Measurement of charm flow with the STAR Heavy Flavour Tracker

In order to understand the partonic EOS of matter created at RHIC, one needs to study both the collectivity of the produced matter and the degree of thermalization. Anisotropic flow measurements have already demonstrated the development of partonic collectivity at RHIC (Ackermann K et al 2001 Phys. Rev. Lett. 86 402), and now it is necessary to address the issue of quark thermalization. Since the masses of the heavy flavour quarks are larger than the possible excitations of the system created in the collision, their collective motion could be used to indicate the degree of thermalization of the light flavour quarks (u, d, s). The Heavy Flavour Tracker (HFT), a tracking upgrade of the STAR experiment, is being designed to provide an unambiguous measurement of charm quark flow through the direct reconstruction of the D0. The current design of our detector uses a novel CMOS-based sensor, allowing for a low mass and high resolution detector element