Multiple parton scattering in nuclei: gauge invariance
Abstract
Within the framework of a generalized collinear factorization for multiple parton scattering in nuclear medium, twist-4 contributions to DIS off a large nucleus can be factorized as a convolution of hard parts and two-parton correlation functions. The hard parts for the quark scattering in the light-cone gauge correspond to interaction with a transverse (physical) gluon in the target, while they are given by the second derivative of the cross section with a longitudinal gluon in the covariant gauge. We provide a general proof of the equivalence of the hard parts in the light-cone and covariant gauge. We further demonstrate the equivalence in calculations of twist-4 contributions to semi-inclusive cross section of DIS in both lowest order and next leading order. Calculations of the nuclear transverse momentum broadening of the struck quark in the light-cone and covariant gauge are also discussed.
Cite
@article{arxiv.0805.4030,
title = {Multiple parton scattering in nuclei: gauge invariance},
author = {Zuo-tang Liang and Xin-Nian Wang and Jian Zhou},
journal= {arXiv preprint arXiv:0805.4030},
year = {2009}
}
Comments
23 pages with 4 figures