  We present preliminary results of a non-perturbative study of the
scale-dependent renormalization constants of a complete basis of Delta F=2
parity-odd four-fermion operators that enter the computation of hadronic
B-parameters within the Standard Model (SM) and beyond. We consider
non-perturbatively O(a) improved Wilson fermions and our gauge configurations
contain two flavors of massless sea quarks. The mixing pattern of these
operators is the same as for a regularization that preserves chiral symmetry,
in particular there is a "physical" mixing between some of the operators. The
renormalization group running matrix is computed in the continuum limit for a
family of Schrodinger Functional (SF) schemes through finite volume recursive
techniques. We compute non-perturbatively the relation between the
renormalization group invariant operators and their counterparts renormalized
in the SF at a low energy scale, together with the non-perturbative matching
matrix between the lattice regularized theory and the various SF schemes.
