Critical opalescence in fluids: 1.5-Scattering effects and the Landau-Placzek ratio

TL;DR

This paper investigates the role of 1.5-scattering in fluids and its impact on the Landau-Placzek ratio, providing new arguments and analyzing experimental data to support its significance in critical opalescence phenomena.

Contribution

It introduces new theoretical arguments for 1.5-scattering's importance and analyzes experimental data to evaluate its magnitude and sign in critical opalescence.

Findings

Evidence supporting the existence of 1.5-scattering in fluids

Quantitative evaluation of 1.5-scattering's contribution to the Landau-Placzek ratio

Insights into the role of 1.5-scattering in critical opalescence phenomena

Abstract

We adduce new arguments for the significance of so-called 1.5- (or sesquialteral) molecular light scattering in one-component fluids. For this purpose, we analyze its effect on the Landau-Placzek ratio for the critical opalescence spectrum. The results obtained are used to reveal experimental data which can be interpreted as evidence for its existence and to evaluate both the relative magnitude and the sign of the 1.5-scattering contribution.