The CKM matrix and the unitarity triangle: another look

The unitarity triangle can be determined by means of two measurements of its sides or angles. Assuming the same relative errors on the angles (fi;fl;∞) and the sides (Rb;Rt), we flnd that the pairs (∞;fl) and (∞;Rb) are most e-cient in determining (" " ·) that describe the apex of the unitarity triangle. They are followed by (fi;fl), (fi;Rb), (Rt;fl), (Rt;Rb) and (Rb;fl). As the set jVusj, jVcbj, Rt and fl appears to be the best candidate for the fundamental set of ∞avour violating parameters in the coming years, we show various constraints on the CKM matrix in the (Rt;fl) plane. Using the best available input we determine the universal unitarity triangle for models with minimal ∞avour violation (MFV) and compare it with the one in the Standard Model. We present allowed ranges for sin2fl, sin2fi, ∞, Rb, Rt and ¢Ms within the Standard Model and MFV models. We also update the allowed range for the function Ftt that parametrizes various MFV-models.