The Mu2e Trigger Menu expected performance

The Mu2e experiment at Fermilab searches for the charged-lepton flavor violating neutrino-less conversion of a negative muon into an electron in the field of an aluminum nucleus. The dynamics of such a process is well modelled by a two-body decay, resulting in a mono-energetic electron with an energy slightly below the muon rest mass. Mu2e is designed to reach a sensitivity on the ratio between the conversion rate and the capture rate of  6x1E-17 @ 90% C.L.. This will improve the current best limit by four orders of magnitude.

A very intense pulsed muon beam 1E10 µ/s is stopped on a target inside a very long solenoid where the detector is located. The detector consists of a tracker, a crystal calorimeter and an external veto for cosmic rays surrounding the solenoid. The trigger scheme consists of a series of software filters that run over the DAQ farm where an online reconstruction of the event is performed w/o any pre-selection (no L1 trigger). 

The main physics channels are selected by track-triggers that are capable to provide a very high efficiency (~99%) while keeping a formidable rejection at the level of a few 1,000. We present the design of the Mu2e trigger Menu and the expected trigger performance evaluated with the TDAQ prototype currently installed at Fermilab.