Double Parton Distributions Incorporating Perturbative QCD Evolution and Momentum and Quark Number Sum Rules

Understand

It is anticipated that hard double parton scatterings will occur frequently in the collisions of the LHC, producing interesting signals and significant backgrounds to certain single scattering processes.

• For double scattering processes in which the same hard scale t = ln(Q^2) is involved in both collisions, we require the double parton distributions (dPDFs) D_h^{j_1j_2}(x_1,x_2;t) in order to make theoretical predictions of their rates and properties.
• We describe the development of a new set of leading order dPDFs that represents an improvement on approaches used previously.
• First, we derive momentum and number sum rules that the dPDFs must satisfy.