English

Nucleon Spin Content from Elastic Form Factor Data

High Energy Physics - Phenomenology 2007-05-23 v1

Abstract

I use the formalism of skewed parton distributions (SPD) to describe elastic form factors of the nucleon. The results are consistent with approximate dipole behavior of GMp(Q2)G_{Mp}(Q^2) and recent JLab data for the ratio of the proton form factors GEp/GMpG_{Ep}/G_{Mp} at Q23.5Q^2\leq 3.5 GeV2^2. Using the Angular Momentum Sum Rule, I obtain a numerical estimate for the valence quark contributions to the nucleon spin at the level of 50%, with their orbital angular momentum {\it included}. When combined with polarized DIS measurements, this result indicated that the orbital angular momentum of quarks contributes about 25% to the nucleon spin.

Keywords

Cite

@article{arxiv.hep-ph/9910565,
  title  = {Nucleon Spin Content from Elastic Form Factor Data},
  author = {Andrei V. Afanasev},
  journal= {arXiv preprint arXiv:hep-ph/9910565},
  year   = {2007}
}

Comments

6 pages, 3 eps-figures, uses sprocl.sty. Invited talk at the INT/JLab Workshop `Exclusive and Semiexclusive Processes at High Momentum Transfer', Newport News, VA, May 20-22, 1999