Measurement of open charm production in d+Au collisions at

Abstract

We present the first comprehensive measurement of $D^{0}, D^{+}, D^{*+}$ and\ntheir charge conjugate states at mid-rapidity in $d$+Au collisions at\n$\\sqrt{s_{_{NN}}}$=200 GeV using the STAR TPC. The directly measured open charm\nmultiplicity distribution covers a broad transverse momentum region of\n0$<p_{T}<11$ GeV/$c$. The measured $dN/dy$ at mid-rapidity for $D^{0}$ is\n$0.0265\\pm 0.0036 (stat.) \\pm 0.0071 (syst.)$ and the measured $D^{*+}/D^{0}$\nand $D^{+}/D^{0}$ ratios are approximately equal with a magnitude of $0.40\\pm\n0.09(stat.) \\pm 0.13(syst.)$. The total $c\\bar{c}$ cross section per\nnucleon-nucleon collision extracted from this study is $1.18 \\pm 0.21(stat.)\n\\pm 0.39(syst.) $mb. The direct measurement of open charm production is\nconsistent with STAR single electron data. This cross section is higher than\nexpectations from PYTHIA and other pQCD calculations. The measured $p_{T}$\ndistribution is harder than the pQCD prediction using the Peterson\nfragmentation function.\n