Physical factorisation scheme for PDFs for non-inclusive applications
E. G. De Oliveiraa, Alan D. Martin, M. G. Ryskin · 2013
We introduce the physical factorisation scheme, which is necessary to describe ob-servables which are not completely inclusive. We derive the formulae for NLO DGLAP evolution in this scheme, and also for the ‘rotation ’ of the conventional MS PDFs into the physical representation. Unlike, the MS prescription, where, for example, the gluon PDF at NLO obtains an admixture of the quark-singlet PDF, and vice-versa, the physical approach does not mix parton PDFs of different types. That is, the physical approach retains the precise quantum numbers of each PDF. The NLO corrections to DGLAP evolution in the physical scheme are less than those in the MS case, indicating a better convergence of the perturbative series. 1