Measurement of charm production cross-section and leptons from its semileptonic decay at RHIC

In this thesis, we present the measurements of $D^0\to K\pi$ at low $p_T$ ($p_T\le 2$ GeV/$c$) and non-photonic electron spectra ($0.9\le p_T\le 5$ GeV/$c$) from $D^0$ semi-leptonic decay. In addition, we use a newly proposed technique to identify muons from charm decays at low $p_T$. The combination of all these three measurements stringently constrains the total charm production cross-section at mid-rapidity at RHIC. They also allow the extraction of the charmed hadron spectral shape and a study of possible charm radial flow in Au+Au collisions.