English

Comment on "Nucleon spin-averaged forward virtual Compton tensor at large Q^2"

High Energy Physics - Phenomenology 2018-09-12 v2 Nuclear Theory Atomic Physics

Abstract

In recent work, Hill and Paz apply the operator product expansion to forward doubly virtual Compton scattering. The resulting large-Q2Q^2 form of the amplitude W1(0,Q2)W_1(0,Q^2) is compatible with the one we obtain by extrapolation of low-Q2Q^2 results from a chiral effective field theory, providing support for our approach. That paper also presents a result for the two-photon contribution to the Lamb shift in muonic hydrogen that has a much larger uncertainty than in previous work. We show that this an overestimate arising from the inclusion of the proton pole term in the subtracted dispersion relation for W1W_1.

Keywords

Cite

@article{arxiv.1708.09341,
  title  = {Comment on "Nucleon spin-averaged forward virtual Compton tensor at large Q^2"},
  author = {Michael C. Birse and Judith A. McGovern},
  journal= {arXiv preprint arXiv:1708.09341},
  year   = {2018}
}

Comments

3 pages; version accepted for publication

R2 v1 2026-06-22T21:28:06.652Z