Search for anisotropic effects of hcp solid helium on optical lines of cesium impurities

TL;DR

This study investigates whether hcp solid helium induces anisotropic effects on cesium atoms' optical lines, aiming to detect potential parity-violating phenomena, but finds no significant polarization-dependent effects, indicating isotropic conditions.

Contribution

The paper experimentally examines the anisotropic effects of hcp helium on cesium optical lines, providing evidence for isotropic environment despite theoretical expectations.

Findings

No significant polarization-dependent splitting observed.

Cesium atoms experience an isotropic solid environment.

Results suggest absence of detectable anisotropic effects.

Abstract

The anisotropic effect of a hcp 4He solid matrix on cesium atoms has been proposed as a tool to reveal the parity violating anapole moment of its nucleus. It should also result in splitting the D2 optical excitation line in a way depending on the light polarization. An experimental investigation has been set up using oriented hcp helium crystals in which cesium metal grains are embedded. Atoms are created by laser sputtering from this grains. Optical absorption spectra of the D2 line have been recorded in the temperature range of 1.0 to 1.4 K at liquid/solid coexistence pressure by monitoring the fluorescence on the D2 line at 950 nm. No significant effect of the light polarization has been found, suggesting a statistically isotropic disordered solid environment for the cesium atoms.