Measurement of the $t\overline{t}$ Production Cross Section in $p\overline{p}$ Collisions at $\sqrt{s}=1.96\mathrm{TeV}$ Using Missing $E_T+\mathrm{\text{jets}}$ Events with Secondary Vertex $b$ Tagging

We present a measurement of the $t\overline{t}$ production cross section in $p\overline{p}$ collisions at $\sqrt{s}=1.96\mathrm{TeV}$ which uses events with an inclusive signature of significant missing transverse energy and jets. This is the first measurement which makes no explicit lepton identification requirements, so that sensitivity to $W\to \tau \nu$ decays is maintained. Heavy flavor jets from top quark decay are identified with a secondary vertex tagging algorithm. From $311{\mathrm{pb}}^{-1}$ of data collected by the Collider Detector at Fermilab, we measure a production cross section of $5.8\pm 1.2(\mathrm{stat}{)}_{-0.7}^{+0.9}(\mathrm{syst})\mathrm{pb}$ for a top quark mass of $178\mathrm{GeV}/c^2$, in agreement with previous determinations and standard model predictions.

Figure 1

Tagging rate probability parametrization in the multijet sample as a function of (a) jet $E_T$, (b) track multiplicity, and (c) missing $E_T$ projection.

Figure 2

Ratio of observed to expected $b$ tags as a function of the number of jets in the data before the optimized kinematical selection on ${\mathrm{E̸}}_T^{\mathrm{sig}}$ and $\min \Delta \varphi ({\mathrm{E̸}}_T,\mathrm{\text{jets}})$ (a) and in control samples: ${\mathrm{E̸}}_T^{\mathrm{sig}}\le 3.0{\mathrm{GeV}}^{1/2}$, $\min \Delta \varphi ({\mathrm{E̸}}_T,\mathrm{\text{jets}})\ge 0.3\mathrm{rad}$ (b) and ${\mathrm{E̸}}_T^{\mathrm{sig}}\ge 3.0{\mathrm{GeV}}^{1/2}$, $\min \Delta \varphi ({\mathrm{E̸}}_T,\mathrm{\text{jets}})\le 0.3\mathrm{rad}$ (c).

Figure 3

$\Delta \varphi ({\mathrm{E̸}}_T,\mathrm{\text{tagged jet}})$ distribution for data after kinematical selection and with at least one $b$-tagged jet. The data are fit to the sum of $t\overline{t}$ signal and background templates as described in the text.