A NOVEL NUCLEAR MODEL FOR DOUBLE BETA DECAY

[摘要] The possibility of applying the quasiparticle Tamm-Dancoff approximation (QTDA) todescribe the nuclear double beta decay is explored. Several serious inconveniences foundin the quasiparticle random phase approximation (QRPA), such as: i) the extremesensitivity of the 2nbb decay amplitudes M_2n on the residual interaction in the particle-particle channel,ii) the ambiguity in treating the intermediate states and iii) the need for performing asecond charge-conserving QRPA to describe the bb-decays to theexcited final states, are not present in the QTDA. Also, the QTDA allows for explicitevaluation of energy distributions of the double-charge-exchange transition strengths andof their sum rules, and can be straightforwardly applied to single- and double-closedshell nuclei. As an example, the ⁴⁸Ca

[学科分类] 物理（综合）

[关键词] 2nbb-decay;quasiparticle Tamm-Dancoffapproximation;single- and double-closed shell nuclei