2020/03/09 by Sarkar, Shahariar, Kumar, Pawan, Jha, Kanhaiya +1
#FOS: Physical sciences #Nuclear Theory (nucl-th)
paper · doi:10.48550/arxiv.2003.05060
In the present work, we examine the role of central (C), spin-orbit (SO) and tensor (T) components of two-nucleon interaction in the nuclear matrix elements (NMEs) of the two-neutrino double beta decay (2νββ) and the light neutrino-exchange mechanism of neutrinoless double beta decay (0νββ) of 48Ca in closure approximation and nonclosure approach. The NMEs are calculated in the nuclear shell-model framework using two-nucleon effective interaction GXPF1A used for pf shell. The decomposition of the shell model two-nucleon interaction into its individual components is performed using the spin-tensor decomposition (STD). The NMEs for 2νββ are calculated in running nonclosure method. The NMEs for 0νββ are calculated with four different methods, namely, closure, running closure, running nonclosure, and mixed method. Results show that the magnitude of NMEs for 2νββ decreases about 7% with the C+SO component of the interaction as compared to the C component. The magnitude of NMEs is further decreased about 9% by adding T component to the C+SO component. The NMEs of 0νββ calculated in running nonclosure method are enhanced by about 8-10%, 8-10%, and 9-12%, respectively, as compared to corresponding NMEs calculated in running closure method with C, C+SO components and total (C+SO+T) GXPF1A interaction for different SRC parametrization. For both 2νββ and 0νββ, the NMEs calculated with C+SO component is in opposite phase with the NMEs calculated with C component and the total GXPF1A interaction.