Sensitive behavior of -decay amplitude within QRPA and broken symmetry in nuclei
✍ Scribed by Vadim A. Rodin; Michael H. Urin; Amand Faessler
- Publisher
- Elsevier Science
- Year
- 2005
- Tongue
- English
- Weight
- 175 KB
- Volume
- 747
- Category
- Article
- ISSN
- 0375-9474
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✦ Synopsis
Making use of an identity transformation independent of a nuclear model, we represent the 2νββamplitude as a sum of two terms. One term accounts for most of the sensitivity of the original 2νββ-amplitude to g pp for realistic g pp 1 (with g pp being the ratio of the triplet and singlet p-p interaction strengths) and is determined by a specific energy-weighted sum rule. The sum rule depends only on the particle-particle residual interaction (being linear function of g pp in the QRPA) and passes through zero at the point g pp = 1 where the Wigner SU(4) symmetry is restored in the p-p sector of the Hamiltonian. The second term in the decomposition of the 2νββ-amplitude is demonstrated within the QRPA to be a much smoother function for the realistic values of g pp than the original 2νββ-amplitude. This term is mainly determined by the intensity of the spin-orbit interaction of the nuclear mean field. Thus, the analysis of the present work reveals the reasons for the sensitivity of the 2νββ-amplitude to different components of the nuclear Hamiltonian and thereby can help in constraining nuclear model uncertainties in calculations of the amplitude.