Leptonic Decays of the Charged B Meson

Thesis/Dissertation · Tue Jan 01 00:00:00 EST 2008

DOI:https://doi.org/10.2172/981681· OSTI ID:981681

Corwin, Luke A. ^[1]

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1. The Ohio State Univ., Columbus, OH (United States)

We present a search for the decay B⁺ → ℓ⁺ν ( = τ, μ, or e) in (458.9±5.1)×10⁶ Υ(4S) decays recorded with the BABAR detector at the SLAC PEP-II B-Factory. A sample of events with one reconstructed exclusive semi-leptonic B decay (B^- → D⁰ℓ ^-$$\bar{v}$$X) is selected, and in the recoil a search for B⁺ →ℓ +ν_ℓ signal is performed. The τ is identified in the following channels: τ⁺ → e⁺ν_e$$\bar{v}$$_τ , τ⁺ → μ⁺ν_μ$$\bar{v}$$_τ , τ⁺ → π⁺$$\bar{v}$$_τ , and τ⁺ → π⁺π⁰$$\bar{v}$$_τ . The analysis strategy and the statistical procedure is set up for branching fraction extraction or upper limit determination. We determine from the dataset a preliminary measurement of B(B⁺ → τ⁺ν_τ) = (1.8 ± 0.8 ± 0.1) × 10^-4, which excludes zero at 2.4σ, and f_B = 255 ± 58 MeV. Combination with the hadronically tagged measurement yields B(B⁺ → τ⁺ν_τ) = (1.8 ± 0.6) × 10^-4. We also set preliminary limits on the branching fractions at B(B⁺ → e⁺ν_e) < 7.7 × 10^-6 (90% C.L.), B(B⁺ → μ⁺ν_μ) < 11 × 10^-6 (90% C.L.), and B(B⁺ → τ⁺ν_τ ) < 3.2 × 10^-4(90% C.L.).

• Research Organization: SLAC National Accelerator Lab., Menlo Park, CA (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: AC02-76SF00515
• OSTI ID: 981681
• Report Number(s): SLAC-R-914; TRN: US1004090
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
B MESONS
DECAY
LEPTONIC DECAY
STANFORD LINEAR ACCELERATOR CENTER
Phenomenology-HEP
HEPEX