RaH as a potential candidate for electron electric-dipole-moment searches

Abstract

Diatomic polar molecules have been the focus of research in the recent past as candidates for electron electric dipole moment (eEDM), de, measurements. In the present work, we focus on RaH molecule and have calculated three of its properties (in the X2Σ+ state) the effective electric field (Eeff), the scalar-pseudoscalar (S-PS) interaction coefficient (Ws,A), and permanent electric dipole moment (PDM) that play crucial roles in probing fundamental symmetry violations. The calculations were based on the relativistic coupled-cluster singles and doubles (RCCSD) frame work. Our results for Eeff, Ws,A, and PDM are 80.31 GV/cm, 216.82 kHz, and 4.44 D respectively. In addition to possessing high magnitudes of Eeff and Ws,A, RaH also has a large PDM, which is a highly desirable criterion for eEDM experiments. The analysis of our results clearly indicates the spectacular role of electron correlation in enhancing their magnitudes ≈16% for PDM and ≈31% for Eeff and Ws,A. The ratio of Eeff to Ws,A for RaH is 89.56×1018e−1 cm−1. Based on our results and other experimental considerations, we propose RaH as a future candidate for experiments in this field.