"Slow" Muon Depolarization in a Single Crystal of Gypsum (CaSO4· 2H2O)

Abstract

Polarized muons were stopped in a single crystal of CaS${\mathrm{O}}_4$ · 2${\mathrm{H}}_2$O placed in a magnetic field. Muon precession displayed a beat behavior and a "slow" -μsec-decrease of the muon spin polarization; these effects were found to be strongly dependent on crystal orientation in the field. Consistent explanation of the results was achieved by assuming that the muon occupied a normal proton site, and by considering the local field effects due to the dipole-dipole interaction of muon-proton pairs.