Expected performance of the Mu2e trigger for Cosmic µ

The Mu2e experiment, currently under construction at Fermi National Laboratory, will

search for CLFV (charged lepton flavor violation) via neutrinoless muon to electron conversion

in the field of an aluminum nucleus. Muons will be directed onto an aluminum target and

captured by aluminum atoms. If the captured muons decay via muon-to-electron conversion, the

resulting electron energy will be 104.97MeV. A tracker and calorimeter will then reconstruct

tracks and reveal the decay products of the captured muons. In addition to conversion electrons

and other decays, the tracker will contend with backgrounds such as protons, Compton

electrons, and uncaptured muons, as well as atmospheric muons. Produced when cosmic rays

collide with the upper atmosphere, atmospheric muons arrive at Earth’s surface at nearly the

speed of light. The beam cycle of Mu2e will include periods where both signal and background

are absent from the tracker, leaving primarily cosmics. This provides an opportunity to analyze

cosmics and improve vetoing algorithms; in addition, cosmics are useful in calibrating the

tracker due to their extremely high momentum. This poster will report on the many ways

cosmics will be studied in Mu2e, and will detail the specifics of the tracking and particle

reconstruction process.