Abstract

Double parton scattering (DPS) – the process in which two distinct pairs of partons hard scatter in an individual proton-proton collision –represents an important background to certain Higgs and new physics signals, and can reveal novel information about the proton structure. I will show that a long-established framework for describing the total DPS cross section appears to contain some unsatisfactory features, examine the various types of graph that can potentially contribute to the DPS cross section, and suggest an alternative formula for the DPS cross section (although I will explain that there still appear to be some remaining issues with this formula). I will also discuss interference and correlated parton contributions to DPS , and the Sudakov suppression of colour interference contributions.