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arXiv · 1306.2384

Rare decay B -> K ll form factors from lattice QCD

Chris Bouchard·G. Peter Lepage·Christopher Monahan·Heechang Na·Junko Shigemitsu
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Abstract

We calculate, for the first time using unquenched lattice QCD, form factors for the rare decay B -> Kll in and beyond the Standard Model. Our lattice QCD calculation utilizes a nonrelativistic QCD formulation for the b valence quarks, the highly improved staggered quark formulation for the light valence quarks, and employs the MILC 2+1 asqtad ensembles. The form factor results, based on the z expansion, are valid over the full kinematic range of q^2. We construct the ratios f0/f+ and fT/f+, which are useful in constraining new physics and verifying effective theory form factor symmetry relations. We also discuss the calculation of Standard Model observables.

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Chris Bouchard, G. Peter Lepage, Christopher Monahan, Heechang Na, Junko Shigemitsu. 2013-06-10. Rare decay B -> K ll form factors from lattice QCD. https://doi.org/10.1103/physrevd.88.054509

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