Studies of nuclear equation of state with the HIRFL-CSR external-target experiment

The Heavy Ion Research Facility in Lanzhou-Cooling Storage Ring (HIRFL-CSR) external-target experiment (CEE) under construction is expected to provide novel opportunities for the studies of the thermodynamic properties of nuclear matter, in particular the nuclear matter equation of state (nEOS), with heavy ion collisions at a few hundreds MeV/u beam energies. Based on Geant 4 packages, the simulations of the detector responses to the collision events generated using transport model are conducted. The overall performance of CEE, including the geometric coverage, the momentum resolution of tracks and the particle identification ability has been investigated. Various observables proposed to probe the nEOS, such as the production of light clusters, ^3H/^3He yield ratio, radial flow, π ^-/π ^+ yield ratio and neutral kaon yields, have been reconstructed. The feasibility of studying nEOS beyond the saturation density via the aforementioned observables to be measured with CEE has been demonstrated by using the ultra relativistic quantum molecular dynamics (UrQMD) simulation data.