Large [θ.sup.v.sub.13] and unified description of quark and lepton mixing matrices

We present a revised version of the so-called "yukawaon model", which was proposed for the purpose of a unified description of the lepton mixing matrix [U.sub.PMNS] and the quark mixing matrix [V.sub.CKM]. It is assumed from a phenomenological point of view that the neutrino Dirac mass matrix [M.sub.D] is given with a somewhat different structure from the charged lepton mass matrix [M.sub.e], although [M.sub.D] = [M.sub.e] was assumed in the previous model. As a result, the revised model predicts a reasonable value [sin.sup.2]2[θ.sub.13] ~ 0.07 with keeping successful results for other parameters in [U.sub.PMNS] as well as [V.sub.CKM] and quark and lepton mass ratios.