We report measurements of charmed-hadron ($D^{ 0}$, $D^{ *}$) 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 $D^{ 0}\rightarrow K^{ -}\pi^{ +}$, $D^{ *+}\rightarrow D^{ 0}\pi^{ +}\rightarrow K^{ -}\pi^{ +}\pi^{ +}$ 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 $D^{ *+}$, respectively. From this analysis, the charm-pair production cross section at mid-rapidity is $d\sigma/dy|_{ y=0}^{ c\bar{ c}}$ = 170 $\pm$ 45 (stat.) $^{ +38}_{ -59}$ (sys.) $\mu$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.
Categories: nucl-ex