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Nuclear Theory·nucl-th

Wednesday·August 23, 2023

9 papers—6 primary·3 cross-listed

All9Primary6Cross-lists3
  1. 01

    [Submitted on 21 Aug 2023]

    Exploring Rapidity-Even Dipolar Flow in Isobaric Collisions at RHIC

    Niseem Magdy🇺🇸 · Roy Lacey🇺🇸

    Employing the AMPT transport model, we investigate the response of the rapidity-even dipolar flow () and its associated Global Momentum Conservation (GMC) parameter to structural disparities within Ru and Zr nuclei. We analyze and collisions at a center-of-mass energy of = 200 GeV. Our analysis demonstrates that the eccentricity , and exhibit subtle yet discernible sensitivity to the input nuclear structure distinctions between Ru and Zr isobars. This observation suggests that measuring and the GMC parameter in these isobaric collisions could serve as a means to fine-tune the comprehension of their nuclear structure disparities and offer insights to enhance the initial condition assumptions of theoretical models.

    Comments:
    7 pages, 6 figures
    Subjects:
    Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
    arXiv:
    2308.11031 [pdf]
    J.Phys.G(2024)·3 citations
  2. 02

    [Submitted on 22 Aug 2023]

    Emerging {\gamma}-soft-like spectrum in 196Pt in the SU3-IBM (I)

    Tao Wang · Bing-cheng He · Chun-xiao Zhou · Dong-kang Li · Lorenzo Fortunato

    Recently, it has been argued that a spherical-like spectrum emerges in the SU3-IBM, opening up new approaches to understand the {\gamma}-softness in realistic nuclei. In a previous paper, {\gamma}-softness with degeneracy of the ground and quasi-{\gamma} bands was observed. In this paper, another special point connected with the middle degenerate point is discussed, which is found to be related with the properties of 196Pt. This emergent {\gamma}-softness has also been shown to be important for understanding the prolate-oblate asymmetric shape phase transition. The low-lying spectra, B(E2) values and quadrupole moments in 196Pt are discussed showing that the new model can account for several observed features. This is the first part of the discussions on the {\gamma}-soft-like spectrum of 196Pt.

    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2308.11231 [pdf]
    CPC(2024)·13 citations
  3. 03

    [Submitted on 22 Aug 2023]

    Constructing Inverse Scattering Potentials for {\alpha}-{\alpha} System using Reference Potential Approach

    O. S. K. S. Sastri · Arushi Sharma · Ayushi Awasthi

    Background: An accurate way to incorporate long range Coulomb interaction alongside short-range nuclear interaction has been a challenge for theoretical physicists. Purpose: In this paper, we propose a methodology based on the reference potential approach for constructing inverse potentials of alpha-alpha scattering. Methods: Two smoothly joined Morse potentials, regular for short-range nuclear interaction and inverted for long range Coulomb, are used in tandem as a reference potential in the phase function method to obtain the scattering phase shifts for the S, D and G states of alpha-alpha scattering. The model parameters are optimized by choosing to minimize the mean absolute percentage error between the obtained and experimental scattering phase shift values. Results: The constructed inverse potentials for S, D and G states have resulted in mean absolute percentage errors of 0.8, 0.5, and 0.4 respectively. The obtained resonances for D and G states closely match the experimental ones. Conclusion: The reference potential approach using a combination of smoothly joined Morse functions is successful in accurately accounting for the Coulomb interaction between charged particles in nuclear scattering studies.

    Comments:
    10 pages, 4 figures, 2 Tables
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2308.11266 [pdf]
    PRC(2024)·14 citations
  4. 04

    [Submitted on 22 Aug 2023]

    Stellar weak-interaction rates for -process waiting-point nuclei from projected shell model

    Zi-Rui Chen · Long-Jun Wang

    We propose a projected shell model (PSM) for description of stellar weak-interaction rates between even-even and odd-odd nuclei with extended configuration space where up to six-quasiparticle (qp) configurations are included, and the stellar weak-interaction rates for eight -process waiting-point (WP) nuclei, Ge, Se, Kr, Sr, Zr, Mo, Ru and Pd, are calculated and analyzed for the first time within the model. Higher-order qp configurations are found to affect the underlying Gamow-Teller strength distributions and the corresponding stellar weak-interaction rates. Under -process environments with high temperatures and densities, on one hand, thermal population of excited states of parent nuclei tends to decrease the stellar decay rates. On the other hand, the possibility of electron capture (EC) tends to provide increasing contribution to the rates with temperature and density. The effective half-lives of WP nuclei under the -process peak condition are predicted to be reduced as compared with the terrestrial case, especially for Ge and Se.

    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2308.11297 [pdf]
    PLB(2024)·15 citations
  5. 05

    [Submitted on 22 Aug 2023]

    Nuclear spectrum from projected shell model (I): allowed one-to-one transition

    Fan Gao🇨🇳 · Zi-Rui Chen🇨🇳 · Long-Jun Wang🇨🇳

    Nuclear spectrum and the corresponding (anti-)neutrino spectrum play important roles in many aspects of nuclear astrophysics, particle physics, nuclear industry and nuclear data. In this work we propose a projected shell model (PSM) to calculate the level energies as well as the reduced one-body transition density (ROBTD) by the Pfaffian algorithm for nuclear decays. The calculated level energies and ROBTD are inputed to the Beta Spectrum Generator (BSG) code to study the high precision spectrum of allowed one-to-one transitions. When experimental level energies are adopted, the calculated spectrum by ROBTD of the PSM deviates from the one by the extreme simple particle evaluation of the BSG by up to , reflecting the importance of nuclear many-body correlations. When calculated level energies are adopted, the calculated spectrum shows sensitive dependence on the reliability of calculated level energies. The developed method for ROBTD by the PSM will also be useful for study of the first-forbidden transitions, the isovector spin monopole resonance etc. in a straightforward way.

    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2308.11299 [pdf]
    PRC(2023)·6 citations
  6. 06

    [Submitted on 22 Aug 2023]

    Momentum dependent measures of correlations between mean transverse momentum and harmonic flow in heavy ion collisions

    Rupam Samanta🇵🇱 · Piotr Bozek🇵🇱

    The correlation between the mean transverse momentum and the harmonic flow coefficients is an observable which is of great interest; it is sensitive to shape fluctuations in the initial state of a relativistic nuclear collision. The measurement of that correlation coefficient in central collisions allows one to infer about the intrinsic deformation of the colliding nuclei. We propose to study the momentum dependent covariance and correlation coefficient between the mean transverse momentum and the harmonic flow in a given transverse momentum bin. Two possible constructions of such observables are provided and predictions are obtained from a viscous hydrodynamic model. We find that such momentum dependent correlation coefficients between the mean transverse momentum and the harmonic flow show a strong and nontrivial momentum dependence. We also explore the effects of granularity (nucleon width) in the initial state, the nuclear deformation, and the shear viscosity on this momentum dependent correlation coefficient. The shape of the momentum dependence of the correlation coefficient for the triangular flow is found to be sensitive to the size of small scale fluctuations in the initial state. On the other hand, the shape of the momentum dependence of the covariance between the mean transverse momentum and the harmonic flow coefficients is found to be sensitive to the value of the shear viscosity and to the granularity of the initial state.

    Subjects:
    Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
    arXiv:
    2308.11565 [pdf]
    PRC(2024)·5 citations

Affiliations

first authorsco-authorsvia INSPIRE