Revisiting parity non-conservation in cesium

TL;DR

This paper refines calculations of parity non-conservation in cesium by including significant corrections from core and highly excited states, leading to results that better align with previous theories and impact constraints on new physics.

Contribution

It introduces an improved sum-over-states approach accounting for core and tail contributions, refining PNC calculations in cesium and enhancing agreement with prior results.

Findings

Corrected PNC amplitude to 0.8977(40) from 0.8906(24)

Results align closely with previous calculations, 0.8980(45)

Supports standard model consistency with cesium PNC measurements

Abstract

We apply the sum-over-states approach to calculate partial contributions to the parity non-conservation (PNC) in cesium [Porsev {\em et al}, Phys. Rev. D {\bf 82}, 036008 (2010)]. We have found significant corrections to two non-dominating terms coming from the contribution of the core and highly excited states ($n>9$, the so called {\em tail}). When these differences are taken into account the result of Porsev {\em et al}, $E_{\rm PNC} = 0.8906\,(24) \times 10^{-11}i(-Q_W/N)$ changes to $0.8977\,(40)$, coming into good agreement with our previous calculations, $0.8980\,(45)$. The interpretation of the PNC measurements in cesium still indicates reasonable agreement with the standard model ($1.5\,\sigma$), however gives new constraints on physics beyond it.