Search for the decay positive B meson decays to eta meson (positive lepton) lepton neutrino

Shenjian Chen, Purdue University

Abstract

Using a sample of 9.66 × 106 BB¯ events collected with the CLEO II/II.V detector at the Cornell Electronic Storage Ring (CESR), we search for B+ → ηℓ +νℓ decay by performing a 3-dimensional unbinned maximum likelihood fit. We find [special characters omitted] signal events, corresponding to a branching fraction of [special characters omitted](B+ → ηℓ+ν ℓ) = ([special characters omitted]) × 10−4. The statistical significance of the signal yield is 2.7σ, the combined statistical and systematic significance is 2.4σ. Therefore we also report the result as an upper limit: [special characters omitted](B+ → ηℓ+ν ℓ) < 0.72 × 10−4 at 90% C.L. The central value is below the ISGW2 model prediction by about a factor two. The ISGW2 model assumes that the η–η′ mixing angle, &thetas; P, is −20°. This result favors a smaller negative value for &thetas;P.

Degree

Ph.D.

Advisors

Shipsey, Purdue University.

Subject Area

Particle physics

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