Short-range correlations and neutrinoless double beta decay

In this work we report on the effects of short-range correlations upon the matrix elements of neutrinoless double beta decay (0v beta beta. We focus on the calculation of the matrix elements of the neutrino-mass mode of 0v beta beta decays of Ca-48 and Ge-76. The nuclear-structure components of the calculation, that is the participant nuclear wave functions, have been calculated in the shell-model scheme for 48Ca and in the proton-neutron quasiparticle random-phase approximation (pnQRPA) scheme for Ge-76. We compare the traditional approach of using the Jastrow correlation function with the more complete scheme of the unitary correlation operator method (UCOM). Our results indicate that the Jastrow method vastly exaggerates the effects of short-range correlations on the 0v beta beta nuclear matrix elements. (c) 2007 Elsevier B.V. All rights reserved.