Rapidity veto effects in the NLO BFKL equation

We examine the effect of suppressing the emission of gluons which are close by in rapidity in the BFKL framework. We show that, after removing the unp hysical collinear logarithms which typically arise in formally higher order s of the perturbative expansion, the effect of the rapidity veto is greatly reduced. This is an important result, since it supports the use of multi-R egge and quasi-multi-Regge kinematics which are implemented in the leading and next-to-leading order BFKL formalism. (C) 1999 Elsevier Science B.V. Al l rights reserved.