  We report on a calculation of $\epsilon_K'/\epsilon_K$ at next-to-leading in
the $1/N_c$ expansion and to lowest order in Chiral Perturbation Theory. We
discuss the short-distance matching, the scale and scheme dependence as well as
the long-distance short-distance matching. We include the two known chiral
corrections to our result and discuss further order $p^4$ corrections to it.

High Energy Physics - Phenomenology