattering shows minimal impact. Comparisons with STAR and PHENIX experimental data show that the AMPT model effectively captures the transverse momentum dependence of $v_{2}$ , underlining the importance of parton scattering mechanisms and the need for careful interpretation of experimental results in asymmetric systems.
Comments:
9 pages, 9 figures, updated as per the published version
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
2506.22721 [pdf]
PRC(2026)·0 citations
04
[Submitted on 28 Jun 2025]
On energy-dependent scaling factor for the charge-changing cross sections of light elements
Z. Hasan · M. Imran · A. A. Usmani · Z. A. Khan
In this study, the scaling factor for $^{28}$ \rm Si + $^{12}$ \rm C charge-changing cross sections (CCCSs) at 90-1296 MeV/nucleon has been used as a basis to introduce the energy dependence in the scaling factor for the light elements. To test the extracted scaling factor, we predict the charge-changing cross sections for $^{7, 9 - 12, 14}$ \rm Be, $^{10 - 15, 17}$ \rm B, $^{11 - 19}$ \rm C, $^{13 - 22}$ \rm N, $^{15 - 24}$ \rm O, and $^{18 - 21, 23 - 26}$ \rm F isotopes at 200-991 MeV/nucleon in the framework of the Glauber model. The calculations use descriptions of nuclei in terms of the Slater determinant involving harmonic oscillator single-particle wave functions, which reproduce the charge radii obtained earlier [Phys. Rev. C {\bf 110} (2024) 014623; {\bf 111} (2025) 064601]. It is found that the theoretical results provide quite a satisfactory explanation of the experimental data in all the cases, and the extracted scaling factor shows systematic energy dependence for the isotopes of a given element. In conclusion, we expect that the present way of finding the scaling factor could be successfully used in the analysis of CCCSs for the elements Z $\leq$ 9 at any desired energy in the range 90-1296 MeV/nucleon. This result may further add that the present work provides a practical scheme for predicting the charge-changing cross sections (and inferring proton radii) of \rm Be-\rm F isotopes, where measurements are scarce.
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2506.22859 [pdf]
NPA(2026)·1 citation
05
[Submitted on 28 Jun 2025]
Quarks in Hadrons and Nuclei Part 1: Quark Structure of Nucleon
G. Musulmanbekov🇷🇺
We propose a semi-empirical quark model of nucleon structure, so-called, Strongly Correlated Quark Model, SCQM, which possess the features of both non-relativistic and relativistic quark models. Based on SU(3) color symmetry it includes the main features of QCD: local gauge invariance, asymptotic freedom, and chiral symmetry breaking. This First Part of the paper is devoted to description of the model, SCQM, and in the forthcoming Second Part we will apply the model to built the nuclear structure. Applied to nuclei, it reveals emergence of the face-centered cubic (FCC) symmetry of the nuclear structure.This symmetry arise from quark-quark correlations leading, in turn, to nucleon-nucleon correlations.
Comments:
18 pages, 15 figures, 21 references
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2506.23027 [pdf]
0 citations
06
[Submitted on 29 Jun 2025]
Half-life of $^{136}$ Xe for neutrinoless double- $β$ decay calculated with effective axial-vector current coupling unified for two-neurtino and neutrinoless double- $β$ decay modes
J. Terasaki🇨🇿 · O. Civitarese🇦🇷
The upper limit on the mass of the Majorana neutrino, extracted from the limits on the nonobservation of the neutrinoless double- $β$ ( $0 ν β β$ ) decay, is hampered by uncertainties in the matrix elements of the transition operators. Recently, we have shown that the values of the effective axial-vector current coupling constants ( $g_{A}^{eff}$ ) for the $0 ν β β$ and the two-neutrino double- $β$ decays are close. This striking result was obtained for the first time by including vertex corrections and two-body currents in these matrix elements. In this letter, we calculate the half-life for the $0 ν β β$ decay ( $T_{1/2}^{0 ν}$ ) of $^{136}$ Xe using this closeness and show the convergence of the half-life with respect to the variation of the method to determine $g_{A}^{eff}$ . The closeness of the $g_{A}^{eff}$ of the two decay modes plays a decisive role in predicting $T_{1/2}^{0 ν}$ . The appropriate value of $g_{A}^{eff}$ depends on the assumptions made for the sectors of the nuclear structure and transition operators of the calculations within the perturbation scheme. The value $g_{A}^{eff} \approx 1$ is obtained when the SkM $^{*}$ is used to describe the nuclear structure component, while a smaller value of $g_{A}^{eff}$ is obtained by applying a less realistic interaction like the SGII one.
Comments:
6 pages, 2 figures, revised; a few paragraphs added
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
2506.23239 [pdf]
PRC(2025)·1 citation
07
[Submitted on 27 Jun 2025] (cross-list from hep-lat)
Lattice study of correlators for quarkonium decay
Saumen Datta🇮🇳 · Debasish Banerjee🇬🇧 · Nora Brambilla🇩🇪 · Marc Janer🇩🇪 · Viljami Leino🇩🇪 · Julian Mayer-Steudte🇩🇪 · Peter Petreczky🇺🇸 · Balbeer Singh🇺🇸 · Antonio Vairo🇩🇪
While there has been a lot of progress in developing a formalism for the study of quarkonia in QGP, a nonperturbative study is still difficult. For bottomonia, where the system size is much less than the inverse temperature, the interaction of the system with the medium can be approximated by a dipole interaction with the color electric field. The decay of the quarkonia can be connected to a correlation function of the color electric field. We present preliminary results from a lattice study of the relevant color electric field correlator. The structure of the correlator, and its difference from the corresponding correlator studied for heavy quark diffusion, is discussed.
Comments:
5 pages, 3 figures. Contribution to ATHIC 2025
Subjects:
High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2506.22594 [pdf]
J.Subatomic Part.Cosmol.(2025)·0 citations
08
[Submitted on 28 Jun 2025] (cross-list from astro-ph.HE)
The diffuse supernova neutrino background: an update with modern population synthesis and core-collapse simulations
Cecilia Lunardini🇺🇸 · Tomoya Takiwaki🇯🇵 · Tomoya Kinugawa🇯🇵 · Shunsaku Horiuchi🇯🇵 · Kei Kotake🇯🇵
We present a new, state-of-the-art computation of the Diffuse Supernova Neutrino Background (DSNB), where we use neutrino spectra from multi-dimensional, multi-second core collapse supernova simulations - including both neutron-star and black-hole forming collapses - and binary evolution effects from modern population synthesis codes. Large sets of numerical results are processed and connected in a consistent manner, using two key quantities: the mass of the star's Carbon-Oxygen (CO) core at an advanced pre-collapse stage - which depends on binary evolution effects - and the compactness parameter, which is the main descriptor of the post-collapse neutrino emission. The method enables us to model the neutrino emission of a very diverse, binary-affected population of stars, which cannot unambiguously be mapped in detail by existing core collapse simulations. We find that including black hole-forming collapses enhances the DSNB by up to 50% at energies greater than 30-40 MeV. Binary evolution effects can change the total rate of collapses and generate a sub-population of high core mass stars that are stronger neutrino emitters. However, the net effect on the DSNB is moderate - up to a 15% increase in flux - due to the rarity of these super-massive cores and to the relatively modest dependence of the neutrino emission on the CO core mass. The methodology presented here is suitable for extensions and generalizations, and therefore it lays the foundation for modern treatments of the DSNB.
Comments:
LaTeX, 17 pages, 7 figures. Version accepted in Physical Review D. Title modified per referee suggestion, text expanded. A plotting error has been corrected in fig. 6. Conclusions unchanged. Data in fig. 6 are available at https://doi.org/10.5281/zenodo.15876032
Subjects:
High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2506.22699 [pdf]
PRD(2026)·6 citations
09
[Submitted on 28 Jun 2025] (cross-list from hep-ph)
Study on Pentaqaurks by Solving Schrodinger Equation in the Non-Hermitian Quantum Mechanics
Bao-Xi Sun🇨🇳
The interaction of the charmed baryon and the anticharmed meson is assumed to be realized by exchanging a scalar meson of $f_{0} (500)$ , and then these systems are studied by solving the Schrodinger equation, respectively. When the pentaquarks $P_{c c ˉ} (4312)^{+}$ , $P_{c c ˉ} (4457)^{+}$ , $P_{c c ˉ s} (4338)^{0}$ , and $P_{c c ˉ s} (4459)^{0}$ are treated as $Σ_{c} D ˉ$ , $Σ_{c} D ˉ^{*}$ , $Ξ_{c} D ˉ$ and $Ξ_{c} D ˉ^{*}$ bound states, four resonance states of them are obtained as solutions of the Schrodinger equation under the outgoing wave condition, respectively. The resonance state of $Σ_{c} D ˉ$ might correspond to the particle $P_{c c ˉ} (4440)^{+}$ , while the other three resonance states have no counterparts in the review of the Particle Data Group(PDG). Although the binding energy of the bound state is only several MeVs, all these resonance states are more than 100 MeV higher than their corresponding thresholds, respectively. The calculation results indicate that the spectrums of the strange and non-strange pentaquarks are symmetric to each other.
Comments:
16 pages, 5 figures and 4 tables
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2506.22723 [pdf]
0 citations
10
[Submitted on 28 Jun 2025] (cross-list from hep-lat)
A generalized definition of the isothermal compressibility in (2+1)-flavor QCD
D. A. Clarke🇺🇸 · J. Goswami🇩🇪 · F. Karsch🇩🇪 · P. Petreczky🇺🇸
We introduce a generalized definition of the isothermal compressibility ( $κ_{T, σ_{Q}^{2}}$ ) calculable by keeping net conserved charge fluctuations rather than total number densities constant. We present lattice QCD results for this isothermal compressibility, expressed in terms of fluctuations of conserved charges that are related to baryon ( $B$ ), electric charge ( $Q$ ) and strangeness ( $S$ ) quantum numbers. This generalized isothermal compressibility is compared with hadron resonance gas model calculations as well as with heavy-ion collision data obtained at RHIC and the LHC. We find $κ_{T, σ_{Q}^{2}} = 13.8 (1.3)$ ~fm $^{3}$ /GeV at $T_{p c, 0} = 156.5 (1.5)$ ~MeV and $μ^_{B} = 0$ . This finding is consistent with the rescaled result of the ALICE Collaboration, where we replaced the number of charged hadrons ( $N_{ch}$ ) by the total number of hadrons ( $N_{tot}$ ) at freeze-out. Normalizing this result with the QCD pressure ( $P$ ) we find that the isothermal compressibility on the pseudo-critical line stays close to that of an {\it ideal gas}, {\it i.e.} $P κ_{T, σ_{Q}^{2}} ≃ 1$ .
Comments:
6 pges, 4 figures
Subjects:
High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2506.22816 [pdf]
PRD(2026)·3 citations
11
[Submitted on 29 Jun 2025] (cross-list from nucl-ex)
Direct proton transfer on $^{46}$ Ar supports the presence of a charge density bubble linked to a novel nuclear structure below $^{48}$ Ca
Daniele Brugnara (1,2)🇮🇹 · Andrea Gottardo (2)🇮🇹 · Marlene Assiè (3)🇫🇷 · Carlo Barbieri (4,5)🇮🇹 · Daniele Mengoni (1,6)🇮🇹 · Didier Beaumel (3)🇫🇷 · Stefano Brolli (4,5)🇮🇹 · Simone Bottoni (4,5)🇮🇹 · Emmanuel Clément (7)🇫🇷 · Gianluca Colò (4,5)🇮🇹 · Freddy Flavigny (8)🇫🇷 · Franco Galtarossa (3,6)🇫🇷 and 67 other authors
The $^{46}$ Ar( $^{3}$ He,d) $^{47}$ K reaction was performed in inverse kinematics using a radioactive $^{46}$ Ar beam produced by the SPIRAL1 facility at GANIL and a cryogenic $^{3}$ He target. The AGATA-MUGAST-VAMOS setup allowed the coincident measurement of the $γ$ rays, deuterons and recoiling $^{47}$ K isotopes produced by the reaction. The relative cross sections towards the proton-addition states in $^{47}$ K point towards a depletion of the $π s_{1/2}$ shell. The experimental findings are in good agreement with ab initio calculations, which predict that $^{46}$ Ar exhibits a charge density bubble associated with a pronounced proton closed-shell character.
Subjects:
Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2506.23228 [pdf]
1 citation
12
[Submitted on 30 Jun 2025] (cross-list from hep-ph)
Collective phenomena in chirally imbalanced medium
Sourav Duari🇮🇳 · Nilanjan Chaudhuri🇮🇳 · Sourav Sarkar🇮🇳 · Pradip Roy🇮🇳
We calculate the gluon polarization tensor for a chirally imbalanced plasma using hard thermal loop approximation in the real time formulation of thermal field theory. The dispersion relations obtained from the poles of the effective gluon propagator are solved numerically as well as analytically in appropriate limiting cases. It is seen that the degenerate transverse modes split into left and right handed circularly polarized modes. We also compute imaginary poles of the propagator which signal the presence of instability in the plasma. Relevant time scales for development of such instabilities are discussed in detail. Furthermore, we compute both the real and imaginary parts of the static heavy-quark potential in the chirally imbalanced plasma and argue that quarkonium suppression is enhanced due to the combined effects of a reduced debye screening length and an increased decay width. In addition, we calculate the gluon spectral density, sum rules and residues for various cases, providing a comprehensive understanding of the collective behaviour of the medium.
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2506.23646 [pdf]
EPJA(2025)·5 citations
13
[Submitted on 30 Jun 2025] (cross-list from hep-ph)
Nucleon mass: trace anomaly and $σ$ -terms
Martin Hoferichter🇨🇭 · Jacobo Ruiz de Elvira🇪🇸
We give a pedagogical introduction to the origin of the mass of the nucleon. We first review the trace anomaly of the energy-momentum tensor, which generates most of the nucleon mass via the gluon fields and thus contributes even in the case of vanishing quark masses. We then discuss the contributions to the nucleon mass that do originate from the Higgs mechanism via the quark masses, reviewing the current status of nucleon $σ$ -terms that encode the corresponding matrix elements.
Comments:
12 pages, 1 figure, version to be published in the Encyclopedia of Particle Physics
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
arXiv:
2506.23902 [pdf]
Encyclopedia of Particle Physics·7 citations
14
[Submitted on 30 Jun 2025] (cross-list from quant-ph)
Finite Gaussian assistance protocols and a conic metric for extremizing spacelike vacuum entanglement
Boyu Gao🇺🇸 · Natalie Klco🇺🇸
In a pure Gaussian tripartition, a range of entanglement between two parties ( $A B$ ) can be purified through classical communication of Gaussian measurements performed within the third ( $C$ ). To begin, this work introduces a direct method to calculate a hierarchic series of projective $C$ measurements for the removal of any $A B$ Gaussian noise, circumventing divergences in prior protocols. Next, a multimode conic framework is developed for pursuing the maximum (Gaussian entanglement of assistance, GEOA) or minimum (Gaussian entanglement of formation, GEOF) pure entanglement that may be revealed or required between $A B$ . Within this framework, a geometric necessary and sufficient entanglement condition emerges as a doubly-enclosed conic volume, defining a novel distance metric for conic optimization. Extremizing this distance for spacelike vacuum entanglement in the massless and massive free scalar fields yields (1) the highest known lower bound to GEOA, the first that decays slower than the two-point correlation functions and (2) the lowest known upper bound to GEOF, the first that decays exponentially mirroring the mixed $A B$ negativity. Furthermore, combination of the above with a generalization of previous partially-transposed noise filtering techniques allows calculation of a single $C$ measurement that maximizes the purified $A B$ entanglement. Beyond expectation that these behaviors of spacelike GEOA and GEOF persist in interacting theories, the present measurement and optimization techniques are applicable to physical many-body Gaussian states beyond quantum fields.
Comments:
36 pages, 8 figures, 3 appendices; revised discussion in section 3.B
Subjects:
Quantum Physics (quant-ph); High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
arXiv:
2506.23968 [pdf]
PRA(2026)·1 citation
15
[Submitted on 30 Jun 2025] (cross-list from hep-ph)
Quark Recombination
Rainer J. Fries · Vincenzo Greco · Ralf Rapp
Hadronization is a fundamental process occurring at a distance scale of about $1 fm ≃ Λ_{QCD}^{- 1}$ , hence within non-perturbative dynamics. In elementary collisions, like $e^{+} e^{-}$ , $e^{-} p$ , or $pp$ , phenomenological approaches to hadronization have been developed based on vacuum-like dynamics that require the creation of quark-antiquark and/or diquark pairs during the hadronization process. In the 2000s, the idea was developed that in ultra-relativistic nucleus-nucleus (AA) collisions, which lead to the formation of a partonic medium with large (anti-)quark densities, hadronization can occur through the recombination of in-medium quarks, unlike the situation in $e^{+} e^{-}$ , $e^{-} p$ , and $pp$ . We give an overview of the main features that characterize quark recombination and have enabled a description of several important experimental observables at both RHIC and LHC over the last two decades. We highlight some additional developments and open issues. We specifically discuss the impact of coalescence on the study of heavy-flavor hadronization, including recent developments showing signatures of (the onset of) quark coalescence even in $pp$ collisions at TeV energies. Furthermore, we highlight specific features of hadronization for quarkonium in AA collisions, where it has been possible to develop a dynamical kinetic approach that allows to extract more detailed information about the temperature dependence of the heavy-quark interaction in hot QCD matter.
Comments:
31 pages, 10 figures,Contribution to "Quark Gluon Plasma at Fifty - A Commemorative Journey", Publisher: Springer Nature Switzerland AG, Editors: Tapan Nayak, Marco Van Leeuwen, Steffen Bass, James Dunlop
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2506.24023 [pdf]
6 citations

Affiliations

first authorsco-authorsvia INSPIRE