Probing isospin symmetry in the (50Fe, 50Mn, 50Cr) isobaric triplet via electromagnetic transition rates

Lifetimes of the T = 1 isobaric analog Ip = 2+ states in 50Mn and 50Cr were measured simultaneously by employing the recoil distance Doppler-shift (RDDS) technique. The states were populated in a fusion-evaporation reaction with a ¹²C beam on a 40Ca target. An analysis of the data and the calculations from the present work, together with the available B(E2 : 2+ RT 0+) data of the isobaric analog states in 50Fe and 50Cr, were used to study isospin symmetry in the three A = 50 isobaric nuclei. Shell-model calculations reproduce the magnitudes as well as the increasing trend of the B(E2) data with increasing Z. To draw a firm conclusion on the level of isospin mixing in the triplet, a new precision measurement of the 2+ RT 0+ transition rate in 50Fe will be required.