High spin γ -ray spectroscopy in Ca41

Abstract

High spin states in $^{41}\mathrm{Ca}$ have been investigated by using $\ensuremath{\gamma}$-ray spectroscopic techniques following the $^{27}\mathrm{Al}(^{16}\mathrm{O},pn)^{41}\mathrm{Ca}$ fusion-evaporation reaction. Around twelve new transitions belonging to $^{41}\mathrm{Ca}$ have been observed and placed in the level scheme, which now has been extended up to ${E}_{x}\ensuremath{\sim}9$ MeV. The spin-parity assignments for the observed levels were arrived at following the analysis of both the coincidence intensity anisotropies and linear polarization measurements. The established 5p-4h band was extended up to ${J}^{\ensuremath{\pi}}=19/{2}^{\ensuremath{-}}$. The observations of Doppler shape and shifts facilitated the estimation of the level lifetimes by using the Doppler shift attenuation method. The lifetimes were validated with respect to previous measurements and lifetime of a few levels has been arrived at for the first time. Shell-model calculations were carried out to explain the observed level structure of the nucleus and are indicative of both single-particle and collective degrees of freedom in this $N\ensuremath{\sim}Z\ensuremath{\sim}20$ nucleus.