Isospin and F-spin structure in low-lying levels of 48,50Cr isotopes

Abstract

The low-energy level structure and electromagnetic transitions of ${}^{48,50}$Cr nuclei have been studied by using interacting boson model with isospin (IBM-3). A sequence of isospin excitation bands with isospin $(T=T_z$, $T_z+1$ and $T_z+2)$ has been assigned, and compared with available data. According to this study, the $2_3^{+}$ and $2_2^{+}$ states are the lowest mixed symmetry states in ${}^{48,50}$Cr respectively. In particular, the present calculations suggest that a combination of isospin and F-spin excitation can explain the structure in these nuclei. The transition probabilities between the levels are analyzed in terms of isoscalar and isovector decomposition which reveal the detailed nature of the energy levels. The results obtained are found in good agreement with recent experimental data.

Comments: 11 pages and 8 figures