On the Nf and a Dependence of BK
  We present results of a study of BK using tadpole improved gauge invariant staggered operators. Using three ensembles of 16^3x32 configurations with varying numbers of dynamical flavors, we observe a small dependence on Nf. Using seven quenched ensembles between beta=5.7 and beta=6.2 we extrapolate to a=0. 
G. Kilcup, D. Pekurovsky and L. Venkataraman