Collisional Jet Energy Loss In Quark-Gulon Plasma

Relativistic heavy-ion collisions can create quark-gluon plasma(QGP),which has existed in early universe.Scientists hope to understand the strong interaction by studying the properties of QGP.Jet quenching provides an important probe to the hot and dense QGP created in high-energy nuclear collisions.Jet quenching is a phenomenon that occurs in relativistic heavy-ion collisions.High energy jets interact with the QCD matterleading to a significant reduction of their energies.Due to the asymptotic freedom property of QCD,high-energy scattering processes can be analyzed using perturbation theory.Jets can lose energy in quark-gluon plasmavia combination of medium-induced gluon radiation and elastic collisions.In this thesis,we focus on jet energy loss by elastic collisions with the constituents of QGP medium.In the first chapter,we review the standard model and the Lagrangian of QCD from gauge invariance.Then we introduce the the QCD running coupling and spon-taneous symmetry breaking.Then we introduce the properties of QGP relativistic heavy-ion collisions.Some important experimental evidences about QGP are intro-duced in the last section.In the second chapter,we provide a brief introduction to the concept and frame-work for the study of jet quenching.Thermal filed theory,hard thermal loop and dispersion relations are introduced.Then we study the jet energy loss via qq?qq,qq?qq and qg ? qg scaterring process in the QCD matter.The third chapter focus on numerical calculations.We first study the collisional energy loss of jets passing through static QCD medium with different temperatures and lengths.Then by using the medium evolution profile and temperature distribu-tion obtained from hydrodynamic model simulation,we study the collisional energy loss of light quark jets and gluon jets in dynamic QGP medium created in relativistic heavy-ion collision at RHIC and the LHC.The last chapter contains the summary and conclusion.