Effects of Quenching and Partial Quenching on QCD Penguin Matrix Elements

Abstract

We point out that chiral transformation properties of penguin operators change in the transition from unquenched to (partially) quenched QCD. The way in which this affects the lattice determination of weak matrix elements can be understood in the framework of (partially) quenched chiral perturbation theory.

Comments: 3 pages, Lattice2001(matrixelement), minor corrections