Studies of ⁴⁴Ti and ⁴⁸Cr nuclei within variational mean field theory

We have studied the nuclear structure properties of high angular momentum states in N = Z, ⁴⁴Ti, and ⁴⁸Cr nuclei by using Hartree–Fock–Bogoliubov (HFB) method with variation after angular momentum projection (VAP-HFB) technique. Effect of Kuo–Brown "KB" and its modified effective interactions has been studied using four sets of single-particle energies (SPEs) on rotational bands of these nuclei. It is seen that the HFB theory with projected wave functions by employing the VAP method describes well the overall trends of the experimental yrast level spectrum and the transition probabilities in these nuclei. The backbending of the ⁴⁸Cr nucleus has been well reproduced by the present VAP-HFB calculations with the original "KB" effective interaction at J = 12ℏ. The modified effective interaction also gives backbending for ⁴⁸Cr but at J = 10ℏ. The shape change associated with backbending effect in ⁴⁸Cr is due to the large decrease in B(E2↓) values beyond J = 12ℏ state. (author)