Leptons Mass:

me = 0.5109989461(31) MeV,

mτ /me = (2π /3α)[(π2/6) +1]2,

mμ /me = (2π /3α)[(π2/6) -1]2;

mνe = 0.00249988 eV,

mντ /mνe = (2π /108α)[1+ (π2/24)]2,

mνμ /mνe = (2π /108α)[1- (π2/24)]2.

α = 1/137.035999139(31).