Azimuth Quadrupole Systematics in Au-Au Collisions

الأصل · EN

We have measured pₜ-dependent two-particle number correlations on azimuth and pseudorapidity for eleven centralities of √sNN = 62 and 200 GeV Au-Au collisions at STAR. 2D fits to these angular correlations isolate the azimuth quadrupole amplitude, denoted 2 v₂² { 2D } (pₜ), from localized same-side correlations. Event-plane v₂ (pₜ) measurements within the STAR TPC acceptance can be expressed as a sum of the azimuth quadrupole and the quadrupole component of the same-side peak. v₂ { 2D } (pₜ) can be transformed to reveal quadrupole pₜ spectra which are approximately described by a fixed transverse boost and universal Lévy form nearly independent of centrality. A parametrization of v₂ { 2D } (pₜ) can be factored into centrality and pₜ-dependent pieces with a simple pₜ dependence above 0.75 GeV/c. Results from STAR are compared to published data and model predictions.