Enhanced nonperturbative effects in jet distributions

TL;DR

Nonperturbative effects in four or more jet events are completely determined in terms of two matrix elements which can be measured in two- and three-jet events.

Abstract

We consider the triple differential distribution dΓ/(dE_J)(dm_J^2)(dΩ_J) for two-jet events at center of mass energy M, smeared over the endpoint region m_J^2 << M^2, |2 E_J -M| ~ Δ, \lqcd << Δ<< M. The leading nonperturbative correction, suppressed by \lqcd/Δ, is given by the matrix element of a single operator. A similar analysis is performed for three jet events, and the generalization to any number of jets is discussed. At order \lqcd/Δ, non-perturbative effects in four or more jet events are completely determined in terms of two matrix elements which can be measured in two and three jet events.

Figures (1)

• Figure 1: Pictorial representation of the Wilson lines occurring in the shape function $S(k)$ defined in Eq. (\ref{['sdef']}).