Download or read book Momentum Broadening and Collinear Radiation in a Non-equilibrium Quark-gluon Plasma written by Sigtryggur Hauksson and published by . This book was released on 2022 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "Heavy-ion collisions produce high-temperature strongly interacting matter known as the quark-gluon plasma. The plasma is out of thermal equilibrium at all stages of its evolution and thus provides a window into transport coefficients and hydrodynamization of non-equilibrium quantum chromodynamics (QCD): the theory of the strong force. Jets and photons are two experimental probes that are particularly sensitive to the evolution of the plasma, including its non-equilibrium properties. In order to use these probes to study non-equilibrium QCD, a thorough understanding of the physics of jets and photons in a non-equilibrium plasma is needed. This includes transverse momentum broadening of jet partons, as well as the collinear bremsstrahlung of photons and gluons. In this thesis, we evaluate the rate of transverse momentum broadening of a parton in a non-equilibrium plasma. This is done by calculating the occupation density of soft gluons radiated by medium particles which are assumed to be anisotropically distributed in momentum space. Our results show that momentum broadening is reduced relative to a plasma in equilibrium because of increased screening. We furthermore establish that spurious divergences in the rate of momentum broadening are due to plasma instabilities and are cured when time evolution of the plasma is taken into account. To do this we evaluate analytically the time evolution of two-point gluon correlators in an unstable plasma. Finally, we analyze collinear bremsstrahlung of photons and gluons in a non-equilibrium plasma. Our calculation includes the Landau-Pomeranchuk-Migdal effect. We develop numerical methods to calculate the bremsstrahlung rate in an anisotropic plasma and show that the rate of photon production is reduced compared with thermal equilibrium, especially at higher photon momenta"--