Determination of V_us: recent progresses from theory
Abstract
Description
Recent experimental and theoretical results on kaon semileptonic decays have significantly improved the determination of the CKM matrix element V_us. After briefly summarizing the impact of the new experimental determinations, I will concentrate in this talk on the theoretical progresses, coming in particular from lattice QCD calculations. These results lead to the estimate |V_us|=0.2250 +- 0.0021, in good agreement with the expectation based on the determination of |V_ud| and the unitarity of the CKM matrix.
Prepared for 17th Les Rencontres de Physique de la Vallee d'Aoste: Results and Perspectives in Particle Physics, La Thuile, Italy, February 27-March 5, 2005
Prepared for 17th Les Rencontres de Physique de la Vallee d'Aoste: Results and Perspectives in Particle Physics, La Thuile, Italy, February 27-March 5, 2005