Measurement of open charm production in d+Au collisions at

Abstract

We present the first comprehensive measurement of D0, D+, D*+ and their charge conjugate states at mid-rapidity in d+Au collisions at using the STAR TPC. The directly measured open charm multiplicity distribution covers a broad transverse momentum region of 0 < pT < 11 GeV/c. The measured dN/dy at mid-rapidity for D0 is 0.0265 ± 0.0036 (stat.), ± 0.0071 (syst.), and the measured D*+/D0 and D+/D0 ratios are approximately equal with a magnitude of 0.40 ± 0.09 (stat.) ± 0.13 (syst.). The total cross section per nucleon–nucleon collision extracted from this study is 1.18 ± 0.21 (stat.) ± 0.39 (syst.) mb. The direct measurement of open charm production is consistent with STAR single electron data. This cross section is higher than expectations from PYTHIA and other pQCD calculations. The measured pT distribution is harder than the pQCD prediction using the Peterson fragmentation function.