Nuclear structure studies relevant to 136Xe ββ decay

Nuclear matrix elements of ββ decay from β-decay data

The evaluation of the nuclear matrix elements (NME) of the twoneutrino double beta (2νββ) decay and neutrinoless double beta (0νββ) decay using the proton-neutron quasiparticle random-phase approximation (pnQRPA) is addressed. In particular, the extraction of a proper value of the proton-neutron particle-particle interaction parameter, gpp, of this theory is analyzed in detail. Evidence is show...

Disassembling the nuclear matrix elements of the neutrinoless ββ decay

In this article we analyze the nuclear matrix elements (NME) of the neutrinoless double beta decays (0νββ) of the nuclei 48Ca, 76Ge, 82Se, 124Sn, 128Te, 130Te and 136Xe in the framework of the interacting shell model (ISM). We study the relative value of the different contributions to the NME’s, such as higher order terms in the nuclear current, finite nuclear size effects and short range corre...

Limits from Neutrinoless Ββ Decay

Limits on an effective Majorana neutrino mass and a lepton-number violating current admixture can be obtained from lifetime limits on 0νββ nuclear decay. The derived quantities are model-dependent, so the half-life measurements are given first. Where possible we list the references for the matrix elements used in the subsequent analysis. Since rates for the more conventional 2νββ decay serve to...

Shell-model analysis of the 136Xe double beta decay nuclear matrix elements.

Neutrinoless double beta decay, if observed, could distinguish whether the neutrino is a Dirac or a Majorana particle, and it could be used to determine the absolute scale of the neutrino masses. 136Xe is one of the most promising candidates for observing this rare event. However, until recently there were no positive results for the allowed and less rare two-neutrino double beta decay mode. Th...

Neutrino Masses , Mixing and ( Ββ ) 0 Ν − Decay