@article{a768cfbc6c604c7d815453ad0701f061,
title = "Search for lepton flavour violating muon decay mediated by a new light particle in the MEG experiment",
abstract = "We present the first direct search for lepton flavour violating muon decay mediated by a new light particle X, μ+→e+X,X→γγ. This search uses a dataset resulting from 7.5 × 10 14 stopped muons collected by the MEG experiment at the Paul Scherrer Institut in the period 2009–2013. No significant excess is found in the mass region 20–45 MeV/c2 for lifetimes below 40 ps, and we set the most stringent branching ratio upper limits in the mass region of 20–40 MeV/c2, down to O(10 - 11) at 90% confidence level.",
keywords = "GAMMA-RAY DETECTOR, CALIBRATION, PARAMETER, SYSTEM, TRACK",
author = "{MEG experiment} and Baldini, {A. M.} and F. Berg and M. Biasotti and G. Boca and Cattaneo, {P. W.} and G. Cavoto and F. Cei and M. Chiappini and G. Chiarello and C. Chiri and A. Corvaglia and {de Bari}, A. and {De Gerone}, M. and M. Francesconi and L. Galli and F. Gatti and F. Grancagnolo and M. Grassi and Grigoriev, {D. N.} and M. Hildebrandt and Z. Hodge and K. Ieki and F. Ignatov and R. Iwai and T. Iwamoto and S. Kobayashi and Kettle, {P. R.} and W. Kyle and N. Khomutov and A. Kolesnikov and N. Kravchuk and N. Kuchinskiy and T. Libeiro and Lim, {G. M.A.} and V. Malyshev and N. Matsuzawa and M. Meucci and S. Mihara and W. Molzon and Toshinori Mori and A. Mtchedilishvili and M. Nakao and H. Natori and D. Nicol{\`o} and H. Nishiguchi and M. Nishimura and S. Ogawa and R. Onda and A. Popov and Yudin, {Yu V.}",
note = "Funding Information: We are grateful for the support and co-operation provided by PSI as the host laboratory and to the technical and engineering staff of our institutes. This work is supported by DOE DEFG02-91ER40679 (USA); INFN (Italy); MIUR Montalcini D.M. 2014 n. 975 (Italy); JSPS KAKENHI numbers JP22000004, JP26000004, JP17J04114, and JSPS Core-to-Core Program, A. Advanced Research Networks JPJSCCA20180004 (Japan); Schweizerischer Nationalfonds (SNF) Grant 200021_137738 and Grant 200020_172706; the Russian Federation Ministry of Education and Science, and Russian Fund for Basic Research grant RFBR-14-22-03071. Publisher Copyright: {\textcopyright} 2020, The Author(s). Copyright: Copyright 2020 Elsevier B.V., All rights reserved.",
year = "2020",
month = sep,
day = "1",
doi = "10.1140/epjc/s10052-020-8364-1",
language = "English",
volume = "80",
journal = "European Physical Journal C",
issn = "1434-6044",
publisher = "Springer Nature",
number = "9",
}