First lattice calculation of the electromagnetic operator amplitude ⟨π0|Qγ+|K0⟩

We present the first lattice calculation of the matrix element of the electromagnetic operator [pi (0)/Q(gamma)(+)/K-0], where = Q(gamma)(+) = (Q(d)e/16 pi (2))((s) over bar (L)sigma (mu nu) F(mu nu)d(R) + (s) over bar (R)sigma (mu nu) F(mu nu)d(L)) This matrix element plays an important roe, since it contributes to enhance the CP violating part of the K-L --> pi (0)e(+)e(-) amplitude in supersymmetric extensions of the Standard Model. (C) 2001 Elsevier Science B.V. All rights reserved.