Constraints on new physics from an improved calculation of parity violation in $^{133}$Cs

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We report the result of our calculation of the nuclear spin-independent parity violating electric dipole transition amplitude ($E1_{PV}$) for the $6s ~ ^2S_{1/2} - 7s ~ ^2S_{1/2}$ transition in $^{133}$Cs to an accuracy of 0.3\% using a variant of the perturbed relativistic coupled-cluster theory.

• In the present work, we treat the contributions of both the low-lying and high-lying excited states to the above mentioned amplitude on the same footing, thereby overcoming the limitations of previous high accuracy relativistic coupled cluster calculations.
• We obtain an accurate value for the vector polarizability ($\beta$) for the above transition and by combining it with the results from our present calculation of $E1_{PV}$ and the latest measurement of $Im(E1_{PV}/\beta)$, we extract the nuclear weak charge ($Q_W$); and analyze its deviation from its value in the Standard Model (SM) in order to constrain certain scenarios of new physics beyond the SM.