| |
 |
UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS Guest
2024-11-22 1:56 |
 |
|
|
|
Conference: Bucharest University Faculty of Physics 2010 Meeting
Section: Nuclear and Elementary Particles Physics
Title:
On the frictions among participant region and spectator regions in relativistic and ultrarelativistic nuclear collisions
Authors:
Al. Jipa (1), Georgia Andra Ibanescu (1), T. Eseanu (1), M.Calin(1)*, C. Besliu (1), V. Covlea (2), Stefania Velica (1), A. Jinaru (1), A. Scurtu (1)
Affiliation:
(1)Atomic and Nuclear Physics Chair, Faculty of Physics, University of Bucharest, ROMANIA
(2) Optics, Spectroscopy, Plasma and Lasers Chair, Faculty of Physics, University of Bucharest, ROMANIA
E-mail
jipa@brahms.fizica.unibuc.ro
Keywords:
nucleus-nucleus collisions, relativistic energies, hydrodynamic flow, friction, viscosity, compressibility
Abstract:
One of the most used descriptions of the nucleus-nucleus collisions at relativistic and ultrarelativistic energies is the hydrodynamic one. Different types of hydrodynamic flow of the highly excited and dense nuclear matter formed in the overlapping region of the two colliding nuclei have been considered. Many hydrodynamic descriptions take into account the frictions among the participant regions and the spectator regions during the flow expansion. Taking into account the experimental results in different symmetric and non-symmetric nucleus-nucleus collisions in a large energies range a phenomenological geometric picture of these collisions has been proposed .This pictures permit to consider the friction degree between the two types of regions. Using this picture, the values of the compression coefficients and frictions between the two types of regions for many collisions at energies between 4,5 A GeV, in Laboratory System (LS) and 200 A GeV, in Centre of Mass System (CMS) have been evaluated. The most important results are related to the behaviours of the compression coefficients and global friction coefficients. If the first physical quantity increases with the increase of the incident energy, the second decrease with this energy. Other interesting observations can be obtained, too. These results could be correlated with the present predictions of the RHIC-BNL experiments that the quark-gluon plasma formation in Au-Au collisions at 200 A GeV, in CMS, is in a liquid phase.
|
|
|
|