Numerical resummation at subleading color in the strongly ordered soft gluon limit

We present a Monte Carlo approach to soft-gluon resummation at subleading color which can be used to improve existing parton shower algorithms. At the single-emission level, soft-collinear enhancements of the splitting functions are explicitly linked to quadratic Casimir operators, while wide angle single-soft enhancements are connected to nontrivial color correlators. We focus on a numerically stable implementation of color matrix element corrections to all orders and approximate the virtual corrections by requiring unitarity at the single-emission level. We provide a proof-of-concept implementation to compute nonglobal event shapes at lepton colliders.

Automated summary

A Monte Carlo approach for soft-gluon resummation at subleading color is presented to enhance existing parton shower algorithms. The study focuses on numerically stable implementation of color matrix element corrections and approximates virtual corrections by requiring unitarity at the single-emission level. A proof-of-concept implementation to compute nonglobal event shapes at lepton colliders is provided.