Search for Light Top Squarks in $\mathit{p}\overline{p}$ Collisions at $\surd \mathit{s}=1.8\mathrm{}$ TeV

We present a search for pair produced top squarks, the supersymmetric partners of the top quark, using the D0 detector at the Fermilab Tevatron $p\overline{p}$ collider. We consider a scenario in which the lighter of the two top squarks ${\tilde{t}}_1$ decays with 100% branching fraction to a charm quark and the lightest neutralino ${\tilde{\chi }}_1^0$ yielding a signal of two acollinear jets with missing transverse energy. We observe 3 events while we expect $3.5\pm 1.2$ events from the known standard model processes. We exclude at the 95% confidence level a significant region of the $m_{{\tilde{t}}_1}$- $m_{{\tilde{\chi }}_1^0}$ parameter space. The highest $m_{{\tilde{t}}_1}$ value we exclude is $93\mathrm{GeV}{/c}^2$ with a corresponding $m_{{\tilde{\chi }}_1^0}$ value of $8\mathrm{G}\mathrm{e}\mathrm{V}/c^2$.