Precise measurement of the hyperfine-structure interval and Zeeman effect in the muonic helium atom

Measurements of the hyperfine Zeeman transitions (..delta..M/sub ..mu../ = +- 1, ..delta..M/sub J/ = 0) in the ground state of the muonic helium atom (/sup 4/He ..mu../sup -/e/sup -/) at magnetic fields of 11.5 and 13.6 kG have yielded values for the hfs interval, ..delta nu.. = 4465.004 (29) MHz (6.5 ppm) and for the negative-muon magnetic moment, ..mu../sub mu-//..mu../sub p/ = 3.183 28(15) (47 ppm). The theoretical value for ..delta nu.., including relativistic, radiative, and recoil contributions, agrees with our measured value but is much less precise because of inadequate knowledge of the Schroedinger wave function.