particles
Count: 836s
   leptons
  Count: [*] 6s
     1.1 e- 1897
    Count: -
     1.2 nu(e) C.L. Cowan et al., 1956
    Count: -
     2.1 mu- 1930's
    Count: -
     2.2 nu(mu) 1962
    Count: -
     3.1 tau- M.L. Perl et al., 1975
    Count: -
     3.2 nu(tau)
    Count: -