Double-β decay within a consistent deformed approach

In this paper we present a timely application of the proton-neutron deformed quasiparticle random-phase approximation (pn-dQRPA), designed to describe in a consistent way the 1+ Gamow-Teller states in oddodd deformed nuclei. For this purpose we apply a projection before variation procedure by using a singleparticle basis with projected angular momentum, provided by the diagonalization of a spherical mean field plus quadrupole-quadrupole interaction. The residual Hamiltonian contains pairing plus proton-neutron dipole terms in particle-hole and particle-particle channels, with constant strengths. As an example we describe the two-neutrino double-beta (2νββ) decay of 150Nd to the ground state…