Non-global logarithms

In perturbative quantum chromodynamics, non-global logarithms are a particular class of logarithmically enhanced higher-order corrections. These contributions are called non-global, because they arise in observables that are sensitive to emissions in only part of the phase space. Non-global logarithms are mainly driven by wide-angle soft gluons emitting softer gluons into a region of interest, and do not follow a simple exponentiation rule. Since many experimentally relevant observables are only sensitive to partons in a restricted phase space region (e.g. event shape variables and hadronic jets), non-global terms are important to consider in order to achieve theoretical predictions that are accurate beyond leading logarithms.