Lightlike Wilson loops from AdS/CFT

TL;DR

This paper studies the behavior of lightlike Wilson loops in various AdS/CFT models, revealing a universal exponential linearity in their leading behavior and implications for jet-quenching parameters.

Contribution

It introduces a universal analysis of lightlike Wilson loops in diverse AdS/CFT backgrounds, highlighting their exponential linear behavior and impact on jet-quenching calculations.

Findings

Lightlike Wilson loops exhibit exponential linear behavior in these models.

The leading saddlepoint contribution results in zero jet-quenching parameter.

This behavior is universal across different AdS/CFT backgrounds.

Abstract

We investigate the lightlike limit of stationary spacelike string configurations on a large class of five-dimensional asymptotically AdS backgrounds. Specific examples include gravity duals which incorporate finite 't Hooft coupling, curvature-squared corrections, and chemical potentials. A universal feature of these AdS/CFT models is that the string solution with minimum action yields a lightlike Wilson loop whose leading behavior is exponentially linear, rather than quadratic, in the width of the loop. Unless there is a compelling reason for discarding the leading saddlepoint contribution to the Wilson loop, following the proposal of Liu et. al. [2] leads to zero jet-quenching parameter for all of these models.