Open Charm Production at STAR

The study of open charm hadrons provides valueable test of the perturbative
QCD predictions for heavy quark production. Their production and spectra are
sensitive to the initial parton distribution function in nucleons. Their
relatively reduced energy loss due to the "deadcone effect" will help to
distinguish the medium in which the jet loses its energy. The open charm
spectra at mid-rapidity from direct reconstruction of D0, D* and D+/- are
presented in d+Au collisions at \sqrt{s_{NN}}=200 GeV using the STAR
detector at RHIC. The indirect electron/positron measurements via charm
semileptonic decay in p+p and d+Au collsions are also reported. The total
cc-bar cross section per nucleon-nucleon collsions are extracted from both
direct and indirect measurements and are consitent. The open charm pT
distribution from direct measurement covers the pT range up to 10 GeV/c and
is compared to model predictions. Physics indications of these measurements
are discussed.