We present the results of our recent calculation of $\epsilon^{ \prime}/ \epsilon$ at the Next-to-Leading (NLO) order in QCD and QED, in the framework of $\DSone$ Effective Hamiltonians. The operator matrix elements are taken from lattice QCD, at a scale $\mu=2\,\,\mbox{ GeV}$. NLO corrections seem to lower the value of $\epsilon^{ \prime}/\epsilon$, favouring the experimental result of E731. Contributions from different operators are analyzed and dependence on $\mt$, $\mu$ and $\Lambda_{ \sss QCD}$ discussed. (Talk given at the XXVIIIth Rencontres de Moriond, ``Electro-Weak Interactions and Unified Theories'', March 13-19 1993).
Categories: hep-ph