Analysis of the mixing matrix in a model with coincident quark electroweak and mass eigenstates

A new approach to relating quark masses and mixing angles was proposed by del Águila, Kane, and Quirós, in which the mass matrix for the weak eigenstates was assumed to be diagonal in the absence of mixing with heavier quarks. The purpose of this paper is to examine in detail the constraints of CP violation and $B^0$-B¯ ${}_{}{}^0{}_{}{}^{}$ mixing on the quark-mixing-angle matrix of the model and the range of $m_t$ for which the description could hold. For the case where CP violation and $B^0$-B¯ ${}_{}{}^0{}_{}{}^{}$ mixing arise from the quark mixing matrix the result is that, for at least some values of the parameters, $m_t$ can be as small as 85 GeV but not less. In addition, ‖$V_{\mathrm{ub}}$‖/‖$V_{\mathrm{cb}}$‖ is required to be larger than 0.11, an important constraint on the model. Mixing and CP violation arising from flavor-changing currents present in the model are also examined.