Partial restoration of isospin symmetry for neutrinoless double β decay in the deformed nuclear system of 150Nd

In this work, we calculate the matrix elements for the 0 nu beta beta decay of Nd-150 using the deformed quasiparticle random-phase approximation (pn-QRPA) method. We adopted the approach introduced by Rodin and Faessler [Phys. Rev. C 84, 014322 (2011)] and Simkovic et al. [87, 045501 (2013)] to restore the isospin symmetry by enforcing M-F(2 nu) = 0. We found that with this restoration, the Fermi matrix elements are reduced in the strongly deformed Nd-150 by about 15 to 20%, while the more important Gamow-Teller matrix elements remain the same. The results of an enlarged model space are also presented. This enlargement increases the total (Fermi plus Gamow-Teller) matrix elements by less than 10%.