AG视讯厅:INPAC Seminars

Nuclear Symmetry Energy in Finite Nuclei

Prof. Mitko K. Gaidarov, Bulgarian Academy of Sciences
Tue, 2017-07-11 13:30 - 14:30
Lecture Hall/INPAC (AG视讯厅粒子物理和核物理研究所)

    The nuclear symmetry energy (NSE) as a fundamental quantity in nuclear physics and astrophysics represents a measure of the energy gain in converting isospin asymmetric nuclear matter (ANM) to a symmetric system. A natural and important way to learn more about the NSE is the transition from ANM to finite nuclei.
    In my talk I’ll focus on a possible way to study important microscopic nuclear matter quantities in finite nuclei and their relation to surface properties of neutron-rich exotic nuclei. A theoretical approach to the nuclear many-body problem combining the deformed self-consistent mean-field HF+BCS method with Skyrme-type density-dependent effective interactions and the coherent density fluctuation model (CDFM) has been used to study nuclear properties of isotopic chains of even-even spherical Ni, Sn, and Pb and deformed Kr and Sm nuclei. Particularly, we study the correlation between the thickness of the neutron skin in these nuclei and the NSE. In addition, a comprehensive study of various ground-state properties of neutron-rich and neutron-deficient Mg isotopes with A=20-36 is performed. Within our theoretical scheme we probe the emergence of an "island of inversion" at neutron-rich 32Mg nucleus, that was recently proposed from the analyses of spectroscopic measurements of 32Mg low-lying energy spectrum and the charge rms radii of all magnesium isotopes in the sd shell.
    Besides the density dependence, the temperature dependence of the symmetry energy for isotopic chains of Ni, Sn, and Pb nuclei is investigated in the framework of the local density approximation. The temperature dependence of the neutron and proton root-mean-square radii and corresponding neutron skin thickness is also investigated, showing that the effect of temperature leads mainly to a substantial increase of the neutron radii and skins, especially in the more neutron-rich nuclei, a feature that may have consequences on astrophysical processes and neutron stars.
    The volume and surface components of the NSE and their ratio are calculated within the CDFM. The estimations use the results of the model for the NSE in finite nuclei based on the Brueckner and Skyrme energy-density functionals (EDFs) for nuclear matter. The obtained results could provide a possibility to test the properties of the nuclear EDFs and characteristics related to NSE, e.g., the neutron skin thickness of finite nuclei.                  

Host: Prof. Lie-Wen Chen