Inclusive spectra in the upsilon energy region and a study of quark-jet versus gluon-jet fragmentation
Abstract
A study of particle yields from $\Upsilon$ and $\chi\sbsp{b}{\prime}$ states has been performed using the CLEO II detector operating at the Cornell Electron Storage Ring (CESR). The $\chi\sbsp{b}{\prime}$ states are tagged by their associated photon lines from decay of the $\Gamma$(3S). Produced particle species are identified using specific ionization, time-of-flight measurements, and vertex reconstruction. The momentum spectra of $\pi\sp\pm$, K$\sp\pm$, p, p, K$\sbsp{\rm s}{0}$, $\pi\sp0$, $\Lambda\sp0$, $\phi\sp0$, D$\sp0$, $\rho\sp0$, K$\sp{*0}$, and $e\sp\pm$ produced from $\chi\sbsp{b}{\prime}$ decay are measured, and comparisons are made to spectra obtained at the $\Upsilon($1S), $\Upsilon($3S), $\Upsilon($4S), and nearby continuum center-of-mass energy regions. The decays of $\chi\sbsp{b}{\prime}$ with $J=1$ are found to exhibit properties most similar to those observed in continuum qq decays, while the properties of the $\chi\sbsp{b}{\prime}$ with $J=0$ and 2 are most like the ggg decays of the $\Upsilon$(1S) state. Fragmentation functions are measured and quantitative and qualitative comparisons are made between the hadronization of quarks and that of gluons. A suggestion is given for a purely empirical treatment of the fragmentation of quark-jets versus gluon-jets.
Degree
Ph.D.
Advisors
Shibata, Purdue University.
Subject Area
Particle physics
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