Neutrinoless Muon-to-Positron Conversion at Mu2e

The Mu2e experiment at Fermilab will search for coherent neutrinoless muon-to-electron conversion interacting with an Aluminum-27 nucleus at a sensitivity 10,000 times higher than the current upper bound. A secondary physics goal of the experiment is the search for neutrinoless muon-to-positron conversion. Not only would this process violate lepton flavor conservation at rates far greater than allowed by the Standard Model, but also violate lepton number conservation. Like neutrinoless double beta decay, muon-to-positron conversion would demonstrate that neutrinos are Majorana particles. Mu2e is also expected to be several orders of magnitude more sensitive than past experiments to muon-to-positron conversion. To achieve this sensitivity, it is important that we thoroughly understand the sources of background positrons in the detection environment. We will discuss detailed simulations of the background processes and predictions for the Mu2e sensitivity to muon-to-positron conversion.