Pion cloud and sea quark flavor asymmetry in the impact parameter representation
Abstract
We study large-distance contributions to the nucleon parton densities in the transverse coordinate (impact parameter) representation based on generalized parton distributions (GPDs). Chiral dynamics generates a distinct component of the partonic structure, located at momentum fractions x ~< M_pi/M_N and transverse distances b ~ 1/M_pi. We analyze the phenomenological "pion cloud" model of the flavor asymmetry dbar(x) - ubar(x) and quantify what fraction of the calculated asymmetry results from the universal large-distance region. Our findings indicate that a two-component picture of the nucleon's partonic structure, with a "core" antiquark distribution at b < b_core ~= 0.55 fm which vanishes at x -> 0 and the universal large-distance pion cloud, could naturally account for the x-dependence of the measured asymmetry.
Keywords
Cite
@article{arxiv.0811.3631,
title = {Pion cloud and sea quark flavor asymmetry in the impact parameter representation},
author = {M. Strikman and C. Weiss},
journal= {arXiv preprint arXiv:0811.3631},
year = {2009}
}
Comments
7 pages, 3 figures. To appear in proceedings of LIGHT CONE 2008 Relativistic Nuclear and Particle Physics, Mulhouse, France, July 7-11, 2008