English

Pion and Kaon box contribution to $a_{\mu}^{\text{HLbL}}$

High Energy Physics - Phenomenology 2022-04-21 v2 Nuclear Theory

Abstract

We present an evaluation of the π±\pi^\pm and K±K^\pm box contributions to the hadronic light-by-light piece of the muon's anomalous magnetic moment, aμa_\mu. The calculation of the corresponding electromagnetic form factors (EFFs) is performed within a Dyson-Schwinger equations (DSE) approach to quantum chromodynamics. These form factors are calculated in the so-called rainbow-ladder (RL) truncation, following two different evaluation methods and, subsequently, in a further improved approximation scheme which incorporates meson cloud effects. The results are mutually consistent, indicating that in the domain of relevance for aμa_\mu the obtained EFFs are practically equivalent. Our analysis yields the combined estimates of aμπ±box=(15.6±0.2)×1011a_\mu^{\pi^\pm-box}=-(15.6\pm 0.2)\times 10^{-11} and aμK±box=(0.48±0.02)×1011a_\mu^{K^\pm-\text{box}}=-(0.48\pm 0.02)\times 10^{-11}, in full agreement with results previously obtained within the DSE formalism and other contemporary estimates.

Keywords

Cite

@article{arxiv.2112.13916,
  title  = {Pion and Kaon box contribution to $a_{\mu}^{\text{HLbL}}$},
  author = {Ángel Miramontes and Adnan Bashir and Khépani Raya and Pablo Roig},
  journal= {arXiv preprint arXiv:2112.13916},
  year   = {2022}
}

Comments

Updated error estimates. 10 pages, 2 figures, 2 tables