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arXiv · 1212.5470

Neutral B mixing from 2+1 flavor lattice QCD

E. D. Freeland·C. M. Bouchard·C. Bernard·A. X. El-Khadra·E. Gamiz·A. S. Kronfeld·J. Laiho·R. S. Van de Water
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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.

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E. D. Freeland, C. M. Bouchard, C. Bernard, A. X. El-Khadra, E. Gamiz, A. S. Kronfeld, J. Laiho, R. S. Van de Water. 2012-12-21. Neutral B mixing from 2+1 flavor lattice QCD. https://arxiv.org/abs/1212.5470

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