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Nuclear Theory·nucl-th

Tuesday·May 29, 2018

17 papers—3 primary·14 cross-listed

All17Primary3Cross-lists14
  1. 01

    Test of Isospin Conservation in Thermal Neutron-induced Fission of Cm

    Swati Garg · Ashok Kumar Jain

    We have, recently, shown that the general trends of partition-wise fission fragment mass distribution in heavy ion (HI) induced compound nuclear (CN) fission of heavy nuclei can be reproduced reasonably well by using the concept of isospin conservation, hence providing a direct evidence of isospin conservation in neutron-rich systems [1, 2, 3, 4]. In this paper, we test the concept of isospin conservation to reproduce the fission fragment mass distribution emerging from thermal neutron-induced CN fission reaction, 245Cm(nth, f). As earlier, we use Kelson's conjectures [5] to assign isospin to neutron-rich fragments emitted in fission, which suggest the formation of fission fragments in Isobaric Analog states (IAS). We calculate the relative yields of neutron-rich fragments using the concept of isospin conservation and basic isospin algebra. The calculated results reproduce quite well the experimentally known partition wise mass distributions. This highlights the usefulness of isospin as an approximately good quantum number in neutron-rich nuclei. This also allows us to predict the fragment distribution of the most symmetric Cd-Cd partition and the heavier mass fragment distributions, both not measured so far.

    nucl-thPramana(2019)·6 citations
  2. 02

    Quarkonia production in a Langevin approach

    C. Greiner🇩🇪 · N. Krenz🇩🇪 · H. van Hees🇩🇪

    We aim to describe the process of dissociation and recombination of quarkonia in the quark-gluon plasma. Therefore we developed a model which allows to observe the time evolution of a system with various numbers of charm-anticharm-quark pairs at different temperatures. The motion of the heavy quarks is realized within a Langevin approach. We use a simplified version of a formalism developed by Blaizot et al. in which an Abelian plasma is considered where the heavy quarks interact over a Coulomb like potential. We have demonstrated, that the system reaches the expected thermal distribution in the equilibrium limit.

    nucl-thJ.Phys.Conf.Ser.(2018)·3 citations
  3. 03

    Correlated transitions in TKE and mass distributions of fission fragments described by 4-D Langevin equation

    M. D. Usang · F. Ivanyuk · C. Ishizuka · S. Chiba

    We have decomposed to symmetric and asymmetric modes the mass-TKE fission fragment distributions calculated by 4-dimensional Langevin approach and observed how the dominant fission mode and symmetric mode change as functions of of the fissioning system in the actinides and trans-actinide region. As a result, we found that the symmetric mode makes a sudden transition from super-long to super short fission mode around Es. The dominant fission modes on the other hand, are persistently asymmetric except for Fm, Fm and Md when the dominant fission mode suddenly becomes symmetric although it returns to the asymmetric mode around No. These correlated "twin transitions" have been known empirically by Darleane Hoffman and her group back in 1989, but for the first time we have given a clear explanation in terms of a dynamical model of nuclear fission. More specifically, since we kept the shape model parameters unchanged over the entire mass region, we conclude that the correlated twin transition emerge naturally from the dynamics in 4-D potential energy surface.

    nucl-thSci.Rep.(2019)·62 citations

Affiliations

first authorsco-authorsvia INSPIRE