Precision measurement of B(D+→μ+ν) and the pseudoscalar decay constant fD+

B. I. Eisenstein, I. Karliner, S. Mehrabyan, N. Lowrey, M. Selen, E. J. White, J. Wiss, R. E. Mitchell, M. R. Shepherd, D. Besson, T. K. Pedlar, D. Cronin-Hennessy, K. Y. Gao, J. Hietala, Y. Kubota, T. Klein, B. W. Lang, R. Poling, A. W. Scott, P. ZweberS. Dobbs, Z. Metreveli, K. K. Seth, A. Tomaradze, J. Libby, L. Martin, A. Powell, G. Wilkinson, K. M. Ecklund, W. Love, V. Savinov, H. Mendez, J. Y. Ge, D. H. Miller, I. P.J. Shipsey, B. Xin, G. S. Adams, M. Anderson, J. P. Cummings, I. Danko, D. Hu, B. Moziak, J. Napolitano, Q. He, J. Insler, H. Muramatsu, C. S. Park, E. H. Thorndike, F. Yang, M. Artuso, S. Blusk, S. Khalil, J. Li, N. Menaa, R. Mountain, S. Nisar, K. Randrianarivony, N. Sultana, T. Skwarnicki, S. Stone, J. C. Wang, L. M. Zhang, G. Bonvicini, D. Cinabro, M. Dubrovin, A. Lincoln, P. Naik, J. Rademacker, D. M. Asner, K. W. Edwards, J. Reed, R. A. Briere, T. Ferguson, G. Tatishvili, H. Vogel, M. E. Watkins, J. L. Rosner, J. P. Alexander, D. G. Cassel, J. E. Duboscq, R. Ehrlich, L. Fields, R. S. Galik, L. Gibbons, R. Gray, S. W. Gray, D. L. Hartill, B. K. Heltsley, D. Hertz, J. M. Hunt, J. Kandaswamy, D. L. Kreinick, V. E. Kuznetsov, J. Ledoux, H. Mahlke-Krüger, D. Mohapatra, P. U.E. Onyisi, J. R. Patterson, D. Peterson, D. Riley, A. Ryd, A. J. Sadoff, X. Shi, S. Stroiney, W. M. Sun, T. Wilksen, S. B. Athar, R. Patel, J. Yelton, P. Rubin

Research output: Contribution to journalArticle


We measure the branching ratio of the purely leptonic decay of the D+ meson with unprecedented precision as B(D+→μ+ν)=(3.82±0. 32±0.09)×10-4, using 818pb-1 of data taken on the ψ(3770) resonance with the CLEO-c detector at the CESR collider. We use this determination to derive a value for the pseudoscalar decay constant fD+, combining with measurements of the D+ lifetime and assuming |Vcd|=|Vus|. We find fD+=(205.8±8.5±2.5)MeV. The decay rate asymmetry Γ(D+→μ+ν)-Γ(D-→μ-ν̄)Γ(D+→μ +ν)+Γ(D-→μ-ν̄)=0.08±0.08, consistent with no CP violation. We also set 90% confidence level upper limits on B(D+→τ+ν )<1.2×10-3 and B(D+→e+ν)<8.8×10-6.

Original languageEnglish (US)
Article number052003
JournalPhysical Review D - Particles, Fields, Gravitation and Cosmology
Issue number5
StatePublished - Sep 11 2008


ASJC Scopus subject areas

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

Cite this

Eisenstein, B. I., Karliner, I., Mehrabyan, S., Lowrey, N., Selen, M., White, E. J., Wiss, J., Mitchell, R. E., Shepherd, M. R., Besson, D., Pedlar, T. K., Cronin-Hennessy, D., Gao, K. Y., Hietala, J., Kubota, Y., Klein, T., Lang, B. W., Poling, R., Scott, A. W., ... Rubin, P. (2008). Precision measurement of B(D+→μ+ν) and the pseudoscalar decay constant fD+. Physical Review D - Particles, Fields, Gravitation and Cosmology, 78(5), [052003].