Properties of high spin states in 53Cr and 53Mn.

Abstract

High spin states of {sup 53}Cr and {sup 53}Mn have been studied by means of the reactions {sup 51}V({sup 4}He,{ital pn}{gamma}){sup 53}Cr and {sup 51}V({sup 4}He,2{ital n}{gamma}){sup 53}Mn, respectively, at {ital E}=30 MeV. In-beam {gamma}-ray singles, multiparameter coincidence, angular distribution, and Doppler-shift attenuation measurements have been performed, yielding significant new information. These include the mean lifetimes 0.15{sub {minus}0.06}{sup +0.05} ps for the 5002.4 keV (17/2{sup {minus}}) state in {sup 53}Cr; 0.23{sub {minus}0.07}{sup +0.08}, 0.17{plus minus}0.08, and 0.25{sub {minus}0.06}{sup +0.08} ps for the 4383.2 (17/2{sup {minus}}), 5613.3 (19/2{sup {minus}}), and 7961.2 (25/2{sup {minus}}) keV states, respectively, in {sup 53}Mn; multipole mixing ratios 0.11{sub {minus}0.11}{sup +0.09} for the 17/2{sup {minus}}{r arrow}15/2{sup {minus}} transition in {sup 53}Cr; {minus}0.16{sub {minus}0.08}{sup +0.03}, {minus}0.05{sub {minus}0.11}{sup +0.10}, and {minus}0.05{sub {minus}0.11}{sup +0.12} for the 19/2{sup {minus}}{r arrow}17/2{sup {minus}}, 23/2{sup {minus}}{r arrow}21/2{sup {minus}}, and 25/2{sup {minus}}{r arrow}23/2{sup {minus}} transitions, respectively, in {sup 53}Mn. The present results lend support to the existence of a {ital K}=7/2 band in {sup 53}Cr. A comparison of the experimental data with the available theoretical calculations in {sup 53}Mn shows that yrast states with {ital J}{ge}17/2 are almost pure 1p4h states.