New four-quarkΔS=2local operator

Abstract
We describe a new four-quark ΔS=2 local operator, which we dub the ‘‘dipenguin’’ operator. Its form is derived and its K¯ 0-to-K0 matrix element is estimated. Also, we comment upon bag-model evaluations of K¯ 0-to-K0 matrix elements of (V-A)×(V-A) operators.