Search for the lepton flavour violating decay μ+→ e +γ with the full dataset of the MEG experiment: MEG Collaboration

The final results of the search for the lepton flavour violating decay mu(+) -> e(+)gamma based on the full dataset collected by the MEG experiment at the Paul Scherrer Institut in the period 2009-2013 and totalling 7.5x10(14) stopped muons on target are presented. Nosignificant excess of events is observed in the dataset with respect to the expected background and a new upper limit on the branching ratio of this decay of B(mu(+) -> e(+) gamma) < 4.2 x 10(-13) (90 % confidence level) is established, which represents the most stringent limit on the existence of this decay to date.