Heavy mesons in a simple quark-confining two-step potential model

We study the mass spectra and decay widths of UPSILON resonances in a simple quark-confining, analytically solvable, two-step potential model used earlier to study the charmonium system and even the light mesons such as ..pi.., rho, K,... Results are found to be in good agreement with experiments and also with the values predicted by others. We predict the BB-bar threshold at 10.242 GeV, which means in our model the first three radial UPSILON excitations UPSILON(9.4345), UPSILON'(9.9930), and UPSILON''(10.1988) are stable with respect to the Zweig-rule-allowed decay UPSILON..-->..BB-bar. The mass spectrum and thresholds of the anticipated tt-bar states are also studied as a function of quark mass.