Measurement of rare decays of the b quark
Abstract
Using a data sample of 2.6 million B overlineB pairs produced at the ϒ(4S) taken with the CLEO-II detector at the Cornell Electron Storage Ring (CESR) we have searched for 2-body rare hadronic and semileptonic decays of the B-meson, involving the b → u transition. We measure the branching fraction of the sum of B 0 → π+π- and B 0 → K +π- to be (1.8 -0.5-0.3+0.6+0.2 ± 0.2) × 10 -5 and place upper limits in the range from 10 -4 to 10 -6 on other rare hadronic decays. For exclusive semileptonic b → u processes (using the ISGW model for efficiencies), we find braching ratios B(B 0 → π -ℓ +ν) = (1.34 ± 0.35 ± 0.28) × 10 -4, and B(B 0 → ϱ -ℓ +ν) = (2.28±0.36±0.59 -0.46+0.00) × 10 -4 and the ratio of widths {Γ( B 0 → ϱ -ℓ +ν) }/{Γ( B 0 → π -ℓ +ν) } = 1.70 -0.05+0.81±0.58 -0.34+0.00. If instead of ISGW one uses the WSB model, one finds B(B 0 → π -ℓ +ν) = (1.63 ± 0.46 ± 0.34) × 10 -4, B(B 0 → ϱ -ℓ +ν) = (3.88±0.54±1.01 -0.78) +0.00 × 10 -4, and {Γ( B 0 → ϱ -ℓ +ν) }/{Γ( B 0 → π -ℓ +ν) } = 2.39 -0.69+1.18±0.81 -0.48+0.00.
- Publication:
-
Nuclear Instruments and Methods in Physics Research A
- Pub Date:
- February 1995
- DOI:
- 10.1016/0168-9002(95)00989-2
- Bibcode:
- 1995NIMPA.368...41M