# Poster presented by Thomas Blum

Poster Session

Topic: Matrix Elements

### $\epsilon^prime/epsilon$ from the lattice

Abstract: We calculate the matrix elements of the $\Delta S=1$ effective weak hamiltonian needed for the Standard Model prediction of the direct $CP$ violation parameter $\epsilon^\prime$. We use domain wall quarks on quenched lattices at $6/g^2=6.0$ and 5.85. The operators of the weak hamiltonian are renormalized nonperturbatively using the Rome method.

Massimo Campostrini,   campo@mailbox.difi.unipi.it