Enhanced nonperturbative effects in jet distributions

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.

Significant changes made. The first moment does not vanish--the paper has been modified to reflect this. Relations between different numbers of jets still hold