New BCS and renormalized QRPA formalism with application to double beta decay
A. Bobyk - W.A. Kaminski - P. Zareba
Department of Theoretical Physics, Maria Curie-Skodowska University,
Radziszewskiego 10, PL-20-031 Lublin, Poland (e-mail: kaminski@neuron.umcs.lublin.pl)
Received: 4 January 1999 / Revised version: 29 March 1999 Communicated by P. Povh
Abstract
A new analysis of the renormalized proton-neutron quasiparticle
random phase approximation based on simultaneous recalculation of the one-body
density matrix and the pairing tensor has been used to study the double beta
decay. We demonstrated that inclusion of the quasiparticle correlations at
the BCS level reduces ground state correlations in the particle-particle
channel of the proton-neutron interaction. We also simplified the RQRPA
equations significantly obtaining a low-dimensioned set of linear equations for
the quasiparticle densities. The formalism was applied to the double beta decay
of 76Ge.
PACS
21.60Jz Hartree±Fock and random-phase approximations -
23.40.Bw Weak-interaction and lepton (including neutrino) aspects -
23.40.Hc Relation with nuclear matrix elements and nuclear structure
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