2004/06/01 by KTeV Collaboration, W. To, T. Alexopoulos +57 · 70 citations
Engineering · Mathematics · Physics and Astronomy · #Combinatorics #Mathematics #Neutrino Physics Research #Particle Accelerators and Free-Electron Lasers #Particle physics #Particle physics theoretical and experimental studies #Physics #hep-ex
paper · pdf · doi:10.1103/physrevd.70.092007
published in Physical review. D. Particles, fields, gravitation, and cosmology/Physical review. D. Particles and fields 70(9) (American Physical Society) · Submitted to Phys. Rev. D; 15 pages, 14 figures
arxiv created 2004/06/01 · openalex publication_date 2004/11/16 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We present new measurements of KL semileptonic form factors using data collected in 1997 by the KTeV (E832) experiment at Fermilab. The measurements are based on 1.9\ifmmode×\else\texttimes\fi106 KL\ensuremath→\ensuremathπ^\ifmmode±\else\textpm\fie^\ensuremath∓\ensuremathν and 1.5\ifmmode×\else\texttimes\fi106 KL\ensuremath→\ensuremathπ^\ifmmode±\else\textpm\fi\ensuremathμ^\ensuremath∓\ensuremathν decays. For f+(t), we measure both a linear and quadratic term: \ensuremathλ+^\ensuremath'=(20.64\ifmmode±\else\textpm\fi1.75)\ifmmode×\else\texttimes\fi10^\ensuremath-3 and \ensuremathλ+^\ensuremath'\ensuremath'=(3.20\ifmmode±\else\textpm\fi0.69)\ifmmode×\else\texttimes\fi10^\ensuremath-3. For f0(t), we find \ensuremathλ0=(13.72\ifmmode±\else\textpm\fi1.31)\ifmmode×\else\texttimes\fi10^\ensuremath-3. These form factors are consistent with K^\ifmmode±\else\textpm\fi form factors, suggesting that isospin symmetry breaking effects are small. We use our measured values of the form factors to evaluate the decay phase space integrals, IKe=0.15350\ifmmode±\else\textpm\fi0.00105 and IK^\ensuremathμ=0.10165\ifmmode±\else\textpm\fi0.00080, where errors include uncertainties arising from the form factor parametrizations.