# New limit on the lepton-flavour violating decay $\mu^{+} \to e^{+} \gamma$

@article{Adam2011NewLO, title={New limit on the lepton-flavour violating decay \$\mu^\{+\} \to e^\{+\} \gamma\$}, author={M. C. J. Adam and X. Bai and A. Baldini and E. Baracchini and C. Bemporad and G. Boca and P. Cattaneo and G. Cavoto and F. Cei and C. Cerri and A. Bari and M. Gerone and T. Doke and S. Dussoni and J. Egger and K. Fratini and Y. Fujii and L. Galli and G. Gallucci and F. Gatti and B. Golden and M. Grassi and D. Grigoriev and T. Haruyama and M. Hildebrandt and Y. Hisamatsu and F. Ignatov and T. Iwamoto and P. Kettle and B. Khazin and O. Kiselev and A. Korenchenko and N. Kravchuk and A. Maki and S. Mihara and W. Molzon and T. Mori and D. Mzavia and H. Natori and D. Nicol{\`o} and H. Nishiguchi and Y. Nishimura and W. Ootani and M. Panareo and A. Papa and R. Pazzi and G. Piredda and A. Popov and F. Renga and S. Ritt and M. Rossella and R. Sawada and F. Sergiampietri and G. Signorelli and S. Suzuki and F. Tenchini and C. Topchyan and Y. Uchiyama and R. Valle and C. Voena and F. Xiao and S. Yamada and A. Yamamoto and S. Yamashita and Y. Yudin and D. Zanello}, journal={Physical Review Letters}, year={2011}, volume={107}, pages={171801-171801} }

We present a new result based on an analysis of the data collected by the MEG detector at the Paul Scherrer Institut in 2009 and 2010, in search of the lepton flavour violating decay mu->e gamma. The likelihood analysis of the combined data sample, which corresponds to a total of 1.8 x 10**14 muon decays, gives a 90% C.L. upper limit of 2.4 x 10**-12 on the branching ratio of the mu->e gamma decay, constituting the most stringent limit on the existence of this decay to date.