Sensitivity to alpha-variation in ultracold atomic-scattering experiments

TL;DR

This paper numerically investigates how ultracold atomic scattering lengths, especially in cesium and mercury, are sensitive to variations in the fine structure constant alpha, revealing potential for high sensitivity near Feshbach resonances.

Contribution

It extends previous methods to estimate the sensitivity of scattering lengths to alpha variation, demonstrating comparable sensitivity to beta and potential large enhancements near resonances.

Findings

Sensitivity to alpha variation can be as significant as to beta.

Near narrow Feshbach resonances, sensitivity can be enhanced by over nine orders of magnitude.

Heavy atomic systems show notable sensitivity to fundamental constant variations.

Abstract

We present numerical calculations for cesium and mercury to estimate the sensitivity of the scattering length to the variation of the fine structure constant alpha. The method used follows ideas Chin and Flambaum [Phys. Rev. Lett. 96, 230801 (2006)], where the sensitivity to the variation of the electron to proton mass ratio, beta, was considered. We demonstrate that for heavy systems, the sensitivity to variation of alpha is of the same order of magnitude as to variation of beta. Near narrow Feshbach resonances the enhancement of the sensitivity may exceed nine orders of magnitude.