The Reggeon 2 Reggeons Particle vertex in the Lipatov effective action formalism
arXiv:hep-ph/0612323 · doi:10.1140/epjc/s10052-007-0270-2
Abstract
The vertex for gluon emission during the splitting of a reggeized gluon into two is constructed in the framework of Lipatov effective action formalism. Its reduction to a pure transverse form for the diffractive amplitude gives the standard Bartels vertex plus an additional contribution corresponding to the emission from a pointlike splitting vertex. This additional contribution turns out to be given by a longitudinal integral divergent both in the ultraviolet and infrared. A certain specific recipe for this part, including the principal value prescription for the integration, allows to eliminate this unwanted contribution.
4 figures; misprints corrected; to be published in Eur.Phys.J. C