Neutrino mixings from a U(2) flavour symmetry Original Research Article

We extend a previously developed description of the flavour parameters in the charged fermion sector, based on a U(2) flavour symmetry, to include two main features of the neutrino sector seemingly implied by recent data: a large mixing angle θμτ and a large hierarchy in the neutrino squared mass differences. A unified description of quark and lepton masses and mixings emerges. The neatest quantitative predictions are for elements of the unitary mixing matrix in the lepton sector |Vμll| = Ve3lVμ3l = Ve2lVτ3l = memμ, which go together with the analogous relations in the quark sector VubqVcbq = mumc, VtdqVtsq = mdms.