0000000000659820
AUTHOR
Vangemmeren P
A study of tau decays involving eta and omega mesons
The 132 pb(-1) of data collected by ALEPH from 1991 to 1994 have been used to analyze eta and omega production in 7 decays. The following branching fractions have been measured: B(tau(-) --> nu(tau)omega h(-)) = (1.91 +/- 0.07 +/- 0.06) x 10(-2), B(tau(-) --> nu(tau)omega h(-)pi(0)) = (4.3 +/- 0.6 +/- 0.5) x 10(-3), B(tau(-) --> nu(tau)eta K-) = (2.9(-1.2)(+1.3) +/- 0.7) x 10(-4), B(tau(-) --> nu(tau)eta(h)(-)pi(0)) = (1.8 +/- 0.4 +/- 0.2) x 10(-3) and the 95% C.L. limit B(tau(-) --> nu(tau)eta pi(-)) < 6.2 x 10(-4) has been obtained. The omega pi(-) and eta pi(-)pi(0) rates and dynamics are found in agreement with the predictions made from e(+)e(-) annihilation data with the help of isospi…
Measurement of the Effective b quark Fragmentation Function At the Z resonance
Using a sample of about 1.46 million hadronic Z decays collected between 1991 and 1993 with the ALEPH detector at LEP, the energy distribution of the B-0 and B-+/- mesons produced at the Z resonance is measured by reconstructing semileptonic decays B --> l nu(l)D(X) or B --> l nu(l)D*(+)(X). The charmed mesons are reconstructed through the decay modes D-0 --> K(-)pi(+), D-0, --> K(-)pi(+)pi(-)pi(+),D+ --> K(-)pi(+)pi(+), and D*(+) --> D-0 pi(+). The neutrino energy is estimated from the missing energy in the lepton hemisphere. Accounting for B* and B** production, the shape of the scaled energy distribution x(E)((b)) for mesons containing a b quark is compared to the predictions of differen…