Laser polarized muonic helium

We have formed polarized muonic He3 by stopping unpolarized negative muons in a gaseous He3 target which was polarized by spin exchange with laser optically pumped Rb vapor. We measured PN, the resulting muon polarization normalized to the nuclear polarization of the He3. In addition to being a property that characterizes the muon cascade in the -3He system, PN is of practical value for future experiments on nuclear muon capture. Our result, PN=0.072±0.008, is a factor of 2 smaller than predicted by simple atomic cascade theory.