Preliminary results for exclusive b --> u l nu decays from CLEO.

Gibbons, Lawrence ;
(1995) 125-132, 1995.
Inspire Record 397218 DOI 10.17182/hepdata.47265

A preliminary analysis of exclusive $\btou$ decays to the final states $\pi~\pm\ell\nu$, $\pi~0\ell\nu$, $\rho~\pm\ell\nu$, $\rho~0\ell\nu$\ and $\omega\ell\nu$ based on $2.2\e{6}$ $\bbar$ decays collected at CLEO is presented. We have measured the first exclusive $\btou$ branching fraction $\bbpi=[1.19\pm0.41\pm0.21\pm0.19]\e{-4}$ ($[1.70\pm0.51\pm0.31\pm0.27]\e{-4}$), with the ISGW (WSB) model used for efficiency determination. A 90\% C.L. upper limit on $\bbrho$ similar to the previous CLEO limit is obtained. The ratio $\gamrho/\gampi<3.4$ at the 90\% confidence level for both the ISGW and WSB models. This ratio provides some discrimination between form factor models.

3 data tables

The statistical and systematic uncertainties have been combined in quadrature.. 90% CL.

Both ISGW and WSB models, 90% CL. The statistical and systematic uncertainties have been combined in quadrature.