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arXiv · 0811.1590

A Mixed Tau-Electroproduction Sum Rule for V_us

Kim Maltman
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Abstract

The interpretation of results of recent tau decay determinations of |V_us|, which yield values ~3 sigma low compared to 3-family unitarity expectations, is complicated by the slow convergence of the relevant integrated D=2 OPE series. We introduce a class of sum rules involving both electroproduction and tau decay data designed to deal with this problem by strongly suppressing D=2 OPE contributions at the correlator level. Experimental complications are briefly discussed and an example of the improved control over theoretical errors presented. The uncertainty on the resulting determination, |V_{us}| =0.2202(39), is entirely dominated by experimental errors, and should be subject to significant near-term improvement.

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Kim Maltman. 2009-06-07. A Mixed Tau-Electroproduction Sum Rule for V_us. https://doi.org/10.1016/j.physletb.2009.01.036

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