Miscellanies of $ K^0 - \bar{K}^0 $ mixing and $ B_K $
  We have computed $ B_K $, using two different methods with staggered fermions on a $ 16^3 \times 40 $ lattice at $ \beta = 5.7 $ with two dynamical flavors of a mass 0.01. % Using an improved wall source method, we have studied a series of non-degenerate quark antiquark pairs and observed no effect on $ B_K $, although effects were seen on the individual terms making up $ B_K $. 
Markus Klomfass and Weonjong Lee