arXiv subjects
Publications and source records attributed to Lawrence Gibbons.
I survey the theoretical and experimental information available for determination of |Vub| with inclusive and exclusive techniques. Using recent experimental and theoretical advances, I outline a procedure in which the inclusive information can be combined to obtain an inclusive |Vub| that includes experimentally--derived uncertainty estimates for outstanding theoretical corrections.
I present a brief overview of the measurements of exclusive B -> X_u l nu transitions, with a focus on issues facing robust averaging of branching fractions and |Vub| from current and anticipated measurements.
A preliminary analysis of exclusive $\btou$ decays to the final states $π^\pm\ellν$, $π^0\ellν$, $ρ^\pm\ellν$, $ρ^0\ellν$\ and $ω\ellν$ 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.