Construction of the MuPix HV-CMOS tracker and background suppression for Mu3e

The Mu3e experiment is designed to search for charged lepton flavour violation by looking for the forbidden mu e+e-e+ decay. The observations of neutrino oscillations have revealed that lepton flavour isn't a conserved quantity, however despite previous searches it has never been found in charged leptons. In the standard model this decay is suppressed to unobservable levels however many models beyond the standard model predict much higher branching fractions.
The Mu3e detector is designed to be able to have a branching ratio sensitivity of <10-16, this is an improvement of four orders of magnitude over the current limit from SINDRUM.
The University of Liverpool will play a major role in the construction of the MuPix HV-CMOS tracker for the experiment.
As a research student the roles that will be undertaken as a active member of the team is contributing to the assembly and quality assurance of the MuPix tracker. This work will be done alongside simulations studies which will improve the rejection of one of the main background processes. Michel decays with an internal photon conversion have the same final state in the detector, but a total energy of the 3 electrons below the muon mass. The key way to reduce this background is by understanding the momentum measurements from the MuPix tracker.
I will also take part in test beams to characterise the MuPix sensor for final detector.