Finite Volume Errors in $B_K$
  We discuss finite volume errors in our calculations of $B_K$ using improved staggered fermions on the MILC asqtad lattices. Using GPUs, we are now able to extrapolate using next-to-leading order (NLO) staggered SU(2) chiral perturbation theory including the finite volume corrections arising from pion loops. We find that the impact of FV fitting is very small, giving a 0.5% shift in the continuum limit. 
Jangho Kim, Hyung-Jin Kim, Weonjong Lee, Chulwoo Jung, Stephen R.   Sharpe
hep-lat