IFLP   13074
INSTITUTO DE FISICA LA PLATA
$2\nu$ Double Beta Decay within the Relativistic QRPA
We perform a self-consistent relativistic QRPA (RQRPA) calculation for the$2\nu\b\b$-decays, which are  basedon  relativistic BCS (RBCS) mean field theory results forodd-odd intermediate nuclei $^{48}$Sc, $^{76}$As, $^{82}$Br, $^{100}$Tc, $^{128}$I, and $^{130}$I.The RBCS equations that resemble  the non-relativistic ones are  build up froma Dirac-Gorkov variational functional. We use the parameter set $NL1$ for the $\sigma$, $\omega$ and $\rho$ mesons.The RQRPA equations  aresolved for the residual $\pi+\rho$ interaction by employing for the later mesonthe same parameters used in the RBCS, and experimental values for the pion and nucleon.The RQRPA  results  for the ${2\nu}\b\b$ matrix elementsare similar to those obtained within the QRPA and the shell model.