Search for Steady, Modulated, and Variable Cosmic Ray Sources Using Underground Muons in MACRO

Abstract

Using a sample of 38.5 million underground muons collected by the MACRO detector we have performed an all-sky search for pointlike sources producing excesses of muons above the expected background. The d.c. muon flux upper limit at the Earth coming from selected sources is of the order of 10^-13 cm^-2 s^-1 or less. Futhermore we discuss searches for possible modulated and variable sources of muons using different techniques.