Time reversal violating Magnetic Quadrupole Moment in heavy deformed nuclei

TL;DR

This paper investigates how nuclear deformation enhances magnetic quadrupole moments (MQMs) in heavy nuclei and explores their effects on atomic and molecular EDMs, providing insights into CP-violation tests.

Contribution

It presents calculations of nuclear MQMs in deformed nuclei using the Nilsson model and assesses their impact on molecular energy shifts relevant for experiments.

Findings

Nuclear deformation significantly enhances MQMs in heavy nuclei.

Calculated MQMs for specific deformed nuclei relevant to experiments.

Estimated energy shifts in molecules due to nuclear MQMs.

Abstract

The existence of permanent electric dipole moments (EDMs) and magnetic quadrupole moments (MQMs) violate both time reversal invariance ($T$) and parity ($P$). Following the $CPT$ theorem they also violate combined $CP$ symmetry. Nuclear EDM are completely screened in atoms and molecules while interaction between electrons and MQM creates atomic and molecular EDM which can be measured and used to test CP-violation theories. Nuclear MQM are produced by the nucleon-nucleon $T,P$-odd interaction and by nucleon EDM. In this work we study the effect of enhancement of the nuclear MQM due to the nuclear deformation. Using the Nilsson model we calculate the nuclear MQMs for deformed nuclei of experimental interest and the resultant MQM energy shift in diatomic molecules of experimental interest $^{173}$YbF , $^{177,179}$HfF$^+$, $^{181}$TaN, $^{181}$TaO$^+$, $^{229}$ThO and $^{229}$ThF$^+$.