Determination of BK using improved staggered fermions (I): SU(3) chiral perturbation theory fit
Abstract
We present the results for BK calculated using HYP-smeared staggered fermions using lattices generated by the MILC collaboration using the asqtad staggered action. We have done the calculation on 8 ensembles of these lattices, including three different lattice spacings (a=0.12, 0.09, 0.06 fm). We fit the data to forms based on those predicted by SU(3) mixed-action partially-quenched staggered chiral perturbation theory. Our preliminary result is BK(NDR,μ=2GeV) = 0.528 0.011 0.048 , where the first error is statistical and the second systematic. The error turns out to be larger than that from an analysis using SU(2) chiral perturbation theory.
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