Book Description

The MEG experiment is the latest in a series of progressively more precise rare decay searches designed to exploit an observation of [mu]+[superscript] [arrow right] e+[superscript] [gamma] or lack thereof as a sensitive low energy probe of new physics. A search for [mu]+[superscript] [arrow right] e+[superscript] [gamma] is performed using the 43 days worth of data acquired by the MEG experiment during 2009. To best estimate the number of signal events in the data, a maximum likelihood fit is performed. A 90% confidence interval is then constructed using the Feldman-Cousins technique. The analysis is done blind by hiding signal-like events until the selection cuts and likelihood function are settled upon. The result is consistent with the null hypothesis and an upper limit is set: BR([mu]+[superscript] [arrow right] e+[superscript] [gamma]