The ratio Phi -> K+K-/K-0(K)over-bar(0)

The ratio Phi --> K+K-/K-0(K) over bar(0) is discussed and its present expe rimental value is compared with theoretical expectations. A difference larg er than two standard deviations is observed. We critically examine a number of mechanisms that could account for this discrepancy, which remains unexp lained. Measurements at DA Phi NE at the level of the per mille accuracy ca n clarify whether there exist any anomaly. (C) 2000 Published by Elsevier S cience B.V.