Azimuthal anisotropy and correlations at large transverse momenta in p+p and Au+Au collisions at s(NN)**(1/2) = 200-GeV
Phys.Rev.Lett. 93 (2004) 252301, 2004.
The collaboration

Abstract (data abstract)
Results on high transverse momentum charged particle emission with respect to the reaction plane are presented for Au+Au collisions at $\sqrt{s_{NN}}$ = 200 GeV. Two- and four-particle correlations results are presented as well as a comparison of azimuthal correlations in Au+Au collisions to those in $p+p$ at the same energy. Elliptic anisotropy, $v_{2}$, is found to reach its maximum at $p_{t}$ ∼ 3 GeV/c, then decrease slowly and remain significant up to $p_{t} \approx$ 7 -- 10 GeV/c. Stronger suppression is found in the back-to-back high-pt particle correlations for particles emitted out-of-plane compared to those emitted in-plane. The centrality dependence of $v_{2}$ at intermediate pt is compared to simple models based on jet quenching.