Effective Coupling Constants for M1, M2 and E3 Transition in f-p Shell Nuclei

Abstract

Electromagnetic transitions for low-lying states in 67 Ge were examined by measuring gamma rays and internal conversion electrons following the nat Zn(α,n) 67 Ge reaction. The 734-keV gamma ray was found to be the single-quasi-neutron (1g 9/2 →1f 5/2 ) M2 transition. The halflife is (102±10) ns. The reduced M2 matrix element is (2.32±0.24) \((e\hbar/\text{2M}c)^{2}\) fm 2 . This gives the renormalization factor g eff (M2)/ g free (M2)=0.25±0.03. A systematic survey was made of the single-quasi-particle M2(1g 9/2 →1f 5/2 ), the single quasi-particle E3 (1g 9/2 →2p 3/2 ) and the l -forbidden M1 (1f 5/2 →2p 3/2 ) transitions in the fp-shell nuclei. The renormalization factors for these transitions were analyzed in terms of the core polarizations associated with those transition modes.