2006/02/14 by M. Murray, Michael Murray, Murray, Michael +2
Physics and Astronomy · #Black Holes and Theoretical Physics #FOS: Physical sciences #High-Energy Particle Collisions Research #Nuclear Experiment (nucl-ex) #Quantum Chromodynamics and Particle Interactions #nucl-ex
paper · pdf · doi:10.48550/arxiv.nucl-ex/0602015
3 pages, 4 figures, Contribution to HEP2005 Conference, Lisbon, July 2005
arxiv created 2006/02/14 · openalex publication_date 2006/02/14 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
When heavy ions collide at ultra-relativistic energy, thousands of particles are emitted and it is reasonable to attempt to use hydrodynamic descriptions, with suitable initial conditions, to describe the time evolution of the collisons. In the longitudinal direction pions seem to exhibit Landau flow. This simple model assumes that all the entropy in the collisions is created the instant the two Lorentz contracted nuclei overlap and that the system then expands adiabatically. The system also displays radial and elliptic flow. Radial flow is manifested as a broadening of the pT distributions with respect to pp collisions. It is typically thought to result from multiple scattering of partons or hadrons before dynamic freeze-out. Elliptic flow occurs when heavy ions do not collide exactly head on. The initial geometrical asymetry is translated into a momentum asymetry via pressure gradiants. Since these gradients are self quenching, strong elliptic flow is thought to be linked to early thermalization and a large initial pressure. Using the concept of limiting fragmentation we attempt to sketch a link between the initial and final states of relativistic heavy ion collisions using new preliminary data from the BRAHMS collaboration on elliptic and radial flow.