Search for flavor changing neutral current decay neutral D meson going to positive muon muon produced in 800 GeV/c proton-silicon interactions

This thesis presents a search for the flavor changing neutral current (FCNC) decay, $D\sp0 \to \mu\sp+\mu\sp-$, in 800 GeV/c proton-silicon interactions. FCNC is highly suppressed in the standard model, and $D\sp0 \to \mu\sp+\mu\sp-$ is expected to occur with a branching ratio around 10$\sp{-16}$. However, some models predict a much larger branching ratio of $\sim$10$\sp{-9}$. Therefore, the decay $D\sp0 \to \mu\sp+\mu\sp-$ provides an important test of the standard model. A total of 33.5 million dimuon events from the E771 experiment in Fermilab were analyzed. The dimuon invariant mass spectrum between 0.3-8.0 GeV/c$\sp2$ was studied in detail. Dimuon resonances of $\rho\sp0$, $\omega$, $\phi$, $J/\psi$, and $\psi\sp\prime$ were observed. Their production cross sections, masses, and the full width of $\rho\sp0$ were measured. No evidence was found for the FCNC decays, $D\sp0 \to \mu\sp+\mu\sp-$ and $B\sp0 \to \mu\sp+\mu\sp-$. An upper limit for the $D\sp0 \to \mu\sp+\mu\sp-$ (or $\bar D\sp0 \to \mu\sp+\mu\sp-$) decay branching ratio was determined to be $<$1.1 $\times$ 10$\sp{-5}$, which is equally stringent as the published current upper limit of $<$1.1 $\times$ 10$\sp{-5}$.