Photon Signals from Quarkyonic Matter

Abstract

We calculate the bremsstrahlung photon spectrum emitted from dynamically evolving "quarkyonic" matter and compare this spectrum with that of a high chemical potential quark-gluon plasma as well as to a hadron gas. We find that the transverse momentum distribution and the harmonic coefficient is markedly different in the three cases. The transverse momentum distribution of quarkyonic matter can be fit with an exponential but is markedly steeper than the distribution expected for the quark-gluon plasma or a hadron gas, even at the lower temperatures expected in the critical point region. The quarkyonic elliptic flow coefficient fluctuates randomly from event to event and within the same event at different transverse momenta. The latter effect, which can be explained by the shape of quark wave functions within quarkyonic matter, might be considered as a quarkyonic matter signature, provided that the initial temperature is low enough that the quarkyonic regime dominates over deconfinement effects and the reaction-plane flow can be separated from the fluctuating component.