Leptogenesis, Sym m etry and 13
R. N. M ohapatra · 2005
W eshow thatin theorieswhereneutrinom assesarisefrom typeIseesaw form ulawith threeright handed neutrinos and where large atm ospheric m ixing angle owes its origin to an approxim ate leptonic � � interchange sym m etry,the prim ordiallepton asym m etry ofthe Universe, �l can