The Fast Life of Holographic Mesons

摘要

Holographic techniques are used to study the dispersion relation of mesonquasiparticles moving through a thermal plasma in N = 2 super-Yang-Millstheory with N, colours and coupled to N1 flavours of fundamental matter inthe regime Nf/Ne 1. The meson states are destabilized by introducing asmall quark density nq. Holographic spectrarfunctions are used to investigatethe dispersion relations and widths of these quasiparticles. In a low momentumregime q < q_max the quasiparticles approach a limiting velocity that can besignificantly less than the speed of light. In this regime, the widths of thequasiparticles also rise dramatically as the momentum approaches q_max Thespectral functions do not display isolated resonances for q > qmax. However, bystudying the dual quasinormal modes one can extend the dispersion relationinto this regime. We give a qualitative argument suggesting that the groupvelocity rises to the speed of light for q qmax. This contribution provides asummary of the results in [1].