Measurements of $D^0$ and $D^{\ast }$ Production in $p$ + $p$ Collisions at $\sqrt{s}$ = 200 GeV

Abstract

We report measurements of charmed-hadron ($D^0$, $D^{\ast }$) production cross sections at mid-rapidity in $p$ + $p$ collisions at a center-of-mass energy of 200 GeV by the STAR experiment. Charmed hadrons were reconstructed via the hadronic decays $D^0\to K^{-}\ddot{I}{€}^{+}$, $D^{\ast +}\to D^0\ddot{I}{€}^{+}\to K^{-}\ddot{I}{€}^{+}\ddot{I}{€}^{+}$ and their charge conjugates, covering the $p_T$ range of 0.6$-$2.0 GeV/$c$ and 2.0$-$6.0 GeV/$c$ for $D^0$ and $D^{\ast +}$, respectively. From this analysis, the charm-pair production cross section at mid-rapidity is $d\ddot{I}ƒ/dy{|}_{y=0}^{c\bar{c}}$ = 170 $\pm$ 45 (stat.) ${}_{-59}^{+38}$ (sys.) $\hat{I}¼$b. The extracted charm-pair cross section is compared to perturbative QCD calculations. The transverse momentum differential cross section is found to be consistent with the upper bound of a Fixed-Order Next-to-Leading Logarithm calculation.

15 pages, 16 figures. Revised version submitted to Phys. Rev. D