LARGE-SCALE ANISOTROPY OF THE COSMIC-RAY MUON FLUX IN KAMIOKANDE

The large-scale anisotropy of cosmic-ray primaries in the celestial co ordinate was studied using cosmic-ray muons recorded in a large water Cherenkov detector, Kamiokande. The right-ascension distribution of th e muon arrival directions deviated from an isotropic distribution with a 2.8 standard deviation, and agreed well with the first harmonics wi th an amplitude of (5.6 +/- 1.9) x 10(-4) and a phase of 8.0 degrees /- 19.1 degrees. This is the deepest underground observation of the la rge-scale anisotropy of cosmic rays, and agrees with observations with other underground experiments and extensive air-shower array experime nts.