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Nuclear Theory·nucl-th

Monday·August 30, 2021

12 papers—7 primary·5 cross-listed

All12Primary7Cross-lists5
  1. 01

    [Submitted on 26 Aug 2021]

    Dynamical model of meson photoproduction on the nucleon and

    Sang-Ho Kim🇰🇷 · T.-S. H. Lee🇺🇸 · Seung-il Nam🇰🇷 · Yongseok Oh🇰🇷

    We investigate meson photoproduction on the nucleon and the \nuclide[4]{He} targets within a dynamical model approach based on a Hamiltonian which describes the production mechanisms by the Pomeron-exchange, meson-exchanges, radiations, and nucleon resonance excitations mechanisms. The final interactions are included being described by the gluon-exchange, direct couplings, and the box-diagrams arising from the couplings with , , , and channels. The parameters of the Hamiltonian are determined by the experimental data of from the CLAS Collaboration. The resulting Hamiltonian is then used to predict the coherent -meson production on the \nuclide[4]{He} targets by using the distorted-wave impulse approximation. For the proton target, the final rescattering effects, as required by the unitarity condition, are found to be very weak, which supports the earlier calculations in the literature. For the \nuclide[4]{He} targets, the predicted differential cross sections are in good agreement with the data obtained by the LEPS Collaboration. The role of each mechanism in this reaction is discussed and predictions for a wide range of scattering angles are presented, which can be tested in future experiments.

    Comments:
    16 pages, REVTeX
    Subjects:
    Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
    arXiv:
    2108.12039 [pdf]
    PRC(2021)·19 citations
  2. 02

    [Submitted on 27 Aug 2021]

    Nucleon momentum distribution of from the axially deformed relativistic mean-field model with nucleon--nucleon correlations

    Xuezhi Wang · Qinglin Niu · Jinjuan Zhang · Mengjiao Lyu · Jian Liu · Chang Xu · Zhongzhou Ren

    Nucleon momentum distribution (NMD), particularly its high-momentum components, is essential for understanding the nucleon--nucleon () correlations in nuclei. Herein, we develop the studies of NMD of from the axially deformed relativistic mean-field (RMF) model. Moreover, we introduce the effects of correlation into the RMF model from phenomenological models based on deuteron and nuclear matter. For the region , the effects of deformation on the NMD of the RMF model are investigated using the total and single-particle NMDs. For the region , the high-momentum components of the RMF model are modified by the effects of correlation, which agree with the experimental data. Comparing the NMD of relativistic and non-relativistic mean-field models, the relativistic effects on nuclear structures in momentum space are analyzed. Finally, by analogizing the tensor correlations in deuteron and Jastrow-type correlations in nuclear matter, the behaviors and contributions of correlations in are further analyzed, which helps clarify the effects of the tensor force on the NMD of heavy nuclei.

    Comments:
    12 pages, 10 figures, This article has been published in SCIENCE CHINA Physics, Mechanics & Astronomy(SCPMA), and the original publication is available at www.scichina.com and www.springerlink.com
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2108.12087 [pdf]
    SCPMA(2021)·14 citations
  3. 03

    [Submitted on 27 Aug 2021]

    Relativistic nucleon-nucleon potentials in a spin-dependent three-dimensional approach

    M. R. Hadizadeh · M. Radin · F. Nazari

    The matrix elements of relativistic nucleon-nucleon potentials are calculated directly from the nonrelativistic potentials as a function of relative momentum vectors, without using a partial wave decomposition. To this aim, the quadratic operator relation between the relativistic and nonrelativistic potentials is formulated in momentum-helicity basis states. It leads to a single integral equation for the two-nucleon spin-singlet state and four coupled integral equations for two-nucleon spin-triplet states, which are solved by an iterative method. Our numerical analysis indicates that the relativistic potential obtained using CD-Bonn potential reproduces the deuteron binding energy and neutron-proton elastic scattering differential and total cross-sections with high accuracy.

    Subjects:
    Nuclear Theory (nucl-th); Computational Physics (physics.comp-ph)
    arXiv:
    2108.12101 [pdf]
    Sci.Rep.(2021)·5 citations
  4. 04

    [Submitted on 27 Aug 2021]

    Super- and hyper-deformation in Zn, Zn, and Ge at high spins

    Kenichi Yoshida

    Background: The observation of the superdeformed (SD) bands in Zn indicates that the particle number 30 is a magic particle number, where two and four neutron single-particles are considered to be promoted to the intruder shell. However, the SD-yrast band in Zn is assigned negative parity. Purpose: I investigate various SD configurations in the rapidly rotating Zn and Ge, and attempt elucidating the different roles of the energy gaps at particle numbers 30 and 32. Method: I employ a nuclear energy-density functional (EDF) method: the configuration-constrained cranked Skyrme-Kohn-Sham approach is used to describe the rotational bands near the yrast line. Results: The negative-parity SD bands appear higher in energy than the positive-parity SD-yrast band in Zn by about 4 MeV, which is indicative of the SD doubly-magic nucleus. However, the energy gap in Ge is smaller MeV, though the quadrupole deformation of the SD states in Ge is greater than that of Zn. The present calculation predicts the occurrence of the hyperdeformed state in Zn and Ge at a high rotational frequency MeV due to the occupation of the shell. Conclusions: An SD-shell gap at particle number 30 and 32 appears at different deformations and the energy gap at particle number 32 is low, which make the SD structures of Zn unique, where the negative-parity SD states appear lower in energy than the positive-parity one.

    Comments:
    12 pages, 11 figures; accepted version
    Subjects:
    Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
    arXiv:
    2108.12130 [pdf]
    PRC(2022)·4 citations
  5. 05

    [Submitted on 27 Aug 2021]

    Structural and decay properties of nuclei appearing in the -decay chains of 120 within the relativistic mean-field formalism

    N. Biswal · Nishu Jain · Raj Kumar · A. S. Pradeep · M. Bhuyan

    An extensive study of -decay half-lives for various decay chains of isotopes of = 120 is performed within the axially deformed relativistic mean-field (RMF) formalism by employing the NL3, NL3, and DD-ME2 parameter set. The structural properties of the nuclei appearing in the decay chains are explored. The binding energy, quadrupole deformation parameter, root-mean-square charge radius, and pairing energy are calculated for the even-even isotopes of = 100 120, which are produced in five different -decay chains, namely, 120 No, 120 No, 120 No, 120 No, and 120 No. A superdeformed prolate ground state is observed for the heavier nuclei, and gradually the deformation decreases towards the lighter nuclei in the considered decay chains. The RMF results are compared with various theoretical predictions and experimental data. The -decay energies are calculated for each decay chain. To determine the relative numerical dependency of the half-life for a specific -decay energy, the decay half-lives are calculated using four different formulas, namely, Viola-Seaborg, Alex-Brown, Parkhomenko-Sobiczewski, and Royer for the above said five -decay chain. We notice a firm dependency of the half-life on the -decay formula in terms of -values for all decay chains. Further, the present study also strengthens the prediction for the island of stability in terms of magic number at the superheavy valley in the laboratories.

    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2108.12148 [pdf]
    Mod.Phys.Lett.A(2021)·4 citations
  6. 06

    [Submitted on 27 Aug 2021]

    Fusion cross section of the superheavy = 120 nuclei within the relativistic mean-field formalism

    Shilpa Rana · Raj Kumar · M. Bhuyan

    Present theoretical investigations aim to explore the fusion characteristics of various isotopes of Z=120 within the relativistic mean-field (RMF) formalism. We predict the most suitable projectile-target combination for the synthesis of element Z=120. The microscopic nucleon-nucleon R3Y interaction and the RMF density distributions for targets and projectiles are used to calculate the nuclear interaction potential using the double folding approach. 17 different projectile-target combinations that allow a high / ratio are considered in the present analysis to calculate the capture and/or fusion cross-section of various isotopes of Z=120 within the summed Wong formula. Further, the equivalent surface diffusion parameter is estimated to correlate the surface properties interacting nuclei with the fusion cross-section. The four Ti-based reactions with the heaviest available target Cf, namely, Ti+Cf, Ti+Cf, Ti+Cf, and Ti+Cf, and also Cr+Cm are found to have the most suitable target-projectile combinations for the synthesis of various isotopes Z=120. We also notice that Ca beams merely provide the required number of protons to synthesize the element with Z=120. We established a correlation among the surface properties of interacting nuclei with the fusion characteristics in terms of the equivalent surface diffusion parameter.

    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2108.12162 [pdf]
    Physical Review C (2021)
  7. 07

    [Submitted on 27 Aug 2021]

    Fusion dynamics of C+C reaction: An astrophysical interest within the relativistic mean-field approach

    Shilpa Rana🇮🇳 · Raj Kumar🇮🇳 · M. Bhuyan🇲🇾

    The C+C fusion reaction plays a significant role in the later phases of stellar evolution. For a better understanding of the evolution involved, one must understand the corresponding fusion-fission dynamics and reaction characteristics. In the present analysis, we have studied the fusion cross-section along with the S-factor for this reaction using the well-known M3Y and recently developed R3Y nucleon-nucleon (NN) potential along with the relativistic mean-field densities in double folding approach. The density distributions and the microscopic R3Y NN potential are calculated using the NL3 parameter set. The - summed Wong model is employed to investigate the fusion cross-section, with -values from the sharp cut-off model. The calculated results are also then compared with the experimental data. It is found that the R3Y interaction gives a reasonable agreement with the data.

    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2108.12191 [pdf]
    Astron.Nachr.(2021)·4 citations

Affiliations

first authorsco-authorsvia INSPIRE