Formation of a perfect fluid in high-energy heavy-ion collisions

摘要

One of the main goals of the experiments involving high-energy heavy-ion collisions is to create a high-temperature state of matter where quarks and gluons, the basic constituents of matter, are no longer confined inside hadrons (like protons and neutrons). This state of matter is commonly referred to as the quark gluon plasma (QGP). Such a de-confined state of matter will allow us to study properties like shear viscosity, thermal conductivity and diffusion for a thermodynamic system of quarks and gluons – a study that would not have been otherwise possible using a system of commonly observed hadrons in nature. It is like properties of hydrogen and oxygen that cannot necessarily be gauged by studying the properties of water. Both hydrogen and oxygen facilitate burning in contrast to that of water. There are compelling evidences that collisions of gold and lead nuclei at the Relativistic Heavy Ion Collider (RHIC) facility at Brookhaven National Laboratory and Large Hadron Collider (LHC) facility at CERN respectively, have produced such a de-confined state of matter 1 , thereby providing a unique opportunity to study the properties of a thermodynamic system of quarks and gluons.