Studies of extremely dense matter in heavy-ion collisions at J-PARC

We aim to study extremely dense matter in heavy-ion collisions at 1 - 19 AGeV/c at a future project of J-PARC (J-PARC-HI). We will search for the first order phase boundary and its critical end point in the QCD phase diagram. We also aim at studying the properties of dense matter related to neutron stars and neutron star mergers, in particular the equation of state (EOS). We expect to produce the world's highest rate of 10(11) Hz of heavy-ion beams, with ion species from p to U. We design spectrometers based on a large dipole magnet to measure hadrons, dimuons, and hypernuclei. We evaluate some of key performance of the spectrometers based on detailed simulations.