Quenching effects in strong penguin contributions to ${ϵ}^{\prime }/ϵ$

Abstract

Quenching effects in strong penguin matrix elements are investigated. A lattice determination of ${\alpha }_q^{NS}$, the constant that appears in the quenched ChPT relevant for the lattice analysis of $K\to \pi \pi$ matrix elements, shows that this constant is large. The original RBC analysis of $Q_6$ matrix elements is revisited in light of this result. Also, the numerical effects of choosing the singlet Golterman-Pallante method of quenching $Q_6$ is investigated.

Comments: 3 pages, talk presented at Lattice2004(weak), Fermilab, June 21-26, 2004