Nuclear Theory·nucl-th

Friday·July 14, 2023

11 papers—9 primary·2 cross-listed

01
What is ab initio?
R. Machleidt
Microscopic nuclear theory is based on the tenet that atomic nuclei can be accurately described as collections of point-like nucleons interacting via two- and many-body forces obeying nonrelativistic quantum mechanics -- and the concept of the ab initio approach is to calculate nuclei accordingly. The forces are fixed in free-space scattering and must be accurate. We will critically review the history of this approach from the early beginnings until today. An analysis of current ab initio calculations reveals that some mistakes of history are being repeated today. The ultimate goal of nuclear theory are high-precision ab initio calculations which, as it turns out, may be possible only at the fifths order of the chiral expansion. Thus, for its fulfillment, nuclear theory is still facing an enormous task.
nucl-thnucl-exFew Body Syst.(2023)·28 citations
02
$Ω^{-}$ production as a probe of equation of state of dense matter near the QCD phase transition in relativistic heavy-ion collisions
Zhi-Min Wu🇨🇳 · Gao-Chan Yong🇨🇳
The production of doubly strange hyperon $Ξ^{-}$ and trebly strange hyperon $Ω^{-}$ in relativistic Au+Au collisions at $s_{N N}$ = 4.2 GeV is explored based on a relativistic transport model that is interweaved with hadronic mean-field potentials for heavy-ion collisions. Upon comparison, it appears that relative to the double strangeness observable $Ξ^{-}$ , the yield and collective flows of the triple strange $Ω^{-}$ exhibit a higher sensitivity to the equation of state (EoS) of dense matter. This characteristic makes the $Ω^{-}$ an essential observable for studying the properties of densely formed matter in relativistic heavy-ion collisions.
nucl-thhep-phnucl-exPRC(2024)·1 citation
03
The study of hadronic rescattering on $K^{* 0}$ resonance yield in baryon-rich QCD matter
Aswini Kumar Sahoo🇮🇳 · Subhash Singha🇨🇳 · Md. Nasim🇮🇳
The effect of hadronic rescattering on $K^{* 0}$ resonance yield can be studied by measuring $K^{* 0} / K$ ratio as a function of centrality or multiplicity. This study investigates how the size of the system and the chemical composition (meson-meson versus meson-baryon interaction) of the matter formed in heavy-ion collisions impact the process of hadronic rescattering. It is shown that existing calculation of $K^{* 0} / K$ ratio, which considers the interaction of $K^{* 0}$ and $K$ mesons with only light mesons in the hadronic medium (neglecting interactions with baryons), fails to explain the measured $K^{* 0} / K$ ratio at RHIC BES energies. To understand the multiplicity dependence of the $K^{* 0} / K$ ratio at RHIC BES and SPS energies ( $s_{N N}$ $<$ 20 GeV), the Ultra Relativistic Quantum Molecular Dynamics (UrQMD) model is employed. UrQMD calculations suggest that for a given multiplicity, $K^{* 0} / K$ is more suppressed in Au+Au collision at $s_{N N}$ =7.7 GeV, compared to that in $s_{N N}$ =200 GeV. This is possibly because of formation different type of QCD medium at 200 GeV and 7.7 GeV, and change in interaction cross-section between hadrons with change in particle type and energy.
nucl-thhep-phnucl-exJ.Phys.G(2025)·12 citations
04
Fingerprints of the triaxial deformation from energies and $B (E 2)$ transition probabilities of $γ$ -bands in transitional and deformed nuclei
S.P. Rouoof · Nazira Nazir · S. Jehangir · G.H. Bhat · J.A. Sheikh · N. Rather · S. Frauendorf
The energies and $B (E 2)$ transitions involving the states of the ground- and $γ$ -bands in thirty transitional and deformed nuclei are calculated using the triaxial projected shell model (TPSM) approach. Systematic good agreement with the existing data substantiates the reliability of the model predictions. The Gamma-rotor version of the collective Bohr Hamiltonian is discussed in order to quantify the classification with respect to the triaxial shape degree of freedom. The pertaining criteria are applied to the TPSM results and the staggering of the energies of the $γ$ -bands is analyzed in detail. An analog staggering of the intra- $γ$ $B (E 2, I \to I - 2)$ is introduced for the first time. The emergence of the staggering phenomena in the transitions is explained in the terms of interactions between the bands.
nucl-thnucl-exEPJA(2024)·26 citations
05
Chiral magnetovortical instability
Shuai Wang🇨🇳 · Xu-Guang Huang🇨🇳
We demonstrate that in a chiral plasma subject to an external magnetic field, the chiral vortical effect can induce a new type of magnetohydrodynamic instability which we refer to as the {\it chiral magnetovortical instability}. This instability arises from the mutual evolution of the magnetic and vortical fields. It can cause a rapid amplification of the magnetic fields by transferring the chirality of the constituent particles to the cross helicity of the plasma.
nucl-thastro-ph.HEhep-phphysics.flu-dyn+1PRD(2024)·11 citations
06
Proton and Neutron Pairing Properties within a mixed volume-surface pairing force using SKI3-HFB Theory
Malik A. Hasan · Ali H. Taqi
This work aims at a systematic investigations of the pairing properties and Fermi properties from the proton drip-line to the neutron drip-line. In order to provide more accurate mass formula with skyrme SKI3 force, the global descriptive power of the SKI3-HFB model for pairing properties are made in this study. Systematic Skyrme SKI3-Hartree-Fock-Bogoliubov calculations with a mixed volume-surface pairing force are carried out to study the ground-state neutron and proton pairing gap, neutron and proton pairing energy and neutron and proton Fermi energy for about 2095 even-even nuclei ranging from $2 \leq Z \leq 110$ to $2 \leq N \leq 236$ . The calculated results of neutron and proton pairing gap are compared with experimental data using the difference-point formulas $Δ^{(3)}, Δ^{(4)}$ and $Δ^{(5)}$ , and also compared with the neutron and proton pairing gap of Lipkin-Nogami model. It is shown that the Skyrme-SKI3 functional with the mixed volume-surface pairing force can be successfully used for describing the ground-state pairing and Fermi properties of the investigated nuclei, in particularly the neutron-rich nuclei and the exotic nuclei near the neutron drip-line. On the other hand, the calculated neutron and proton pairing gap are in good agreement with the available experimental values of the neutron and proton pairing gap of the difference-point formulas $Δ^{(3)}, Δ^{(4)}$ and $Δ^{(5)}$ and with the data of Lipkin-Nogami model over the whole nuclear chart.
nucl-thUkr.J.Phys.(2023)·0 citations
07
Nature of the $N^{*}$ and $Δ$ resonances via coupled-channel dynamics
Yu-Fei Wang🇩🇪 · Ulf-G. Meißner🇩🇪 · Deborah Rönchen🇩🇪 · Chao-Wei Shen🇩🇪
This work aims at determining the composition of certain $N^{*}$ and $Δ$ resonances, i.e. whether they are compact states formed directly by quarks and gluons, or hadronic molecules generated from the meson-baryon interaction. The information of the resonance poles is provided by a comprehensive coupled-channel approach, the Jülich-Bonn model. $13$ states that are significant in this approach are studied. Two criteria for each state are adopted in this paper, the comparison thereof roughly indicates the model uncertainties. It is found that the conclusions for $8$ resonances are relatively certain: $N (1535) \frac{1}{2}^{-}$ , $N (1440) \frac{1}{2}^{+}$ , $N (1710) \frac{1}{2}^{+}$ , and $N (1520) \frac{3}{2}^{-}$ tend to be composite; whereas $N (1650) \frac{1}{2}^{-}$ , $N (1900) \frac{3}{2}^{+}$ , $N (1680) \frac{5}{2}^{+}$ , and $Δ (1600) \frac{3}{2}^{+}$ tend to be compact.
nucl-thhep-phPRC(2024)·21 citations
08
Simultaneous calculation of elastic scattering, fusion, and direct cross sections for reactions of weakly-bound projectiles
H. M. Maridi · N. Keeley · K. Rusek
Simultaneous analyses are performed for cross section data of elastic scattering, fusion, Coulomb breakup, and other direct yields for the $^{6}$ He+ $^{209}$ Bi system at near-Coulomb-barrier energies. The bare and dynamical polarization potentials are constructed microscopically from the structure of the colliding nuclei and they reproduce all the data well with only one adjustable parameter. This method of calculation can be successfully applied to the reactions of weakly-bound and exotic projectiles with heavy targets.
nucl-thPRC(2024)·1 citation
09
Exploring the Macroscopic Properties and Nonradial Oscillations of Proto-Neutron Stars: Effects of Temperature, Entropy, and Lepton Fraction
Sayantan Ghosh🇮🇳 · Shahebaj Shaikh🇮🇳 · Probit J Kalita🇮🇳 · Pinku Routaray🇮🇳 · Bharat Kumar🇮🇳 · B.K. Agrawal🇮🇳
Neutron stars (NSs) have traditionally been viewed as cold, zero-temperature entities. However, recent progress in computational methods and theoretical modelling has opened up the exploration of finite temperature effects, marking a novel research frontier. This study examines Proto-Neutron Stars (PNSs) using the BigApple parameter set to investigate their macroscopic properties. Two approaches are employed: one with constant temperatures (10-50 MeV) and the other fixing entropy per baryon (S) at predefined levels (S = 1 and S = 2). Notably, S remains constant with increasing baryon density due to electron-positron pair formation at finite temperatures. Analysis of PNS mass-radius profiles, considering neutrino trapping and temperature effects, reveals flattened curves and expanded radii with increasing temperature, resulting in slightly higher masses compared to zero temperature. The influence of lepton fraction ( $Y_{l}$ ) on maximum PNS mass is explored, indicating that higher $Y_{l}$ values lead to a softer Equation of State (EoS), reducing maximum mass and increasing the canonical radius ( $R_{1.4}$ ). Further investigation of a constant entropy EoS demonstrates that higher entropy is associated with increased maximum PNS masses and flatter mass-radius curves. Central temperature versus maximum mass relationships suggest a correlation between NS mass and temperature. Lastly, we investigate the behaviour of $f$ -mode frequencies in PNS. It reveals that the frequency of these modes decreases with increasing entropy and temperature, reflecting complex thermodynamic interactions within the stars.
nucl-thNPB(2024)·14 citations
10
Photon and neutron production as in-situ diagnostics of proton-boron fusion
B. M. Hegelich · L. Labun · O. Z. Labun · T. A. Mehlhorn
Short-pulse, ultra high-intensity lasers have opened new regimes for studying fusion plasmas and creating novel ultra-short ion beams and neutron sources. Diagnosing the plasma in these experiments is important for optimizing the fusion yield but difficult due to the picosecond time scales, 10s of micron-cubed volumes and high densities. We propose to use the yields of photons and neutrons produced by parallel reactions involving the same reactants to diagnose the plasma conditions and predict the yields of specific reactions of interest. In this work, we focus on verifying the yield of the high-interest aneutronic proton-boron fusion reaction $^{11} B (p, 2 α)^{4} H e$ , which is difficult to measure directly due to the short stopping range of the produced $α$ s in most materials. We identify promising photon-producing reactions for this purpose and compute the ratios of the photon yield to the $α$ yield as a function of plasma parameters. In beam fusion experiments, the $^{11} C$ yield is an easily-measurable observable to verify the $α$ yield. In light of our results, improving and extending measurements of the cross sections for these parallel reactions are important steps to gaining greater control over these laser-driven fusion plasmas.
↳ physics.plasm-phnucl-thLaser Part.Beams(2022)·0 citations
11
Current status and desired accuracy of the isotopic production cross-sections relevant to astrophysics of cosmic rays II. Fluorine to Silicon (and updated LiBeB)
Yoann Génolini🇫🇷 · David Maurin🇫🇷 · Igor V. Moskalenko🇺🇸 · Michael Unger🇩🇪
High-precision cosmic-ray data from ongoing and recent past experiments (Voyager, ACE-CRIS, PAMELA, ATIC, CREAM, NUCLEON, AMS-02, CALET, DAMPE) are being released in the tens of MeV/n to multi-TeV/n energy range. Astrophysical and dark matter interpretations of these data are limited by the precision of nuclear production cross-sections. In Paper I, PRC 98, 034611 (2018), we set up a procedure to rank nuclear reactions whose desired measurements will enable us to fully exploit currently available data on CR Li to N ( $Z = 3 - 7$ ) species. Here we extend these rankings to O up to Si nuclei ( $Z = 8 - 14$ ), also updating our results on the LiBeB species. We also highlight how comprehensive new high precision nuclear data, that could e.g. be obtained at the SPS at CERN, would be a game-changer for the determination of key astrophysical quantities (diffusion coefficient, halo size of the Galaxy) and indirect searches for dark matter signatures.
↳ astro-ph.HEhep-exnucl-exnucl-thPRC(2024)·19 citations

Affiliations

first authorsco-authorsvia INSPIRE