English

Re-examining valence quark spin distributions

High Energy Physics - Phenomenology 2017-06-21 v2 Nuclear Theory

Abstract

The observed deep inelastic nucleon spin asymmetries A1p,nA_{1}^{p,n} and the spin dependent quark distributions break SU(6) spin - flavour symmetry. In quark models two mechanisms for breaking SU(6) symmetry are well known: the hyperfine interaction and the pion cloud of the nucleon. I re-evaluate these mechanisms and show how the breaking of SU(6) in each case affects spin dependent valence quark distributions of the proton. In particular I investigate the properties of these mechanisms in the kinematic region 0.3<x<0.70.3 < x < 0.7 and attempt to test these against known data. Both mechanisms are able to explain the quantitative features of the spin asymmetries.

Keywords

Cite

@article{arxiv.1702.05152,
  title  = {Re-examining valence quark spin distributions},
  author = {A. I. Signal},
  journal= {arXiv preprint arXiv:1702.05152},
  year   = {2017}
}

Comments

27 pages, 6 figures. Revised version accepted for publication in Physical Review D

R2 v1 2026-06-22T18:20:42.756Z