Original scientific paper
A novel nuclear model for double beta decay
Franjo Krmpotić
; Instituto de Física, Universidade de Sao Paulo, 05315-970 Sao Paulo-SP, Brazil, Instituto de Física La Plata, CONICET, 1900 La Plata, Argentina, and Facultad de Ciencias Astronómicas y Geofísicas, Universidad Nacional de La Plata, 1900 La Plata, Argentina
Abstract
The possibility of applying the quasiparticle Tamm-Dancoff approximation (QTDA) to describe the nuclear double beta decay is explored. Several serious inconveniences found in the quasiparticle random phase approximation (QRPA), such as: i) the extreme sensitivity of the 2νββ decay amplitudes M2ν on the residual interaction in the particle-particle channel, ii) the ambiguity in treating the intermediate states and iii) the need for performing a second charge-conserving QRPA to describe the ββ-decays to the excited final states, are not present in the QTDA. Also, the QTDA allows for explicit evaluation of energy distributions of the double-charge-exchange transition strengths and of their sum rules, and can be straightforwardly applied to single- and double-closed shell nuclei. As an example, the 48Ca−→48Ti decay is discussed within the 1fp-shell in the particle-hole limit of the QTDA. The general [(1, 1)-Pad´e-approximant-like] behavior of the 2νββ-decay amplitude in the plain QRPA as well as within its different variations is briefly reviewed.
Keywords
2νββ-decay; quasiparticle Tamm-Dancoff approximation; single- and doubleclosed shell nuclei
Hrčak ID:
304093
URI
Publication date:
1.6.2005.
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