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arXiv · 0912.0543

The f_{D_s} Puzzle

Andreas S. Kronfeld
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Abstract

Recent measurements of the branching fraction for D_s -> l nu disagree with the Standard Model by around 2sigma. In this case the key aspect of the Standard Model is the calculation of the decay constant, f_{D_s}, with lattice QCD. This talk surveys the experimental measurements, and explains how the lattice QCD calculations are done. Should the discrepancy strengthen again (it was earlier 3.8sigma), it would be a signal of new physics. Models that could explain such an effect are also discussed.

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Andreas S. Kronfeld. 2009-12-02. The f_{D_s} Puzzle. https://arxiv.org/abs/0912.0543

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