B-parameters for Delta S=2 supersymmetric operators

We present a calculation of the matrix elements of the most general set of Delta S = 2 dimension-six four-fermion operators. The values of the matrix elements are given in terms of the corresponding B-parameters. Out results can be used in many phenomenological applications, since the operators cons idered here give important contributions to K-0-(K) over bar(0) mixing in s everal extensions of the Standard Model (supersymmetry, left-right symmetri c models, multi-Higgs models etc.). The determination of the matrix element s improves the accuracy of the phenomenological analyses intended to put bo unds on basic parameters of the different models, as for example the patter n of the sfermion mass matrices. The calculation has been pet-formed on the lattice, using the tree-level improved Clover action at two different valu es of the strong coupling constant (beta = 6/g(0)(2)(a)= 6.0 and 6.2, corre sponding to a(-1) = 2.1 and 2.7 GeV respectively), in the quenched approxim ation. The renormalization constants and mixing coefficients of the lattice operators have been obtained non-perturbatively. (C) 1999 Published by Els evier Science B.V. All rights reserved.