A review of the current status of the Cabibbo-Kobayashi-Maskawa matrix V_CKM
is presented. This paper contains an update of the results published in
hep-ph/9711261. Values of the parameters entering into the constraints, which
restrict the range for rho and eta parameters, include recent measurements
given at 1997 Summer Conferences and progress obtained by lattice QCD
collaborations.Experimental constraints imposed by the measurements of
epsilon_k,V_ub/V_cb, Delta m_d and by the limit on Delta m_s, are compatible
and do not show evidence for New Physics inside measurements errors. Values for
the angles alpha, beta and gamma of the C.K.M. triangle have been also
obtained: rho=0.156 +- 0.090, eta=0.328 +- 0.054 sin 2alpha = -0.10+-0.40, sin
2beta = 0.68 +- 0.10, gamma= 64+-12 Angles theta,theta_u,theta_d and phi
proposed in the parametrisation (Phys. Lett. B5353 (1995) 114.) of the C.K.M.
matrix have been also determined. Finally, as there are more constraints than
the fitted rho and eta parameters, several external measurements or theoretical
inputs have been removed, in turn, from the constraints and their respective
values have been fitted simultaneously with rho and eta.Central values and
uncertainties on these quantities have been compared with actual measurements
or theoretical evaluations. In this way it is possible to quantify the
importance of the different measurements and the coherence of the Standard
Model scenario for CP violation.Comment: 29 page