Fritzsch-Xing mass matrices,Vtd,and theCP-violating phase δ

Natural four zeros texture mass matrices recently proposed by Fritzsch and Xing are investigated by including “nonleading” corrections in the context of the latest data regarding $m_t^{\mathrm{pole}}$ and $V_{\mathrm{CKM}}$ matrix elements. Apart from accommodating $m_t^{\mathrm{pole}}$ in the range $175\pm 15\mathrm{GeV},$ $|V_{\mathrm{cb}}|$ and $|V_{\mathrm{ub}}{/V}_{\mathrm{cb}}|=0.08\mathrm{}\pm 0.02,$ the analysis with maximal $\mathrm{CP}$ violation predicts $|V_{\mathrm{td}}|=0.005\mathrm{}–\mathrm{0.013.}$ Further, the $\mathrm{CP}$-violating phase angle δ can be restricted to the ranges (i) 22°–45° and (ii) 95°–130°, concretizing the ambiguity regarding the phase of the CKM matrix. Furthermore, we find that nonleading calculations are important when the “Cabibbo triangle” is to be linked to the unitarity triangle.