We measured the charge ratio and the polarization of the high-energy cosmic-ray muons arriving with zenith angles from 0° to 90° in the large underground water Cherenkov detector, Kamiokande II. The charge ratio [$R\left(\frac{{\mu }^{+}}{{\mu }^{-}}\right)$] and the polarization ($P_0$) are found to be 1.37±0.06(stat)±0.01(syst) and 0.26±0.04(stat)±0.05(syst), respectively, at the sea-level momentum of 1.2 TeV/c. This result for the charge ratio is in good agreement with those previously obtained in experiments using magnetic spectrometers at sea level and underground. This is the first measurement of the polarization of the cosmicray muons in the TeV region.

• Received 4 March 1991

DOI:https://doi.org/10.1103/PhysRevD.44.617