1202.3794 (Aneesh V. Manohar et al.)

A QCD Analysis of Double Parton Scattering: Color Correlations,
Interference Effects and Evolution    [PDF]

Aneesh V. Manohar, Wouter J. Waalewijn

We derive a factorization formula for the double Drell-Yan cross section in
terms of double parton distribution functions (dPDFs). Diparton spin and color
correlations and parton-exchange interference terms contribute, even for
unpolarized beams. Soft radiation effects are nontrivial for the color
correlation and interference contributions, and are described by
non-perturbative soft functions. We provide a field-theoretic definition of the
quark dPDFs and study some of their basic properties, including discrete
symmetries and their interpretation in a non-relativistic quark model. We
calculate the renormalization group evolution of the quark dPDFs and of the
soft functions. The evolution receives contributions from both ultraviolet and
rapidity divergences. We find that color correlation and interference effects
are Sudakov suppressed, greatly reducing the number of dPDFs needed to describe
double parton scattering at high energy experiments.

View original: http://arxiv.org/abs/1202.3794