Working Group on Muon to Electron Conversion
Contact person - W. Molzon
714-824-5987
wmolzon@uci.edu
The process of muon to
electron conversion in the field of a nucleus is an extremely sensitive
probe of muon and electron number violation. For negative muons Coulomb
bound to an appropriate nucleus, the conversion is coherent
over all the nucleons, resulting in an enhancement of this process with
respect to muon capture or decay. The AGS may be the best place to do
a new, extremely
sensitive search. The present upper limit, normalized
to muon capture, is about 10
. The SINDRUM 2 detector may
improve that limit by a factor of 10-100. An experiment with a
sensitivity of 10
would probe mass scales of a few thousand
TeV/c
, would have a major impact non standard model building, and
might well see something. Such an experiment
requires stopping 3 x 10
muons every
3 seconds for 10
seconds, detecting monoenergetic 105 MeV electrons
with an efficiency of 0.2, and measuring the
electron energy with a precision better than 1 MeV.
The experiment must be passively
and actively shielded from cosmic rays. A pulsed beam is required to ensure
that electrons from pion decay and from muon decay in flight are not a
source of background. A proposal exists for a muon beamline of novel design
and
a detector capable of doing this measurement at the Moscow Meson Factory
(the MELC beam and detector). Work on a muon source for a muon collider
is being pursued actively at BNL. This working group will study the
prospects for doing this experiment at the AGS, drawing on the ideas
of the MELC proposal, the work of the BNL muon collider group, and the
experience of the AGS staff. Depending on the interests of the group, other
rare muon processes, muon decay to electron and photon, for example,
may be studied.