Spectroscopy of the N=Z-2 nucleus Cr46 and mirror energy differences
Garrett PE., Lenzi SM., Algin E., Appelbe D., Bauer RW., Becker JA., Bernstein LA., Cameron JA., Carpenter MP., Janssens RVF., Lister CJ., Seweryniak D., Warner DD.
Excited states in Cr46 were sought using the C12(Ar36,2n) reaction. Gamma rays were detected with the Gammasphere array, and the Z value of the reaction products was determined with an ionization chamber located at the focal plane of the Fragment Mass Analyzer. In addition to the ground-state band observed up to IÏ€=10+ (tentatively 12+), five states are proposed to belong to the 3- band. The mirror energy differences with the analog states in Ti46 present a pronounced staggering effect between the odd and even spin members that is reproduced well by shell-model calculations incorporating the different Coulomb contributions, monopole, multipole, and single-particle effects together with an isospin-nonconserving interaction that accounts for the so-called J=2 anomaly. Dramatically different E1 decay patterns for members of the 3- band between the Cr46 and Ti46 mirrors are also observed. © 2007 The American Physical Society.