A novel route to V_us
Abstract
Description
Already in the past, hadronic tau decays have served as an interesting source to obtain information on the parameters of the Standard Model, like the strong coupling alpha_s or the strange quark mass. Below it will be shown that the approach to obtain the strange mass from the hadronic tau-decay width can be turned into a determination of the CKM matrix element V_us, once the strange mass is used as an input from other sources. At present, we obtain V_us = 0.2179 +- 0.0045, where the error is completely dominated by the experimental uncertainty, and can be improved through an improved measurement of the hadronic tau-decay rate into strange particles R_tau,S.
4 pages, 1 figure, contribution to CKM03, Durham, April 2003
4 pages, 1 figure, contribution to CKM03, Durham, April 2003