Published February 1989 | Version v1
Journal article

The electron spectrum from B meson decays

  • 1. Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany, F.R.)
  • 2. Harvard Univ., Cambridge, MA (USA)
  • 3. Hamburg Univ. (Germany, F.R.). 1. Inst. fuer Experimentalphysik
  • 4. Florence Univ. (Italy)
  • 5. Istituto Nazionale di Fisica Nucleare, Florence (Italy)
  • 6. Stanford Linear Accelerator Center, CA (USA)
  • 7. Stanford Univ., CA (USA). High-Energy Physics Lab.
  • 8. Stanford Univ., CA (USA). Dept. of Physics
  • 9. California Univ., Santa Cruz (USA)
  • 10. Erlangen-Nuernberg Univ., Erlangen (Germany, F.R.)
  • 11. Wuerzburg Univ. (Germany, F.R.)
  • 12. Institute of Nuclear Physics, Krakow (Poland)
  • 13. Nationaal Inst. voor Kernfysica en Hoge-Energiefysica (NIKHEF), Nijmegen (Netherlands)
  • 14. Katholieke Univ. Nijmegen (Netherlands)
  • 15. California Inst. of Tech., Pasadena (USA)

Description

The Crystal Ball Collaboration has measured the energy spectrum of electrons from semileptonic B meson decays at the e+e- storage ring DORIS II. Branching ratios and weak mixing angles of the Kobaysashi-Maskawa matrix are determined using several models for the hadronic matrix elements. We obtain the branching ratio for semileptonic B decays to charmed states BR(B → eνXc) = (11.7 ± 0.4 ± 1.0)%. Our result for the corresponding Kobaysashi-Maskawa matrix element is vertical strokeVcbvertical stroke = 0.052 ± 0.006. The model dependence of both results is included in the error. We have not observed semileptonic B decays to non-charmed mesons. Analyzing the measured electron spectrum above 2.4 GeV, where no b → c decays contribute, we find BR(B → eνXu)/BR (B → eνXc) < 6.5% at the 90% confidence level. This corresponds to an upper limit vertical strokeVub/Vcbvertical stroke < 0.21. (orig.)

Additional details

Publishing Information

Journal Title
Zeitschrift fuer Physik, C
Journal Volume
42
Journal Issue
1
Series
Z. Phys., C.
Journal Page Range
33-48
ISSN
0170-9739
CODEN
ZPCFD