Search for the Lepton Flavour Violating Decay $μ^{+} \to e^+ γ$ with the Full Dataset of the MEG Experiment
The final results of the search for the lepton flavour violating decay $μ^{+} \rightarrow {\rm e^{+}} γ$ based on the full dataset collected by the MEG experiment at the Paul Scherrer Institut in the period 2009--2013 and totalling $7.5\times 10^{14}$ stopped muons on target are presented. No significant 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 $BR( μ^{+} \rightarrow {\rm e^{+}} γ) < 4.2 \times 10^{-13}$ (90\%\ confidence level) is established, which represents the most stringent limit on the existence of this decay to date.
hep-ex↗