Majorana mass of the electron-muon Dirac neutrino and the fermion masses

Abstract

The left-handed electron and muon neutrinos are considered to be Majorana neutrinos with equal mass. They have oppositeCP parities and are equivalent to a single Dirac neutrino. These neutrinos are shown to have a Majorana mass of about 6.5 eV. The relatively large mass of their charged leptons is due to their γ5 coupling with the Higgs scalars By expressing the Higgs scalars as Clebsch-Gordon type of combinations ofZ andD neutral vector bosons with appropriate quantum numbers, it is shown that 2memμ/(me2+mμ2)=(gv/gA)eμ2, wheregv andgA are the vector and axial vector coupling constants, respectively, ofZ (orD) with the leptonse and μ. Weinberg mixing parametersxL=e2/gL2 andxR=e2/gR2 are determined to be 0.2254 and 0.2746, respectively. In the quark sector the Cabibbo angle is about 13°11′ and the masses oft andb quarks are found to be respectively 134.2 and 4.69 GeV.