DE FLORIAN daniel Enrique
Collinear Splitting, Parton Evolution and the Strange-Quark Asymmetry of the Nucleon in NNLO QCD
STEFANO CATANI, DANIEL DE FLORIAN, G.RODRIGO, WERNER VOGELSANG
NUCLEAR PHYSICS B
ELSEVIER SCIENCE BV
Año: 2004 vol. 135 p. 188 - 188
We consider the collinear limit of QCD amplitudes at one-loop order, and their factorization properties directly in colour space. These results apply to the multiple collinear limit of an arbitrary number of QCD partons, and are a basic ingredient in many higher-order computations. In particular, we discuss the triple collinear limit and its relation to flavour asymmetries in the QCD evolution of parton densities at three loops. As a phenomenological consequence of this new effect, and of the fact that the nucleon has non-vanishing quark valence densities, we study the perturbative generation of a strange?antistrange asymmetry in the nucleon?s sea.