Decays of Upsilon mesons to the J/Psi meson and a search for the Higgs boson in B meson decay

Wen-Ying Chen, Purdue University

Abstract

A search for $J$/$\Psi\to e\sp+e\sp-$ and $\mu\sp+\mu\sp-$ from $\Upsilon$ decays has been studied with the CLEO detector at the Cornell Electron Storage Ring. The inclusive branching ratio for $\Upsilon$(1S) decay to $J$/$\Psi$ is measured to be (0.11 $\pm$ 0.04 $\pm$ 0.02)%. For $\Upsilon$(4S)$\to B\bar B$ with $B\to J$/$\Psi$ the inclusive branching ratio is measured to be (1.12 $\pm$ 0.10 $\pm$ 0.23)%. Exclusive decay modes of the B mesons to two bodies, $\Psi K$ and $\Psi K\sp\*$, and multi-bodies, $\Psi K\pi$ and $\Psi K\pi\pi$, also have been measured. Evidence for B decay to $\Psi\sp\prime$ is reported. Finally, the $\Psi$ momentum spectrum has been studied. The low momentum spectrum is dominated by cascade decay of $\Psi m\sp\prime$ to $\Psi\pi\pi$ and the high momentum spectrum is dominated by two body decay to $\Psi K$ and $\Psi K\sp\*$. A peak in the $\Psi$ momentum spectrum at 1 GeV/c suggests that three and four body decays contribute a substantial amount to the spectrum. Since there is no theoretical prediction for the Higgs mass, a search for the b quark decay to an s quark and Higgs has been performed, where the Higgs decays to $\mu\sp{+}\mu\sp{-}$, $\pi\sp{+}\pi\sp{-}$ and $K\sp{+}K\sp{-}$. The upper limit of the Higgs to two body decay modes has been obtained, and we have excluded the Higgs in the mass range from 0.3 to 3.6 GeV.

Degree

Ph.D.

Advisors

Shibata, Purdue University.

Subject Area

Particle physics

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