Abstract
Azimuthal anisotropy ([Formula presented]) and two-particle angular correlations of high [Formula presented] charged hadrons have been measured in [Formula presented] collisions at [Formula presented] for transverse momenta up to [Formula presented], where hard processes are expected to contribute significantly. The two-particle angular correlations exhibit elliptic flow and a structure suggestive of fragmentation of high [Formula presented] partons. The monotonic rise of [Formula presented] for [Formula presented] is consistent with collective hydrodynamical flow calculations. At [Formula presented], a saturation of [Formula presented] is observed which persists up to [Formula presented].