Exploring QCD phase structure: Lattice QCD approach and its application to Experiments

Atsushi Nakamura (Far Eastern Federal University, Russia and Theoretical Research Division, Nishina Center, RIKEN, Japan and Research Center for Nuclear Physics (RCNP), Osaka University, Japan)

As gradually recognized, heavy ion collision at NICA and J-PARC energy regions can play an important role for understanding QCD at finite baryon density. This will be demonstrated in this talk by analysis of baryon (proton) number fluctuation data at RHIC energy scan experiments. For many years, the first principle calculation at finite density regions was believed to be impossible because of the sign problem. Our group has developed lattice QCD approach to overcome this difficulty. I believe that we are in front of the new era in which we can explore finite density QCD by experiments and numerical simulations.