Azimuthal correlations of charm

Azimuthal correlation of heavy quarks produced at LHC, can be one of the most powerful and discerning probes for quark gluon plasma. Heavy quarks suffer energy loss which manifests through changes in nuclear modification factor, RAA. On the other hand, azimuthal correlation of heavy quark will be sensitive to diffusion through quark gluon plasma, as the heavy quarks undergo collisions and radiate gluons. In the present work the azimuthal correlation of heavy quarks for proton-proton collisions as well as for lead-lead collisions have been presented for prompt interaction and other secondary multiple scatterings. The effect of collective flow on the correlation of the heavy quarks have also been studied