Speaker
Description
The strongest force in nature binds quarks and gluons into hadrons, confining them under ordinary conditions. Collisions of heavy nuclei at the Relativistic Heavy Ion Collider (RHIC) just ended in 2026 after 25 years of running. These collisions momentarily liberated confined hadrons into a quark–gluon plasma phase—a short-lived droplet of Quantum Chromodynamics (QCD) matter that flows with nearly perfect fluidity. The discovery of the quark-gluon plasma pushed our understanding of relativistic fluids to its limits, driving theoretical developments with far-reaching consequences.
At high-energies the transition from quarks and gluons into hadrons is known to be a cross-over from first-principles lattice QCD calculations. However, at low-energies and large baryon densities a critical point is anticipated which would be the first one discovered within a fundamental theory of nature. The RHIC Beam Energy Scan has opened rare experimental access to the QCD phase diagram at high baryon density, including possible signatures of a critical point with implications for neutron-star matter. Here I will review the latest findings from experiments, the theoretical efforts to locate the QCD critical point, and future implications that connect to neutron star observations and gravitational waves.