First Measurement of $W$ Boson Production in Association with a Single Charm Quark in $p\overline{p}$ Collisions at $\sqrt{s}=1.96\mathrm{TeV}$

We present the first measurement of the production cross section of a $W$ boson with a single charm quark ($c$) in $p\overline{p}$ collisions at $\sqrt{s}=1.96\mathrm{TeV}$, using soft muon tagging of $c$ jets. In a data sample of $\sim 1.8{\mathrm{fb}}^{-1}$, recorded with the Collider Detector at Fermilab II detector at the Fermilab Tevatron, we select events with $W+1$ or 2 jets. We use the charge correlation between the $W$ and the muon from the semileptonic decay of a charm hadron to extract the $Wc$ signal. We measure ${\sigma }_{Wc}(p_{Tc}>20\mathrm{GeV}/c,|{\eta }_c|<1.5)\times \mathrm{BR}(W\to \ell \nu )=9.8\pm 3.2\mathrm{pb}$, in agreement with theoretical expectations.

Figure 1

SS-subtracted distributions of the SLT muon $p_T$ relative to (a) the beam axis and (b) the SLT-jet axis. The $Wc$ contribution is normalized to this measurement.