Endpoint singularities in unintegrated parton distributions

We examine the singular behavior from the endpoint region x → 1 in parton distributions unintegrated in both longitudinal and transverse momenta. We identify and regularize the singularities by using the subtraction method, and compare this with the cut-off regularization method. The counterterms fo...

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Detalles Bibliográficos
Autor principal: Hautmann, F
Formato: Journal article
Lenguaje:English
Publicado: 2007
Descripción
Sumario:We examine the singular behavior from the endpoint region x → 1 in parton distributions unintegrated in both longitudinal and transverse momenta. We identify and regularize the singularities by using the subtraction method, and compare this with the cut-off regularization method. The counterterms for the distributions with subtractive regularization are given in coordinate space by compact all-order expressions in terms of eikonal-line operators. We carry out an explicit calculation at one loop for the unintegrated quark distribution. We discuss the relation of the unintegrated parton distributions in subtractive regularization with the ordinary parton distributions. © 2007 Elsevier B.V. All rights reserved.