Extract charm cross section from its semileptonic decay at RHIC

We propose a sensitive measurement of the charm total cross section at RHIC through muon identification from charm semileptonic decay at low transverse momentum (pT ). This can test the binary-collision scaling (Nbin) properties of the charm total cross section and be used to study if heavy-flavor quarks as a probe are produced exclusively at the initial impact. The effects of the form factor of the charm semileptonic decay on extracting the total charm cross section and on the shape of the lepton spectra are also discussed in detail. We conclude that lepton spectra from charmed hadron decays at transverse momentum pT ≃ 1.0 GeV/c are sensitive to the charmed hadron spectrum shape. Therefore, the interactions of heavy quarks with the medium created in relativistic heavy-ion collisions, especially the flow effects, can be extracted from the leptons from the charmed hadron decays at low pT .