Strongly Coupled Soft Functions

by Dr Zhiquan Sun (University of California, Berkeley)

Friday 2 Oct 2026, 12:30 → 14:30 America/Los_Angeles

48/2-224 - Madrone (SLAC)

The renormalization of operators built out of Wilson lines that meet at an angle (cusp) involve what is known as the cusp anomalous dimension, a universal object appearing in many processes in QCD due to the divergences from gluonic interactions. In this talk, I will discuss the vacuum expectation value of a pair of cusped Wilson lines separated in the transverse direction. This configuration can be related to a simple observable in heavy quark transverse momentum-dependent (TMD) fragmentation as well as the TMD soft function. I will compute the expectation values of cusped Wilson lines in N=4 super Yang-Mills theory at strong coupling via the AdS/CFT correspondence, an approach complementary to perturbative calculations of the cusp anomalous dimension. I will also discuss the possible generalizations of our setup and results to soft functions in other gauge theories with a holographic dual.