Evidence of the Antimagnetic rotation in an odd-odd nucleus: The case of 142Eu

TL;DR

This study provides conclusive experimental evidence for antimagnetic rotational bands in the odd-odd nucleus 142Eu, supported by polarization measurements, lifetime data, and theoretical modeling, marking a significant advancement in understanding nuclear rotation phenomena.

Contribution

First definitive identification of an antimagnetic rotational band in an odd-odd nucleus, combining experimental polarization, lifetime measurements, and semi-classical modeling.

Findings

Confirmed anti-magnetic rotation in 142Eu through polarization and lifetime data.

Observed decreasing B(E2) with increasing spin, characteristic of AMR.

Theoretical calculations successfully reproduced experimental trends.

Abstract

The present work reported a conclusive evidence for anti-magnetic rotational (AMR) band in an odd-odd nucleus 142Eu. Parity of the states of a quadrupole sequence in 142Eu was firmly identified from polarization measurements using the Indian National Gamma Array and lifetimes of some of the states in the same structure were measured using the Doppler shift attenuation method. The decreasing trends of the deduced quadrupole transition strength B(E2) with spin, along with increasing J(2) / B(E2) values conclusively established the origin of these states as arising from Antimagnetic rotation. The results were well reproduced by numerical calculations within the framework of a semi-classical geometric model.