文章基本信息

标题：Theoretical progress on the Vus determination from tau decays
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作者：A. Pich
期刊名称：PoS - Proceedings of Science
印刷版ISSN：1824-8039
出版年度：2007
出版社：SISSA, Scuola Internazionale Superiore di Studi Avanzati
摘要：A very precise determination of Vus can be obtained from the semi-inclusive hadronic decay width of the t lepton into final states with strangeness. The ratio of the Cabibbo-suppressed and Cabibbo-allowed t decay widths directly measures (Vus=Vud)2, up to very small SU(3)-breaking corrections which can be theoretically estimated with the needed accuracy. Together with previous LEP and CLEO data, the recent measurements by Babar and Belle of some Cabibbo-suppressed t decays imply Vus = 0:21650:0026exp0:0005th, which is already competitive with the standard extraction from Kl3 decays. The uncertainty is largely dominated by experimental errors and should be easily reduced with the high statistics of the B factories, providing the most accurate determination of this parameter. A 1% experimental precision on the Cabibbo-suppressed t decay width would translate into a 0.6% uncertainty on Vus.