NNLL Resummation for Jet Broadening

TL;DR

This paper advances the precision of jet broadening calculations in particle physics by extending resummation to NNLL accuracy, enabling more accurate determinations of the strong coupling constant from experimental data.

Contribution

It computes jet and soft functions at one-loop and the collinear anomaly at two-loop, significantly improving theoretical predictions for jet broadening distributions.

Findings

Uncertainty in jet-broadening distributions is significantly reduced.

Provides a framework for precise alpha_s extraction from experimental data.

Offers a consistency check for higher-log resummations of thrust.

Abstract

The resummation for the event-shape variable jet broadening is extended to next-to-next-to-leading logarithmic accuracy by computing the relevant jet and soft functions at one-loop order and the collinear anomaly to two-loop accuracy. The anomaly coefficient is extracted from the soft function and expressed in terms of polylogarithmic as well as elliptic functions. With our results, the uncertainty on jet-broadening distributions is reduced significantly, which should allow for a precise determination of the strong coupling constant from the existing experimental data and provide a consistency check on the extraction of alpha_s from higher-log resummations of thrust.