邀请人 (Invited by): 尧江明

时间 (Time): 星期二，2023/8/22-21:00-22:00

地点 (Location):  zoom 会议

摘要 (Abstract): 

Double beta decays (ββ) are relevant to modern physics because their neutrinoless mode (0νββ) represents a possible signal of physics outside the Standard Model and also due to its importance for the study of neutrino masses. The two-neutrino mode (2νββ) is essential for testing models before extending them to 0νββ decays as well as being of physical interest in its own right. The contribution of nuclear physics to the half-lives of nuclides that undergo ββ decay is contained in the nuclear matrix element (NME). We calculate the NMEs 2νββ decay of 10 nuclides with 48≤ A≤ 150, and the 0νββ decayof 8 nuclides with 76≤ A≤ 128 in a framework based on a relativistic energy density functional. The relativistic Hartree-BCS (RHBCS) and Hartree-Bogoliubov (RHB)models were used to describe the ground state of nuclei and the proton-neutron relativistic random phase approximation (PN-RQRPA) to describe the relevant chargeexchange transitions which contribute to ββ decay. The meson exchange interaction DDME2 and the point-coupling interactions DD-PC1 and DD-PCX were used. Pairing correlations are included in both isospin channels using a separable pairing interaction. The optimal values of the isoscalar coupling strength parameter in the residual interaction were constrained from the half-lives of single β decays. In addition, calculations for 0νββ decay include the full relativistic transition operator derived without nonrelativistic reductions for the first time in a calculation based on the quasiparticle random-phase approximation.

主讲人简介 (Speaker's CV): 

Nato Popara 于 1989 年出生于克罗地亚的斯普利特。在完成物理学研究项目后， 2013 年，在克罗地亚萨格勒布大学科学院取得硕士学位。 2022 年，在萨格勒布大学获得物理学博士学位。自 2016 年以来，他一直在萨格勒布大学物理系工作。他的研究兴趣是核结构和核反应，特别是相对论平均场模型，基于随机相位近似的相对论模型，以及它们在描述弱核过程中的应用。他目前发表了 3 篇论文，他在萨格勒布大学参与普通物理课程的教学活动。