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

none84siThe 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.Baldini, A.M.; Bao, Y.; Baracchini, E.; Bemporad, C.; Berg, F.; Biasotti, M.; Boca, G.; Cascella, M.; Cattaneo, P.W.; Cavoto, G.; Cei, F.; Cerri, C.; Chiarello, G.; Chiri, C.; Corvaglia, A.; de Bari, A.; De Gerone, M.; Doke, T.; D’Onofrio, A.; Dussoni, S.; Egger, J.; Fujii, Y.; Galli, L.; Gatti, F.; Grancagnolo, F.; Grassi, M.; Graziosi, A.; Grigoriev, D.N.; Haruyama, T.; Hildebrandt, M.; Hodge, Z.; Ieki, K.; Ignatov, F.; Iwamoto, T.; Kaneko, D.; Kang, T.I.; Kettle, P.-R.; Khazin, B.I.; Khomutov, N.; Korenchenko, A.; Kravchuk, N.; Lim, G.M.A.; Maki, A.; Mihara, S.; Molzon, W.; Mori, Toshinori; Morsani, F.; Mtchedilishvili, A.; Mzavia, D.; Nakaura, S.; Nardò, R.; Nicolò, D.; Nishiguchi, H.; Nishimura, M.; Ogawa, S.; Ootani, W.; Orito, S.; Panareo, M.; Papa, A.; Pazzi, R.; Pepino, A.; Piredda, G.; Pizzigoni, G.; Popov, A.; Raffaelli, F.; Renga, F.; Ripiccini, E.; Ritt, S.; Rossella, M.; Rutar, G.; Sawada, R.; Sergiampietri, F.; Signorelli, G.; Simonetta, M.; Tassielli, G.F.; Tenchini, F.; Uchiyama, Y.; Venturini, M.; Voena, C.; Yamamoto, A.; Yoshida, K.; You, Z.; Yudin, Yu. V.; Zanello, D.Baldini, A. M.; Bao, Y.; Baracchini, E.; Bemporad, C.; Berg, F.; Biasotti, M.; Boca, Gianluigi; Cascella, M.; Cattaneo, P. W.; Cavoto, G.; Cei, F.; Cerri, C.; Chiarello, G.; Chiri, C.; Corvaglia, A.; DE BARI, Antonio; De Gerone, M.; Doke, T.; D’Onofrio, A.; Dussoni, S.; Egger, J.; Fujii, Y.; Galli, L.; Gatti, F.; Grancagnolo, F.; Grassi, M.; Graziosi, A.; Grigoriev, D. N.; Haruyama, T.; Hildebrandt, M.; Hodge, Z.; Ieki, K.; Ignatov, F.; Iwamoto, T.; Kaneko, D.; Kang, T. I.; Kettle, P. R.; Khazin, B. I.; Khomutov, N.; Korenchenko, A.; Kravchuk, N.; Lim, G. M. A.; Maki, A.; Mihara, S.; Molzon, W.; Mori, Toshinori; Morsani, F.; Mtchedilishvili, A.; Mzavia, D.; Nakaura, S.; Nardo', Roberto; Nicolò, D.; Nishiguchi, H.; Nishimura, M.; Ogawa, S.; Ootani, W.; Orito, S.; Panareo, M.; Papa, A.; Pazzi, R.; Pepino, A.; Piredda, G.; Pizzigoni, G.; Popov, A.; Raffaelli, F.; Renga, F.; Ripiccini, E.; Ritt, S.; Rossella, M.; Rutar, G.; Sawada, R.; Sergiampietri, F.; Signorelli, G.; Simonetta, M.; Tassielli, G. F.; Tenchini, F.; Uchiyama, Y.; Venturini, M.; Voena, C.; Yamamoto, A.; Yoshida, K.; You, Z.; Yudin, Y. u. V.; Zanello, D

Test and characterisation of SiPMs for the MEGII high resolution Timing Counter

The MEGII Timing Counter will measure the positron time of arrival with a resolution of ~ 30 ps relying on two arrays of scintillator pixels read out by 6144 Silicon Photomultipliers (SiPMs) from AdvanSiD. They are characterised, measuring their breakdown voltage, to assure that the gains of the SiPMs of each pixel are as uniform as possible, to maximise the pixel resolution. Gain measurements have also been performed