Measurement of Prompt Charm Meson Production Cross Sections in $p\overline{p}$ Collisions at $\sqrt{s}=1.96\mathrm{T}\mathrm{e}\mathrm{V}$

We report on measurements of differential cross sections $d\sigma /d{p}_T$ for prompt charm meson production in $p\overline{p}$ collisions at $\sqrt{s}=1.96\mathrm{T}\mathrm{e}\mathrm{V}$ using $5.8\pm 0.3{\mathrm{p}\mathrm{b}}^{-1}$ of data from the CDF II detector at the Fermilab Tevatron. The data are collected with a new trigger that is sensitive to the long lifetime of hadrons containing heavy flavor. The charm meson cross sections are measured in the central rapidity region $|y|\le 1$ in four fully reconstructed decay modes: $D^0\to K^{-}{\pi }^{+}$, $D^{*+}\to D^0{\pi }^{+}$, $D^{+}\to K^{-}{\pi }^{+}{\pi }^{+}$, $D_s^{+}\to \phi {\pi }^{+}$, and their charge conjugates. The measured cross sections are compared to theoretical calculations.

Figure 1

Charm signals summed over all $p_T$ bins: (a) invariant mass distribution of $D^0\to K^{-}{\pi }^{+}$ candidates; (b) mass difference distribution of $D^{*+}\to D^0{\pi }^{+}$ candidates; (c) invariant mass distribution of $D^{+}\to K^{-}{\pi }^{+}{\pi }^{+}$ candidates; (d) invariant mass distribution of $D^{+}\to \phi {\pi }^{+}$ and $D_s^{+}\to \phi {\pi }^{+}$ candidates. The curves show the results of the fits described in the text.

Figure 2

The impact parameter distributions of the $D^0$ mesons, measured from the $\pm 2\sigma$ signal region of the invariant mass distribution and corrected for combinatoric background measured in the invariant mass sidebands. The solid curve is the fit result summed over all $p_T$ bins. The dashed curve shows the contribution of secondary charm from $B$ decay.

Figure 3

The measured differential cross section measurements for $|y|\le 1$, shown by the points. The inner bars represent the statistical uncertainties; the outer bars are the quadratic sums of the statistical and systematic uncertainties. The solid curves are the theoretical predictions from Cacciari and Nason [16], with the uncertainties indicated by the shaded bands. The dashed curve shown with the $D^{*+}$ cross section is the theoretical prediction from Kniehl [17]; the dotted lines indicate the uncertainty. No prediction is available yet for $D_s^{+}$ production.