Quarkonium Dissociation as A Probe of Color Screening in Hot QCD Medium

Abstract

Matter is expected to undergo a transition from confined to deconfined quarks as its basic newlineconstituents, at sufficiently high temperatures or densities. This statement is, according to newlinequantum chromodynamics (QCD), where in confined phase; quarks and gluons these coloured newlineconstituents are bound to colour-neutral hadrons, while in the deconfined quark-gluon plasma newline(QGP), there are freely moving colour charges. By the late 1980s, on producing QGP under newline laboratory conditions have started in the world leading particle physics facilities at CERN newline(Conseil EuropA c en pour la Recherche NuclA c aire, Geneva, Switzerland) and Brookhaven newlineNational Laboratory (BNL, New York, NY, USA) [1 3]. In the year 2000, CERN announced newlinecircumstantial evidence for the creation of a new state of matter in Pb + Pb collisions [4] after newlinefinishing the main part of its heavy-ion program at the Super Proton Synchrotron (SPS) newlineaccelerator. In 2005, the real discovery of QGP took place, when four international newlinecollaborations studying Au + Au collisions at the Relativistic Heavy Ion Collider (RHIC) at BNL newlineannounced the results of their first five years of measurements [5 8]. Surprisingly, the properties newlineof the new state of matter differed markedly from the predictions which were made during years newlinebefore its discovery. The present thesis comprises seven chapters. In Chapter 1, we have newlinereviewed the current status of our understanding regarding the properties of QGP with a brief newline in troduction of QCD and various theoretical tools e.g. lattice QCD and its predictions, and newlinehydrodynamics etc. which are being used to understand the different aspects of quark-hadron newlinephase transition. newline