English

Dispersive approach to hadronic light-by-light scattering

High Energy Physics - Phenomenology 2015-06-18 v2 High Energy Physics - Experiment High Energy Physics - Lattice Nuclear Theory

Abstract

Based on dispersion theory, we present a formalism for a model-independent evaluation of the hadronic light-by-light contribution to the anomalous magnetic moment of the muon. In particular, we comment on the definition of the pion pole in this framework and provide a master formula that relates the effect from pi pi intermediate states to the partial waves for the process gamma^* gamma^* --> pi pi. All contributions are expressed in terms of on-shell form factors and scattering amplitudes, and as such amenable to an experimental determination.

Keywords

Cite

@article{arxiv.1402.7081,
  title  = {Dispersive approach to hadronic light-by-light scattering},
  author = {Gilberto Colangelo and Martin Hoferichter and Massimiliano Procura and Peter Stoffer},
  journal= {arXiv preprint arXiv:1402.7081},
  year   = {2015}
}

Comments

33 pages, 4 figures; version accepted for publication in JHEP, improved presentation, including non-diagonal kernels for the S-waves