Recent progress in calculation of $B_K$ using staggered fermions

Abstract

We report on recent progress in the calculation of $B_K$ using HYP-smeared improved staggered fermions on the MILC asqtad lattices. We have added measurements on fine ($a\sim 0.09$fm) and superfine ($a\sim 0.06$fm) ensembles at different values of the light sea quark mass ($a{m}_{\ell }$), as well as increased the statistics on some other ensembles. We find that the results on the fine lattices show a significantly stronger $a{m}_{\ell }$ dependence than those on the superfine and coarse ($a\sim 0.12$fm) lattices. We discuss different methods for accounting for these new results when doing the $a{m}_{\ell }$ and continuum extrapolations.

7 pages, 6 figures

References in corpus (5)

• Review of lattice results concerning low energy particle physics
• Possible evidence for the breakdown of the CKM-paradigm of CP-violation
• $B_K$ using HYP-smeared staggered fermions in $N_f=2+1$ unquenched QCD
• Finite volume effects in $B_K$ with improved staggered fermions
• Covariance fitting of highly correlated data in lattice QCD