Speaker
Description
In the core of neutron stars, extreme gravitational fields probe the stiffness of matter at very large densities. Recent neutron-star observations indicate that ultradense matter must be stiffer than previously thought, with the speed of sound potentially rising well above its asymptotic conformal limit of $1/\sqrt{3}$ [1]. Nonetheless, the implications of this large speed-of-sound peak for the phenomenology of cold and dense QCD are far from being understood. In this work, we address the general physics requirements that must be fulfilled for the speed of sound of cold and dense QCD to have a peak surpassing the conformal limit, and propose a generic mechanism to explain this feature [2]. We build a model realization of this mechanism and explore its possible connection to the formation of diquarks, as well as the transition to quark or quarkyonic matter. Our results suggest that diquark interactions might play a pivotal role in the equation of state of highly compressed matter.
[1] Christian Drischler, Sophia Han, James M. Lattimer, Sanjay Reddy, Tianqi Zhao, Phys. Rev. C 103, 045808 (2021)
[2] Maurício Hippert, Eduardo S. Fraga, Jorge Noronha, Phys. Rev. D 104, 034011 (2021)
