Identity of the rotational bands in ²⁵¹Md and ²⁵⁵Lr by a particle-number-conserving method based on the cranked shell model

Abstract The observed identical π 7/2 − [514] band and near-identical π 1/2 − [521] band in 251 Md and 255 Lr are investigated using the cranked shell model (CSM) with the particle-number-conserving (PNC) pairing method. The experimental kinematic moments of inertia (MOIs) J (1) for each band are reproduced well by the PNC-CSM calculations. A remarkable identity is exhibited for the variation of the calculated MOIs J (1) versus the frequency between 251 Md and 255 Lr, which is attributed to the identical contributions of the alignment from the blocked proton orbitals π [514]7/2 ( π [521]1/2) in 251 Md and 255 Lr. The slight differences of J (1) at high frequency ℏω > 0.2 MeV for the near-identical π 1/2 − [521] band are due to the contributions of the direct term j (1) ( μ ) and the interference term j (1) ( μν ) based on the neutron orbital ν 9/2 − [734]. The B ( E 2) values are lower in 251 Md than in 255 Lr while the pairing gaps are almost the same for the π 7/2 − [514] and π 1/2 − [521] bands. The behaviors of the B ( E 2) values (pairing gaps) versus frequency are predicted to exhibit a remarkable similarity in 251 Md and 255 Lr.