Anisotropic transverse flow and the quark-hadron phase transition
Abstract
We use (3+1)-dimensional hydrodynamics with exact longitudinal boost invariance to study the influence of collision centrality and initial energy density on the transverse flow pattern and the angular distributions of particles emitted near midrapidity in ultrarelativistic heavy-ion collisions. We concentrate on radial flow and the elliptic flow coefficient v2 as functions of the impact parameter and collision energy. We demonstrate that the finally observed elliptic flow is established earlier in the collision than the observed radial flow and thus probes the equation of state at higher energy densities. We point out that a phase transition from hadronic matter to a color-deconfined quark-gluon plasma leads to nonmonotonic behavior in both beam energy and impact parameter dependences which, if observed, can be used to identify such a phase transition. Our calculations span collision energies from the Brookhaven AGS (Alternating Gradient Synchrotron) to beyond the LHC (Large Hadron Collider); the QGP phase transition signature is predicted between the lowest available SPS (CERN Super Proton Synchrotron) and the highest RHIC (Brookhaven Relativistic Heavy Ion Collider) energies. To optimize the chances for applicability of hydrodynamics we suggest studying the excitation function of flow anisotropies in central uranium-uranium collisions in the side-on-side collision geometry.
- Publication:
-
Physical Review C
- Pub Date:
- November 2000
- DOI:
- 10.1103/PhysRevC.62.054909
- arXiv:
- arXiv:hep-ph/0006129
- Bibcode:
- 2000PhRvC..62e4909K
- Keywords:
-
- 25.75.-q;
- 24.10.Nz;
- 25.75.Ld;
- Relativistic heavy-ion collisions;
- Hydrodynamic models;
- Collective flow;
- High Energy Physics - Phenomenology;
- Nuclear Theory
- E-Print:
- 18 pages ReVTeX, including 14 postscript figures. Revised version with modified discussion of selecting side-on-side geometry in U+U collisions, pt-dependence of v2, and estimating thermalization time scale by measuring elliptic flow. Some references added. To appear in Physical Review C