Open Charm Yields in 200 GeV p+p and d+Au Collisions at RHIC

Abstract

Open charm spectra at mid-rapidity from direct reconstruction of $D^0\to K\pi$ and indirect electron/positron measurements via charm semileptonic decay in p+p and d+Au collisions at $\sqrt{s_{{}_{\mathrm{NN}}}}$ = 200 GeV are reported. The combined spectra cover open charm transverse momentum range $0.1{}_{\sim }^{<}{p}_T{}_{\sim }^{<}6$ GeV/$c$. The electron spectra show approximate binary scaling between p+p and d+Au collisions. From these two independent analyses, the differential cross section per nucleon-nucleon interaction at mid-rapidity for open charm production at RHIC is $d{\sigma }_{c\bar{c}}^{NN}/dy$=0.31$\pm$0.04(stat.)$\pm$0.08(syst.) mb. The next-to-leading-order pQCD calculation underpredicts the charm yields.

4 pages, 4 figures, QM 2004 contribution