New physics opportunities at high baryon densities

Beam energy scan programs are carried out at RHIC and SPS with the goals of finding signatures for the disappearance of the QGP, a QCD phase transition, and for a critical point. In this paper an overview of various observables studied by STAR, PHENIX, and NA60 to identify those structures in the QCD phase diagram are discussed. Furthermore, an outlook on the Beam Energy Scan phase II program at RHIC, which is anticipated for the years 2018–2019, is given.