Evidence of antimagnetic rotational motion in Pd 103

Abstract

Lifetime measurements have been carried out for the levels of the negative parity yrast sequence in Pd103 nucleus using the Doppler shift attenuation method. The levels were populated via Zr94(C13, 4nγ)Pd103 fusion-evaporation reaction at a beam energy of 55 MeV. De-exciting γ rays were detected by utilizing the Indian National Gamma Array. The extracted transition probabilities and other auxiliary observations indicate that the sequence may be resulting from the antimagnetic rotational (AMR) motion of valence nucleons. The key characteristic feature of the AMR motion is the steady decrease of the B(E2) transition probability with spin, which is seen in the present measured transitions for Pd103. The experimental results are compared with the theoretical predictions of tilted axis cranked approach based on the covariant density functional theory. It is noted that the properties of the AMR band structure for Pd103 predicted in this model analysis are in good agreement with the present experimental findings. Further, semi-classical particle-rotor model has been employed to substantiate the AMR interpretation of the observed band structure in Pd103 and it is shown that results are similar to the band structures observed in the neighboring isotopes, which have also been considered as candidates for AMR motion. © 2021 American Physical Society.