TY  - JOUR
PB  - SciPost Foundation
DO  - 10.21468/SciPostPhysCore.7.2.015
TI  - Speed of sound in dense strong-interaction matter
PY  - 2024/04/05
UR  - https://www.scipost.org/SciPostPhysCore.7.2.015
JF  - SciPost Physics Core
JA  - SciPost Phys. Core
VL  - 7
IS  - 2
SP  - 015
A1  - Braun, Jens
AU  - Geißel, Andreas
AU  - Schallmo, Benedikt
AB  - We study the speed of sound in strong-interaction matter at zero temperature and in density regimes which are expected to be governed by the presence of a color-superconducting gap. At (very) high densities, our analysis indicates that the speed of sound approaches its asymptotic value associated with the non-interacting quark gas from below, in agreement with first-principles studies which do not take the presence of a color-superconducting gap into account. Towards lower densities, however, the presence of a gap induces an increase of the speed of sound above its asymptotic value. Importantly, even if gap-induced corrections to the pressure may appear small, we find that derivatives of the gap with respect to the chemical potential can still be sizeable and lead to a qualitative change of the density dependence of the speed of sound. Taking into account constraints on the density dependence of the speed of sound at low densities, our general considerations suggest the existence of a maximum in the speed of sound. Interestingly, we also observe that specific properties of the gap can be related to characteristic properties of the speed of sound which are indirectly constrained by observations.
ER  -

@Article{10.21468/SciPostPhysCore.7.2.015,
	title={{Speed of sound in dense strong-interaction matter}},
	author={Jens Braun and Andreas Geißel and Benedikt Schallmo},
	journal={SciPost Phys. Core},
	volume={7},
	pages={015},
	year={2024},
	publisher={SciPost},
	doi={10.21468/SciPostPhysCore.7.2.015},
	url={https://scipost.org/10.21468/SciPostPhysCore.7.2.015},
}