ar X iv : h ep - l at / 0 20 91 41 v 1 1 9 Se p 20 02 Gasser – Leutwyler coefficients : A progress report

Last year, we reported our first results on the determination of Gasser–Leutwyler coefficients using partially quenched lattice QCD with three flavors of dynamical staggered quarks. We give an update on our progress in determining two of these coefficients, including an exhaustive effort to estimate all sources of systematic error. At this conference, we have heard about algorithmic techniques to reduce staggered flavor symmetry breaking and a method to incorporate staggered flavor breaking into the partially quenched chiral Lagrangian. We comment on our plans to integrate these developments into our ongoing program.