Standard model confronting new results for ε′/ε

We analyze the CP-violating ratio epsilon'/epsilon in the Standard Model in view of the new KTeV results. We review the present status of the most important non-perturbative parameters B-6((1/2)), B-8((3/2)), (B) over cap(K) and of the strange quark mass m(s). We also briefly discuss the issues of final state interactions and renormalization scheme dependence. Updating the values of the CKM parameters, of m(t) and Lambda (4)/MS and using Gaussian errors for the experimental input and flat distributions for the theoretical parameters we find epsilon'/epsilon substantially below the NA31 and KTeV data: epsilon'/epsilon = (7.7(-3.5)(+6.0)) X 10(-4) and epsilon'/epsilon = (5.2(-2.7)(+4.6)) X 10(-4) in the NDR and HV renormalization schemes respectively. A simple scanning of all input parameters gives on the other hand 1.05 X 10(-4) less than or equal to epsilon'/epsilon less than or equal to 28.8 X 10(-4) and 0.26 X 10(-4) less than or equal to epsilon'/epsilon less than or equal to 22.0 X 10(-4) respectively. Analyzing the dependence on various parameters we find that only for extreme values of B-6((1/2)), B-8((3/2)) and m(s) as well as suitable values of CKM parameters and Lambda(4)/MS, the ratio epsilon'/epsilon can be made consistent with data. We analyze the impact of these data on the lower bounds for Im VtdVts*, Br(K-L --> pi(0)nu<(nu)over bar>), Br(K-L --> pi(0)e(+)e(-))(dir) and on tan beta in the two-Higgs doubler Model II. (C) 2000 Elsevier Science B.V. All rights reserved.