Cherenkov Radiation from Jets in Heavy-ion Collisions

TL;DR

It is argued that detailed spectroscopy of jet correlations can directly probe the index of refraction of this matter, which in turn will provide information about the mass scale of these partonic bound states.

Abstract

The possibility of Cherenkov-like gluon bremsstrahlung in dense matter is studied. We point out that the occurrence of Cherenkov radiation in dense matter is sensitive to the presence of partonic bound states. This is illustrated by a calculation of the dispersion relation of a massless particle in a simple model in which it couples to two different massive resonance states. We further argue that detailed spectroscopy of jet correlations can directly probe the index of refraction of this matter, which in turn will provide information about the mass scale of these partonic bound states.

Figures (5)

• Figure 1: The general contribution to the self-energy of $\Phi$ due to transitional interaction.
• Figure 2: The real (solid) and imaginary part (dotted) of the full self-energy and the first two contributions (dashed and dot-dashed) from Eq. (\ref{['phi_se']}).
• Figure 3: The dispersion relation of $\Phi$ in a thermal medium with transitional coupling to two massive particles. The diagonal line represents the light-cone.
• Figure 4: The real and imaginary parts of $\Pi(p^0,p)$ for $p^0,p$ which satisfy the quasi-particle dispersion relation. The choice of parameters and the legends for the real parts are the same as in Fig. \ref{['fig3']}.
• Figure 5: Dependence of the Cherenkov angle on momentum of the emitted particle.