Abstract:
Employing the projected-Hartree-Fock-Bogoliubov (PHFB) approach, nuclear transition
matrix elements (NTMEs) have been calculated to study the three complementary
modes of β
−β
− decay, namely two neutrino β
−β
− (2νβ−β
−) decay, neutrinoless β
−β
−
(0νβ−β
−) decay within mass mechanism and Majoron accompanied 0νβ−β
− (0νβ−β
−χ)
decay. Reliability of HFB wave functions generated with four different parametrizations of
the pairing plus multipolar type of effective two-body interaction has been ascertained
by comparing a number of nuclear observables with the available experimental data.
Specifically, the calculated NTMEs M(2ν) of 2νβ−β
− decay have been compared with
the observed data. Effects due to different parametrizations of effective two-body
interactions, form factors and short-range correlations have been studied. It has also
been observed that deformation plays a crucial role in the nuclear structure aspects of
0νβ−β
− decay. Uncertainties in NTMEs calculated with wave functions generated with
four different parametrizations of the pairing plus multipolar type of effective two-body
interaction, dipole form factor and three different parametrizations of Jastrow type of
short-range correlations within mechanisms involving light Majorana neutrinos, heavy
Majorana neutrinos, sterile neutrinos and Majorons have been statistically estimated.
