DD momentum correlations versus relative azimuth as a sensitive probe for thermalization

In high-energy nuclear collisions at LHC, where a QGP might be created, the degree of thermalization at the partonic level is a key issue. Due to their large mass, heavy quarks are a powerful tool to probe thermalization. We propose to measure azimuthal correlations of heavy-quark hadrons and their decay products. Changes or even the complete absence of these initially existing azimuthal correlations in Pb− Pb collisions might indicate thermalization at the partonic level. We present studies with PYTHIA for p − p collisions at 14 TeV using the two-particle transverse momentum correlator 〈∆pt,1∆pt,2〉 as a sensitive measure of potential changes in these azimuthal correlations. Contributions from transverse radial flow are estimated.