English

Pion form factor at spacelike momentum transfers from local-duality QCD sum rule

High Energy Physics - Phenomenology 2008-11-26 v2

Abstract

We study the pion form factor in a broad range of spacelike momentum transfers within the local-duality version of QCD sum rules. We make use of the recently calculated two-loop double spectral density of the <AVA><AVA> correlator including O(1) and O(αs)O(\alpha_s) terms, which allows us to give predictions for the pion form factor and to study the interplay between the nonperturbative and perturbative contributions to the pion form factor without any reference to the pion distribution amplitude. Our results demonstrate the dominance of the nonperturbative contribution to the form factor up to relatively large values of the momentum transfer: namely, the nonperturbative O(1) term, which provides the 1/Q41/Q^4 power correction, gives more than half of the pion form factor in the region Q220Q^2 \le 20 GeV2^2.

Keywords

Cite

@article{arxiv.0710.5461,
  title  = {Pion form factor at spacelike momentum transfers from local-duality QCD sum rule},
  author = {Victor Braguta and Wolfgang Lucha and Dmitri Melikhov},
  journal= {arXiv preprint arXiv:0710.5461},
  year   = {2008}
}

Comments

Revtex, 7 pages, references added, version to appear in Phys. Lett. B