  The Mu2e experiment will search for a Standard Model violating rate of
neutrinoless conversion of a muon into an electron in the presence of an
aluminum nucleus. Observation of this charged lepton flavor violating process
would be an unambiguous sign of new physics. Mu2e will improve upon previous
searches for this process by four orders of magnitude. This requires the
world's highest-intensity muon beam, a detector system capable of efficiently
reconstructing the 105 MeV/c conversion electron signal, and minimizing
sensitivity to background events. A pulsed 8 GeV proton beam strikes a target,
producing pions that decay into muons. Beam outside the pulse must be
suppressed to $< 10^{-10}$ to reduce beam-related backgrounds. The muon beam is
guided from the production target along the transport system and onto the
aluminum stopping target. Conversion electrons leave the stopping target and
propagate inside a solenoidal magnetic field to the tracker and electromagnetic
calorimeter. The tracker is a system of straw tube panels filled with Ar/CO$_2$
at 1 atm that tracks particles inside of a solenoidal B-field and measures
their momenta with $\sim100$ keV/$c$ resolution to resolve signal events from
decay-in-orbit backgrounds. The CsI calorimeter provides $E/p$ and is used to
seed the track reconstruction algorithm with $\sigma_E /E \sim{}10\%$ and
$\sigma_t<500~\rm{ps}$. Additionally, a novel cosmic ray veto with greater than
99.99\% efficiency brings the expected number of background events to fewer
than one over three years of running. To normalize the experiment, the stopping
target monitor measures the rate of capture photons from muons incident on the
stopping target by using a system of high-purity germanium and lanthanum
bromide scintillators.
