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arXiv · 0712.3841

Measurement of the absolute branching ratios for semileptonic K+/- decays with the KLOE detector

KLOE Collaboration
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Abstract

Using a sample of over 600 million phi->K+K- decays collected at the Dafne e+e- collider, we have measured with the KLOE detector the absolute branching ratios for the charged kaon semileptonic decays, K+/- -> p0 e nu (gamma) (Ke3) and K+/- -> p0 mu nu (gamma) (Kmu3). The results, BR(Ke3) = 0.04965 +/- 0.00038_{stat} +/- 0.00037_{syst} and BR(Kmu3) = 0.03233 +/- 0.00029_{stat} +/- 0.00026_{syst}, are inclusive of radiation. Accounting for correlations, we derive the ratio Kmu3/Ke3 = 0.6511+/-0.0064. Using the semileptonic form factors measured in the same experiment, we obtain V_{us}f_{+}(0) = 0.2141 +/- 0.0013.

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KLOE Collaboration. 2008-02-28. Measurement of the absolute branching ratios for semileptonic K+/- decays with the KLOE detector. https://doi.org/10.1088/1126-6708%2F2008%2F02%2F098

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