Search for scalar top quarks in the acoplanar charm jets and missing transverse energy final state in $p\bar{p}$ collisions at $\sqrt{s}=1.96$ TeV

We present a search for the pair production of scalar top quarks, $\tilde{t}$, using 995 pb${}^{-1}$ of data collected in $p\bar{p}$ collisions with the D0 detector at the Fermilab Tevatron Collider at $\sqrt{s}=1.96$ TeV. Both scalar top quarks are assumed to decay into a charm quark and a neutralino (${\tilde{\chi }}_1^0$), where ${\tilde{\chi }}_1^0$ is the lightest supersymmetric particle. This leads to a final state with two acoplanar charm jets and missing transverse energy. We find the yield of such events to be consistent with the standard model expectation, and exclude sets of $\tilde{t}$ and ${\tilde{\chi }}_1^0$ masses at the 95% C.L. that substantially extend the domain excluded by previous searches.