We report the first evidence of charmless semileptonic decays of B mesons. In the momentum interval 2.42.6 GeV/c where the background from bcl is negligible, the average of the measured ue and u partial branching ratios is Bub(2.4,2.6) =(22.214.171.124)×10-4. Inclusion of data from the interval 2.22.4 GeV/c, where the lepton yield is dominated by bcl, gives Bub(2.2,2.6) =(126.96.36.199)×10-4. Vub/Vcb depends on the theoretical model of bul decay and is approximately 0.1.
ASJC Scopus subject areas
- Physics and Astronomy(all)