Dr. Stefan Ritt (Paul Scherrer Institut (PSI), Switzerland)
" Fast waveform digitizing for the search of the mu+ -> e+ gamma decay "
The search for the lepton-flavour violating decay mu+ -> e+ gamma is both attractive and very challenging. It is complementary to direct searches for New Physics at colliders and has a reach up to several 100 TeV, well beyond any current and future accelerator. The challenge in this search at a level down to 10^-14 with the MEG experiment is the huge background coming from normal muon decay, which requires cutting edge detector technology and electronics. For this purpose the Switched Capacitor Array (SCA) chip DRS4 has been developed at PSI, Switzerland. With a sampling rate of 5 GSPS at 12 bits of resolution at a power consumption of 15 mW per channel, this technology allows excellent energy and time resolutions down to a few pico seconds for systems with more than 10,000 channels. This seminar shows the latest result from the MEG experiment and the ongoing work for the MEG II upgrade, which seeks to improve the current limit by one more order of magnitude. It covers the theory behind SCA chips and explains its advantages and limitations, with a special emphasis on cosmic ray experiments.