QCD resummation for high-p$_T$ jet shapes at hadron colliders

TL;DR

This paper advances the theoretical understanding of high-pT QCD jet substructure at the LHC by providing state-of-the-art calculations of non-global logarithms, which are crucial for accurate jet shape predictions.

Contribution

It presents the first comprehensive fixed-order and all-orders calculations of non-global logarithms for high-pT jet shapes, addressing a long-standing gap in the literature.

Findings

Improved theoretical predictions for non-global jet shape distributions.

Enhanced understanding of perturbative QCD effects in jet substructure.

Stimulated further research in effective field theory approaches.

Abstract

Exploiting the substructure of jets observed at the LHC to better understand and interpret the experimental data has recently been a very active area of research. In this thesis we study the substructure of high-p$_T$ QCD jets, which form a background to many new physics searches. In particular, we explore in detail the perturbative distributions of a certain class of observables known as non-global jet shapes. More specifically, we identify and present state-of-the-art calculations, both at fixed-order and to all-orders in the perturbative expansion, of a set of large logarithms known as non-global logarithms. Hitherto, these logarithms have been largely mistreated, and in many cases ignored, in the literature despite being first pointed out more than a decade ago. Our work has triggered the interest of many groups, particularly Soft and Collinear Effective Theory (SCET) groups, and led to a flurry of papers on non-global logarithms and related issues.