Self-trapping of a light particle in a dense fluid: A mesoscopic model

Publisher Website
Google Scholar
Abstract
A light particle (electron, positron, or positronium atom) thermalized in a dense fluid can, in certain instances, become localized in a region of altered fluid density. This process is known as self-trapping. In this paper we formulate a mesoscopic model for the evolution of translational degrees of freedom, which uses quantum mechanics to describe the light particle (LP) and classical mechanics for the fluid molecules. The model self-consistently takes into account the mutual influence between the LP and fluid and the large isothermal compressibility near the liquid-vapor critical point. The dynamical representation of this model leads to a set of hydrodynamic equations which couples the LP wave function to the local fluid density. The equilibrium representation takes the form of a Landau-Ginzberg functional in which the wave function plays the role of order parameter. Optimization of the probability density in state space generates a mean-field theory in which the wave function is coupled to the local fluid density via a local equilibrium condition.