Neutral B mixing from 2+1 flavor lattice QCD

Abstract

We present an update of the Fermilab-MILC Collaboration's calculation of hadronic matrix elements for B^0-\bar{B^0} mixing. This work is a more extended analysis than our recent publication of the SU(3)-breaking ratio xi [arXiv:1205.7013]. We use the asqtad staggered action for light valence quarks in combination with the Fermilab interpretation of the Sheikoleslami-Wohlert action for heavy quarks. The calculations use MILC's 2+1 flavor asqtad ensembles. Ensembles include four lattice spacings from approximately 0.125 fm to 0.045 fm and up/down to strange quark mass ratios as low as 0.05. Our calculation covers the complete set of five operators needed to describe B mixing in the Standard Model and beyond. In addition to an update including a fuller set of analyzed data, we comment on the form of the staggered ChPT extrapolation function.

7 pages, 2 figures; Proceedings of the 30th International Symposium on Lattice Field Theory, June 24-29, 2012, Cairns, Australia

References in corpus (5)

• Anatomy of New Physics in B-Bbar mixing
• Neutral B Meson Mixing in Unquenched Lattice QCD
• Neutral B-meson mixing from three-flavor lattice QCD: Determination of the SU(3)-breaking ratio ξ
• Matrix elements of the complete set of ΔB = 2 and ΔC = 2 operators in heavy meson chiral perturbation theory
• Four Fermion Operator Matching with NRQCD Heavy and AsqTad Light Quarks