SUPERSYMMETRY REACH OF AN UPGRADED TEVATRON COLLIDER

We examine the capability of a $\sqrt{s}=2$ TeV Tevatron $p\bar p$ collider to discover supersymmetry, given a luminosity upgrade to amass $25\ fb^{-1}$ of data. We compare with the corresponding reach of the Tevatron Main Injector ($1\ fb^{-1}$ of data). Working within the framework of minimal supergravity with gauge coupling unification and radiative electroweak symmetry breaking, we first calculate the regions of parameter space accessible via the clean trilepton signal from $\tw_1\tz_2\to 3\ell +\eslt$ production, with detailed event generation of both signal and major physics backgrounds. The trilepton signal can allow equivalent gluino masses of up to $m_{\tg}\sim 600-700$ GeV to be probed if $m_0$ is small. If $m_0$ is large, then $m_{\tg}\sim 500$ GeV can be probed for $\mu <0$; however, for $\mu >0$ and large values of $m_0$, the rate for $\tz_2\to\tz_1\ell\bar{\ell}$ is suppressed by interference effects, and there is {\it no} reach in this channel. We also examine regions where the signal from $\tw_1\overline{\tw_1}\to \ell\bar{\ell}+\eslt$ is detectable. Although this signal is background limited, it is observable in some regions where the clean trilepton signal is too small. Finally, the signal $\tw_1\tz_2\to jets+\ell\bar{\ell} +\eslt$ can confirm the clean trilepton signal in a substantial subset of the parameter space where the trilepton signal can be seen. We note that although the clean trilepton signal may allow Tevatron experiments to identify signals in regions of parameter space beyond the reach of LEP II, the dilepton channels generally probe much the same region as LEP II.