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Nuclear Theory·nucl-th

Tuesday·June 6, 2023

11 papers—4 primary·7 cross-listed

All11Primary4Cross-lists7
  1. 01

    Shell model study of first-forbidden beta decay around Pb

    P. C. Srivastava · S. Sharma · A. Kumar · P. Choudhary

    In the present work, we report a systematic theoretical study of the values for the forbidden decay transitions in the Pb region. For this, we have considered Hg Tl, Hg Tl, Tl Pb and Tl Pb transitions. We have performed shell model calculations using KHH7B interaction in valence shell 58-114 for protons and 100-164 for neutrons by considering excitations for both protons and neutrons simultaneously for daughter nuclei. This study presents the first shell model results of -decay corresponding to the recent experimental data.

    nucl-thnucl-exJ.Phys.Conf.Ser.(2023)·4 citations
  2. 02

    TRABZO: a novel combined model for heavy-ion fusion/capture accounting for zero-point shape oscillations and dissipative effects

    Maria V. Chushnyakova

    The fusion/capture cross sections (CSs) of complex nuclei (heavy ions) are often described in the literature within two approaches: i) the coupled channels model accounting for structure of the colliding nuclei and ii) trajectory models with friction and thermal fluctuations (dissipative effects). The first approach does not account for friction whereas the second one is not able to deal with sub-barrier CSs. In the present work, we have developed an algorithm for calculating the capture CSs of collision of spherical nuclei accounting for both zero-point oscillations (ZPO) of the nuclear shapes (structure effects) and for dissipative effects; i.e., in a sense we have combined the above two approaches. The bare nucleus-nucleus potential is evaluated using the semi-microscopic double-folding model with M3Y-Paris nucleon-nucleon forces. The nucleon densities are taken from the IAEA data base. For each collision partner several deformations of quadrupole and octupole type are accounted for with the probabilities corresponding to the harmonic oscillator at the ground state. The dissipative effects enter into our combined approach within the surface friction model well known in the literature. The final fate of a trajectory is decided by means of quantum transmission coefficients. There are two fitting parameters in the model, tau and K_R. Parameter tau reflects to what extent ZPO survives when the reagents approach each other. Parameter K_R is the friction strength for the radial motion. All calculations have been performed for 16O+92Zr reaction. The calculated CSs and barrier distribution are found in good agreement with the precision experimental data at reasonable values of tau and K_R. Calculations show that the CSs are mostly sensitive to tau at low (sub-barrier) collision energies whereas the value of K_R is important at the above barrier energies.

    nucl-th0 citations
  3. 03

    Role of three-body dynamics in nucleon-deuteron correlation functions

    M. Viviani🇮🇹 · S. König🇺🇸 · A. Kievsky🇮🇹 · L. E. Marcucci🇮🇹 · B. Singh🇩🇪 · O. Vázquez Doce🇮🇹

    Correlation functions of hadrons can be accessed in high-energy collisions of atomic nuclei, revealing information about the underlying interaction. This work complements experimental efforts to study nucleon-deuteron -- with (proton) or (neutron) -- correlations with theory evaluations using different techniques. The correlation functions and are calculated based on scattering wave function, extending previous benchmarks for the scattering matrix to this new observable. We use hyperspherical harmonics and Faddeev techniques with one of the widely used nucleon-nucleon () interactions, the Argonne potential. Moreover, in the low-energy region we perform additional calculations in the framework of pionless effective field theory. The correlation function is computed in the large-energy region to make contact with a recent measurement by the ALICE Collaboration. We show that the scattering wave function has the proper dynamical input to describe an initial rise and subsequent oscillations of as a function of the energy. Effects on the observables using different and three-nucleon potentials are evaluated with the conclusion that variations of around are observed. Although these effects are small, future measurements can go beyond this accuracy allowing for new detailed studies of strong interaction in light nuclear systems. The present study supports the current efforts devoted to the measurement of correlation functions in systems dominated by the strong interactions, such as , , and .

    nucl-thhep-exPRC(2023)·32 citations
  4. 04

    Dynamic Calculations of Magnetic Field and Implications on Spin Polarization and Spin Alignment in Heavy Ion Collisions

    Hui Li🇨🇳 · Xiao-Liang Xia🇨🇳 · Xu-Guang Huang🇨🇳 · Huan Zhong Huang🇨🇳

    Magnetic field plays a crucial role in various novel phenomena in heavy-ion collisions. We solve the Maxwell equations numerically in a medium with time-dependent electric conductivity by using the Finite-Difference Time-Domain (FDTD) algorithm. We investigate the time evolution of magnetic fields in two scenarios with different electric conductivities at collision energies ranging from 7.7 to 200 GeV. Our results suggest that the magnetic field may not persist long enough to induce a significant splitting between the global spin polarizations of and at freeze-out stage. However, our results do not rule out the possibility of the magnetic field influencing the spin (anti-)alignment of vector mesons.

    nucl-thPRC(2023)·14 citations

Affiliations

first authorsco-authorsvia INSPIRE