1999/07/22 by R. Appel, G. S. Atoyan, B. Bassalleck +34 · 4 citations
Chemistry · Mathematics · Physics and Astronomy · #Atomic physics #Branching fraction #Chemistry #Combinatorics #Context (archaeology) #Crystallography #High-Energy Particle Collisions Research #Mathematics #Particle physics #Particle physics theoretical and experimental studies #Physics #Quantum Chromodynamics and Particle Interactions #hep-ex
paper · pdf · doi:10.1103/physrevlett.83.4482
published as Phys.Rev.Lett.83:4482-4485,1999 · 4 pages, 5 figures
arxiv created 1999/07/22 · openalex publication_date 1999/11/29 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
A low-background sample of 10 300 events has been collected for the decay mode K+\ensuremath→\ensuremathπ+e+e^\ensuremath- by experiment E865 at the Brookhaven Alternating Gradient Synchrotron. The branching ratio is measured to be [2.94\ifmmode±\else\textpm\fi0.05(stat)\ifmmode±\else\textpm\fi0.13(syst)\ifmmode±\else\textpm\fi0.05(model)]\ifmmode×\else\texttimes\fi10^\ensuremath-7, the vector nature of this decay is firmly established, and the decay form factor f(z)\phantom\rule0ex0ex=\phantom\rule0ex0exf0(1+\ensuremathδz)(z\phantom\rule0ex0ex=\phantom\rule0ex0exMee2/mK2) is determined to have \ensuremathδ\phantom\rule0ex0ex=\phantom\rule0ex0ex2.14\ifmmode±\else\textpm\fi0.13\ifmmode±\else\textpm\fi0.15. The experiment is described and results discussed in the context of chiral perturbation theory.