Elusive ''penguin'' mechanism for K decay

We observe that the uncertainty in estimating the ''penguin'' diagram is so large that its contribution to A(K→2π) can range from 30% to negligible, and thus no meaningful lower bound can be set for epsilon'/epsilon. We then map out the relations between the experimental measurements of epsilon'/epsilon and m/sub t/ and the hadronic dynamical parameters for use in the search for the ''penguin.''