Drag force in a D-instanton background

TL;DR

This paper investigates how D-instanton density affects the drag force and diffusion coefficient of a heavy quark in a high-temperature Yang-Mills plasma, revealing increased drag and decreased diffusion with D-instantons.

Contribution

It provides new insights into the impact of D-instanton density on quark dynamics in a deconfined phase, highlighting effects opposite to velocity and temperature influences.

Findings

D-instanton density increases drag force

D-instanton density decreases diffusion coefficient

D-instanton density reduces medium viscosity

Abstract

We study the drag force and diffusion coefficient with respect to a moving heavy quark in a D-instanton background, which corresponds to the Yang-Mills theory in the deconfining, high-temperature phase. It is shown that the presence of the D-instanton density tends to increase the drag force and decrease the diffusion coefficient, reverse to the effects of the velocity and the temperature. Moreover, the inclusion of the D-instanton density makes the medium less viscous.