Azimuthal anisotropy: transition from hydrodynamic flow to jet suppression
May, 2010
Citations per year
Abstract: (arXiv)
Measured 2nd and 4th azimuthal anisotropy coefficients v_{2,4}(N_{part}), p_T) are scaled with the initial eccentricity \varepsilon_{2,4}(N_{part}) of the collision zone and studied as a function of the number of participants N_{part} and the transverse momenta p_T. Scaling violations are observed for p_T \alt 3 GeV/c, consistent with a dependence of viscous corrections and a linear increase of the relaxation time with . These empirical viscous corrections to flow and the thermal distribution function at freeze-out constrain estimates of the specific viscosity and the freeze-out temperature for two different models for the initial collision geometry. The apparent viscous corrections exhibit a sharp maximum for p_T \agt 3 GeV/c, suggesting a breakdown of the hydrodynamic ansatz and the onset of a change from flow-driven to suppression-driven anisotropy.Note:
- 5 pages, 4 figs; submitted for publication
- 25.75.Nq
- 25.75.Dw
- 25.75.Ld
- heavy ion: scattering
- gold
- freeze-out: temperature
- scaling: violation
- viscosity
- flow: anisotropy
- hydrodynamics
References(39)
Figures(4)