David Hitlin (California Institute of Technology)
We present the status of Mu2e experiment for the search of coherent, neutrino-less conversion of muons into electrons in the field of a nucleus to a few parts in 10⁻¹⁷, a sensitivity improvement of a factor of 10⁴ over existing limits. The Mu2e experiment will be hosted by Fermilab at a new muon campus. It will use a complex of solenoids to collect and transport the muons, produced when the 8 GeV pulsed proton beam hits the tungsten production target. The last solenoid in the complex will allow for the measurement of the momentum of the electrons produced by the muons trapped into the muon stopping targets. To this goal, Mu2e will adopt a challenging detector system. We present a detailed description and the expected performance. The central part of the detector is a low-mass straw tube tracker immersed in a 1 Tesla uniform magnetic field and placed in vacuum (10⁻⁴ torr) to efficiently identify 105 MeV/c electrons, with a resolution of the order of 100 KeV/c, and to reject a large amount of background hits (average hit rate of ~15 kHz/cm²) within a high radiation environment (peak hit rate of ~3 MHz/cm²). A BaF₂ crystal calorimeter, downstream of the tracker, will provide particle ID, to further reduce backgrounds, energy and time measurements. The large detector area will be extensively covered by multi-layer scintillation counters to reject, at the level of 10⁻⁴, cosmic rays that could mimic signal tracks.