分类: 物理学 >> 核物理学 提交时间: 2017-08-22
摘要: We study the proton magic O, Ca, Ni, Zr, Sn, and Pb isotope chains from the proton drip line to the neutron drip line with the relativistic con- tinuum Hartree-Bogoliubov (RCHB) theory. Particulary, we study in detail the properties of even-even Ca isotopes due to the appearance of giant ha- los in neutron rich Ca nuclei near the neutron drip line. The RCHB theory is able to reproduce the experimental binding energies Eb and two neutron separation energies S2n very well. The predicted neutron drip line nuclei are 28O, 72Ca, 98Ni, 136Zr, 176Sn, and 266Pb, respectively. Halo and giant halo properties predicted in Ca isotopes with A > 60 are investigated in detail from the analysis of two neutron separation energies, nucleon density distri- butions, single particle energy levels, the occupation probabilities of energy levels including continuum states. The spin-orbit splitting and the diffuseness of nuclear potential in these Ca isotopes are studied also. Furthermore, we study the neighboring lighter isotopes in the drip line Ca region and find some possibility of giant halo nuclei in the Ne-Na-Mg drip line nuclei.
分类: 物理学 >> 核物理学 提交时间: 2016-09-14
摘要: Topological charge susceptibility χt for pure gauge SU(3) theory at finite temperature is studied using anisotropic lattices. The over-improved stout-link smoothing method is utilized to calculate the topological charge. Near the phase transition point we find a rapid declining behavior for χt with values decreasing from (188(1)MeV)4 to (67(3)MeV)4 as the temperature increased from zero temperature to 1.9Tc which demonstrates the existence of topological excitations far above Tc. The 4th order cumulant c4 of topological charge, as well as the ratio c4/χt are also investigated. Results of c4 show step-like behavior near Tc while the ratio at high temperature agrees with the value as predicted by the diluted instanton gas model.