Jonathan R. Gaunt, W. James Stirling
We discuss the role of two different types of diagram in the proton-proton
double parton scattering (DPS) cross section - single and double perturbative
splitting graphs. Using explicit calculations of simple graphs from these
classes we show that the treatment of these graphs by the 'double PDF'
framework for describing the DPS cross section, introduced a number of years
ago by Snigirev and collaborators, is unsatisfactory. We suggest that a
contribution from single perturbative splitting graphs should be included in
the DPS cross section, albeit with a different geometrical prefactor to the
contribution from 'zero perturbative splitting' graphs.
View original:
http://arxiv.org/abs/1202.3056
No comments:
Post a Comment