Measurement of D(s)- ---> tau- anti-tau-neutrino and a new limit for B- ---> tau- anti-tau-neutrino

Collaboration
Dec, 1996
18 pages
Published in:
  • Phys.Lett.B 396 (1997) 327-337
Report number:
  • CERN-PPE-96-198
Experiments:

Citations per year

1997200320092015202002468101214
Abstract: (Elsevier)
Using a data sample of 1 475 000 Z → qq̄(γ) events collected during 1994 with the L3 detector at LEP, we have studied the purely leptonic decays of heavy flavour mesons, D s − → τ − ν τ and B − → τ − ν τ . A signal is observed in the invariant mass distribution M(γD s − ) corresponding to the decay sequence D ∗− → γD s − , D s − → τ − ν τ , τ − → l − ν l ν τ . The branching fraction for D s − → τ − ν τ decays is measured to be β (D s − → τ − ν τ ) = 0.074 ± 0.028(stat) ± 0.016(syst) ± 0.018(norm) . No signal of B − → τ − ν τ decays is observed in the data, corresponding to an upper limit on the branching franction β( B − → τ − ν τ ) < 5.7 × 10 −4 at 90% CL.
  • electron positron: colliding beams
  • electron positron: annihilation
  • Z0: electroproduction
  • Z0: hadronic decay
  • D/s-: leptonic decay
  • B-: leptonic decay
  • D/s*(2110): radiative decay
  • mass spectrum: (D/s- photon)
  • D/s-: branching ratio
  • upper limit