Nettsider med emneord «Theoretical physics»
Ultra-relativistic heavy-ion collisions offer a unique opportunity to study the nuclear phase diagram at high temperatures and densities. The matter under such extreme conditions probably has existed in the early Universe within the first few fm/c after the Big Bang. Therefore, it is very tempting to investigate the properties of the Little Big Bang in the laboratory, and to search for a new state of matter, predicted by the fundamental theory of strong interactions - Quantum Chromodynamics (QCD), namely, a plasma of deconfined quarks and gluons or quark-gluon plasma (QGP).
To describe such complex phenomenon one has to rely on phenomenological models, which can be subdivided into macroscopic, i.e. thermal and hydrodynamic, and microscopic Monte Carlo models, incorporating partonic and hadronic degrees of freedom in a consistent fashion. These models are indispensable for the comparison with the experimental data coming from current heavy-ion accelerators and for planning the new machines such as FAIR at GSI, NICA at JINR, and FCC at CERN, which is widely discussed nowadays.
In Oslo we use several MC models at our disposal, namely, Ultra-relativistic Quantum Molecular Dynamics (UrQMD) and Quark-Gluon String Model (QGSM) for description of various hadronic and nuclear collisions, and HYDrodynamics with JETs (HYDJET++) model for simulation of heavy-ion collisions.
Tomi Koivisto, University of Tartu.