Multipolar correlations and deformation effect on nuclear transition matrix elements of double-β decay

¹  Department of Physics and Meteorology, IIT Kharagpur - Kharagpur-721302, India
²  Department of Physics, University of Lucknow - Lucknow-226007, India
³  Department of Physics, Bundelkhand University - Jhansi-284128, India
⁴  Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México A.P. 70-543, México 04510 D.F., México

Received: 28 January 2009
Accepted: 1 April 2009

Abstract

The two-neutrino and neutrinoless double-beta decay of Zr, Mo, ¹⁰⁴Ru, ¹¹⁰Pd, Te and ¹⁵⁰Nd isotopes for the 0⁺ 0⁺ transition is studied within the PHFB framework along with an effective two-body interaction consisting of pairing, quadrupole-quadrupole and hexadecapole-hexadecapole correlations. It is found that the effect of hexadecapolar correlations can be assimilated substantially as a renormalisation of the quadrupole-quadrupole interaction. The effect of deformation on nuclear transition matrix elements is investigated by varying the strength of quadrupolar correlations in the parent and daughter nuclei independently. The variation of the nuclear transition matrix elements as a function of the difference in deformation parameters of parent and daughter nuclei reveals that, in general, the former tend to be maximum for equal deformation and they decrease as the difference in deformation parameters increases, exhibiting a very similar trend for the and transition matrix elements.