Implications of the Muon g-2 result on the flavour structure of the lepton mass matrix

The confirmation of the discrepancy with the Standard Model predictions in the anomalous magnetic moment by theMuon g-2 experiment at Fermilab points to a low scale of new physics. Flavour symmetries broken at low energies can account for this discrepancy but these models are much more restricted, as they would also generate offdiagonal entries in the dipole moment matrix. Therefore, if we assume that the observed discrepancy in the muon g - 2 is explained by the contributions of a low-energy flavor symmetry, lepton flavour violating processes can constrain the structure of the lepton mass matrices and therefore the flavour symmetries themselves predicting these structures. We apply these ideas to several discrete flavour symmetries popular in the leptonic sector, such as Delta(27), A(4), and A(5) proportional to CP.

Automated summary

The Muon g-2 experiment at Fermilab confirmed the possibility of new physics at low energy scales and indicated that low energy could potentially explain the discrepancy with the Standard Model predictions of the anomalous magnetic moment. In addition, lepton flavor violating processes can also constrain the flavor symmetries predicting these structures, as shown by the experiment.