2007/02/28 by J. R. Batley, NA48/2 collaboration, C. Lazzeroni +98 · 2 citations
Physics and Astronomy · #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-ex
paper · pdf · doi:10.1140/epjc/s10052-007-0253-3
published as Eur.Phys.J.C50:329-340,2007; Erratum-ibid.C52:1021-1023,2007 · 20 pages, 5 tables, 10 figures. Published in European Physical Journal C 50 2 (2007), contains erratum submitted to European Physical Journal C
openalex publication_date 2007/03/13 · arxiv created 2007/05/21 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/04
Measured ratios of decay rates for Ke3/K2π, Kμ3/K2πand Kμ3/Ke3 are presented. These measurements are based on K+- decays collected in a dedicated run in 2003 by the NA48/2 experiment at CERN. The results obtained are Ke3/K2π= 0.2470 +/- 0.0009 (stat) +/- 0.0004 (syst) and Kμ3/K2π= 0.1637 +/- 0.0006 (stat) +/- 0.0003 (syst). Using the PDG average for the K+- -> π+-π0 normalisation mode, both values are found to be larger than the current values given by the Particle Data Book and lead to a larger magnitude of the |Vus| CKM element than previously accepted. When combined with the latest Particle Data Book value of |Vud|, the result is in agreement with unitarity of the CKM matrix. In addition, a new measured value of Kμ3/Ke3 = 0.663 +/- 0.003(stat) +/- 0.001(syst) is compared to the semi-empirical predictions based on the latest form factor measurements.