Open Charm Yields ind+AuCollisions atsNN=200GeV

Midrapidity open charm spectra from direct reconstruction of $D^0(\overline{D^0})\to K^{\mp }{\pi }^{\pm }$ in $d+\mathrm{A}\mathrm{u}$ collisions and indirect electron-positron measurements via charm semileptonic decays in $p+p$ and $d+\mathrm{A}\mathrm{u}$ collisions at $\sqrt{s_{NN}}=200\mathrm{G}\mathrm{e}\mathrm{V}$ are reported. The $D^0(\overline{D^0})$ spectrum covers a transverse momentum ($p_T$) range of $0.1<p_T<3\mathrm{G}\mathrm{e}\mathrm{V}/c$, whereas the electron spectra cover a range of $1<p_T<4\mathrm{G}\mathrm{e}\mathrm{V}/c$. The electron spectra show approximate binary collision scaling between $p+p$ and $d+\mathrm{A}\mathrm{u}$ collisions. From these two independent analyses, the differential cross section per nucleon-nucleon binary interaction at midrapidity for open charm production from $d+\mathrm{A}\mathrm{u}$ collisions at BNL RHIC is $d{\sigma }_{c\overline{c}}^{NN}/dy=0.30\pm 0.04(\mathrm{s}\mathrm{t}\mathrm{a}\mathrm{t})\pm 0.09(\mathrm{s}\mathrm{y}\mathrm{s}\mathrm{t})\mathrm{m}\mathrm{b}$. The results are compared to theoretical calculations. Implications for charmonium results in $A+A$ collisions are discussed.