Light quark jet quenching and the Gauge/Gravity duality

Abstract

In this dissertation, the gauge/gravity duality is used to study light quark jet quenching in the context of strongly coupled non-Abelian plasmas. In particular, we focus on using the so-called finite end point momentum strings to probe such plasmas. First, the Sakai-Sugimoto model is investigated using these strings. The stopping distance of thermalised light quarks and their rate of energy loss are computed. This stopping distance is then used to compute the transverse momentum broadening parameter . The Sakai-Sugimoto model shows less jet quenching than super Yang-Mills plasma. Both the super Yang-Mills and Sakai-Sugimoto cases over predict the jet quenching parameter relative to phenomenological models that extract from experimental data. Next, the impact of non-zero chemical potentials within the plasma has on light probe quenching is investigated. The two cases of interest are the finite -charged case and the finite baryon chemical potential. It is found that the baryon or flavour chemical potential has very little effect on the jet quenching relative to the -charged case. Finally, small anisotropy is added to the plasma and it is found that for fixed temperature, the anisotropy increases jet quenching for motion in all directions. The longitudinal direction increases the jet quenching parameter the most. However, the parameter decreases in the transverse direction for fixed entropy density.