Hadronic contribution to the Muon 𝑔 − 2 with emphasis on photon-photon fusion processes

Abstract

The current status of muon 𝑔 − 2 is briefly reviewed, particularly for its hadronic contributions, hadronic vacuum polarization (HVP) and hadronic light-by-light (HLbL), using the data-driven and dispersive approach. As the subprocess of HLbL, the photon-photon fusion to hadrons, especially to π+π−π0 process, is studied in detail.