Mass-matrix ansatz and constraints onBs0−B¯s0mixing in 331 models

Abstract

Comparing the theoretically predicted and measured values of the mass difference of the ${B}_{s}^{0}$ system, we estimate the lower bound on the mass of the ${Z}^{\ensuremath{'}}$ boson of models based on the $SU(3{)}_{c}\ensuremath{\bigotimes}SU(3{)}_{L}\ensuremath{\bigotimes}U(1{)}_{X}$ gauge group. By assuming zero-texture approaches of the quark mass matrices, we find the ratio of the measured value to the theoretical prediction from the standard model and the ${Z}^{\ensuremath{'}}$ contribution from the 331 models of the mass difference of the ${B}_{s}^{0}$ system. We find lower bounds on the ${Z}^{\ensuremath{'}}$ mass ranging between 1 TeV and 30 TeV for the two most popular 331 models, and four different zero-textures ans\"atze. The above results are expressed as a function of the weak angle associated to the $b\ensuremath{-}s\ensuremath{-}{Z}^{\ensuremath{'}}$ couplings.