Measurements of semileptonic KL decay form factors

T. Alexopoulos, M. Arenton, R. F. Barbosa, A. R. Barker, L. Bellantoni, A. Bellavance, E. Blucher, G. J. Bock, E. Cheu, S. Childress, R. Coleman, M. D. Corcoran, B. Cox, A. R. Erwin, R. Ford, A. Glazov, A. Golossanov, J. Graham, J. Hamm, K. HanagakiY. B. Hsiung, H. Huang, V. Jejer, D. A. Jensen, R. Kessler, H. G E Kobrak, K. Kotera, J. LaDue, A. Ledovskoy, P. L. McBride, E. Monnier, K. S. Nelson, H. Nguyen, R. Niclasen, V. Prasad, X. R. Qi, E. J. Ramberg, R. E. Ray, M. Ronquest, E. Santos, P. Shanahan, J. Shields, W. Slater, D. Smith, N. Solomey, E. C. Swallow, R. J. Tesarek, P. A. Toale, R. Tschirhart, Y. W. Wah, J. Wang, H. B. White, J. Whitmore, M. Wilking, B. Winstein, R. Winston, E. T. Worcester, T. Yamanaka, E. D. Zimmerman

    Research output: Contribution to journalArticlepeer-review


    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 × 106 KL → π±e∓ν and 1.5 × 106 KL → π±μ∓ν decays. For f+(t), we measure both a linear and quadratic term: λ′+ = (20.64 ± 1.75) × 10-3 and λ″+ = (3.20 ± 0.69) × 10-3. For f0(t), we find λ0 = (13.72 ± 1.31) × 10-3. These form factors are consistent with K± 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 ± 0.00105 and I Kμ = 0.10165 ± 0.00080, where errors include uncertainties arising from the form factor parametrizations.
    Original languageEnglish
    Article number092007
    Pages (from-to)1-92007
    Number of pages92006
    JournalPhysical Review D - Particles, Fields, Gravitation and Cosmology
    Issue number9
    Publication statusPublished - Nov 2004


    Dive into the research topics of 'Measurements of semileptonic KL decay form factors'. Together they form a unique fingerprint.

    Cite this