Yukawaon model in the quark sector and nearly tribimaximal neutrino mixing

For the purpose of deriving the observed nearly tribimaximal neutrino mixing, a possible yukawaon model in the quark sector is investigated. Five observable quantities (2 up-quark mass ratios and 3 neutrino mixing parameters sin22θatm, tan2θsolar and |U13|) are excellently fitted by two parameters (one in the up-quark sector and another one in the right-handed Majorana neutrino sector).