Measurements of the branching fraction and decay distributions for K L → π± μ νγ and KL → π± e∓ νγ

T. Alexopoulos, T. Andre, 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. HammK. Hanagaki, Y. 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, 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

20 Scopus citations


We present measurements of ℛℓ3γ ≡ Γ(K L±ℓ∓ νγ E γ* > 10 MeV)/Γ(KL →± ℓ∓ν), where ℓ = μ or e, and E γ* is the photon energy in the kaon rest frame. These measurements are based on KL decays collected in 1997 by the KTeV (E832) experiment at Fermilab. With samples of 1385 KL → π± μ νγ and 14221 KL → π± e νγ candidates, we find ℛKμ3γ = (0.530 ± 0.019)% and ℛKe3γ = (4.942 ± 0.062)%. We also examine distributions of photon energy and lepton-photon angle.

Original languageEnglish (US)
Article number012001
Pages (from-to)012001-1-012001-12
JournalPhysical Review D - Particles, Fields, Gravitation and Cosmology
Issue number1
StatePublished - Jan 2005

ASJC Scopus subject areas

  • Nuclear and High Energy Physics
  • Physics and Astronomy (miscellaneous)


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