Detectors for these particles are used to determine whether archaeological sites contain tombs.  
Detectors for these particles are used to determine whether archaeological sites contain tombs.  In the 1970's, physicists working at the European Center for Nuclear Research were surprised when they fired neutrinos at a proton and created two of these particles, one positive and one negative.  They can be artificially produced by hitting a graphite target with a proton stream accelerated to 80% of the speed of light, which produces the pions that eventually decay to these particles.  Originally thought to be mesons, they were first discovered by Carl Anderson while he was studying cosmic radiation.  FTP, name these leptons with a lifetime of about 2.2 microseconds and a mass roughly 207 times that of an electron.
Detectors for these particles are used to determine whether archaeological sites contain tombs.  
muons