A MACRO sampler

Abstract

We present results from approximately 2 years running with the MACRO detector. Most of these data were taken with one of the six supermodules of the final detector in operation. Using a sample of 1.8×106 muons with E≳1.4 TeV we have searched for an excess of muons of celestial origin over cosmic ray background. No evidence for steady point sources was found. The upper limit on the muon flux at 95% CL is typically 2×10−12 cm−2 sec−2. No evidence for time modulated point sources was found. The muon multiplicity distribution favors a ‘‘light’’ composition for cosmic ray primaries with ≊75% protons above ∼103 TeV. We have also searched for neutrino bursts from supernovae in our Galaxy. None were observed during the period Oct. 1989 to Feb. 1992. Our sensitivity to neutrino bursts from collapsing stars extends to ≊60% of the stars in the Galaxy.