Experimental overview on the QCD critical point search and nuclear matter phase diagram

Understanding the QCD phase structure and nuclear matter properties at high baryon density regions remains one central focus of heavy-ion programs worldwide. In this talk, I will review experimental measurements from low energy heavy ion experiments, with an emphasis on recent results from the Beam Energy Scan phase-II (BES-II) program at RHIC. These measurements include identified particle yield and their collectivity including hadrons and nuclei containing strange flavor to benchmark freezeout thermal properties and to gain insight of the Equation-of-State, dilepton yield towards the understanding of medium chiral properties and phase transition nature, as well as baryon correlations and fluctuations in order to search for the critical point induced signal etc. Further experimental perspectives from the BES-II results will be discussed. In the end, I will briefly discuss physics programs and discovery potentials at future facilities aiming for QCD phase structure at high density regions.