The 2004 UTfit collaboration report on the status of the unitarity triangle in the standard model

Using the latest determinations of several theoretical and experimental pa- rameters, we update the Unitarity Triangle analysis in the Standard Model. The basic experimental constraints come from the measurements of |Vub/Vcb|, ∆md, the lower limit on ∆ms, εK, and the measurement of the phase of the Bd–Bd mixing amplitude through the time-dependent CP asymmetry in B0 → J/ψK0 decays. In addition, we consider the direct determination of α, γ, 2β+γ and cos2β from the measurements of new CP-violating quantities, recently performed at the B factories. We also discuss the opportunities offered by improving the precision of the various physical quantities entering in the determination of the Unitarity Triangle parameters. The results and the plots presented in this paper can also be found at the URL http://www.utfit.org, where they are continuously updated with the newest experimental and theoretical results.