Cosmic ray muons at a depth of 754 hg/cm2 in the Kolar gold mines

A telescope of area 4m2, consisting of horizontal layers of plastic scintillators, neon flash tubes and absorbers was operated at a depth of 754 hg/cm2 in the Kolar Gold Mines. New values for the vertical intensities of muon have been obtained from observations of the angular distribution over the slant depths approximately 750-2300 hg/cm2 and are compared with the existing measurements. From the angular distribution observed, it is concluded that muons are produced wholly through the decay of pions and kaons up to energies of the order of 1 TeV. A value of 0.3+-0.2 is estimated for the K/π ratio at production, for muon energies around 500 GeV. A decoherence distribution has been obtained for parallel muon events up to distances of the order of 10m. From this, it is concluded that the average Psub(t) of the parents of muons of energy approximately 250 GeV is of the order of 0.3 GeV/c. From an analysis of rock showers, the cross section obtained for inelastic interaction of muons of mean energy 100 GeV is (3.8+-1.5)x10-30 cm2/nucleon. (author)