We study the factorization relations between quasi gluon GPDs and twist-2 GPDs. The perturbative coefficient functions are obtained at one-loop level. They free from any collinear- or I.R. divergences. Unlike case of quark one-loop, we have to add ghost contributions for in order obtain gauge-invariant results. In general, operators will be mixed beyond tree-level. Our work shows that mixing pa...

In this work, we give a detailed discussion for QCD factorization involved the complete chirally enhanced power corrections in the heavy quark limit for B decays to two light pseudoscalar mesons, and present some detailed calculations of radiative corrections at the order of αs. We point out that the infrared finiteness of the vertex corrections in the chirally enhanced power corrections requir...

Abstract. Recent measurements of diffractive dijet and charm quark production in electron-proton collisions using the H1 detector at HERA are presented, where the exchanged photon is either almost real or highly virtual. The data are compared with leading and next-to-leading order QCD calculations based on the diffractive parton distributions obtained from a recent DGLAP QCD analysis of H1 incl...

These lectures on QCD stress the theoretical elements that underlie a wide range of phenomenological studies, particularly gauge invariance, renormalization, factorization and infrared safety. The three parts cover the basics of QCD, QCD at tree level and higher order corrections. Lectures given at the 2004 European School of High-Energy Physics, St. Feliu de Guı́xols, Barcelona, Spain, 30 May –...