Resummation of Jet Mass at Hadron Colliders

TL;DR

This paper develops a systematic method for resumming large logarithms in jet mass distributions at hadron colliders, improving theoretical predictions for jet observables by employing effective field theory and threshold expansion.

Contribution

It introduces a novel threshold expansion approach combined with effective field theory to resum jet mass logarithms at NLL and NNLL levels, including non-global effects.

Findings

Achieved resummation of jet mass logarithms at NLL and NNLL levels.

Provided a factorization formula separating global and non-global contributions.

Demonstrated the effectiveness of the method in a collider physics context.

Abstract

A method is developed for calculating the jet mass distribution at hadron colliders using an expansion about the kinematic threshold. In particular, we consider the mass distribution of jets of size R produced in association with a hard photon at the Large Hadron Collider. Expanding around the kinematic threshold, where all the energy goes into the jet and the photon, provides a clean factorization formula and allows for the resummation of logarithms associated with soft and collinear divergences. All of the large logarithms of jet mass are resummed at next-to-leading logarithmic level (NLL), and all the global logarithms at next-to-next-to-leading logarithmic level (NNLL). A key step in the derivation is the factorization of the soft function into pieces associated with single scales and a remainder which contains non-global structure. This step, which is standard in traditional resummation, is implemented in effective field theory which is then used to resum the large logarithms using the renormalization group in a systematically improvable manner.