A project to study high-density nuclear matter using heavy ion collisions in a beam energy range ... more A project to study high-density nuclear matter using heavy ion collisions in a beam energy range of few GeV is being prepared at J-PARC. The goal of the project is to perform experiments with beam energies of 1-12 AGeV/c and the collision rate of 1011 Hz. The project is divided into two phases. For the first stage, measurements with a limited beam intensity will be performed with upgraded spectrometer of an on-going experiment. Full performance will be implemented at the second phase to study in detail the high density matter and light hypernuclei. Feasibility of measurements for both phases are being evaluated.
Results on proton and Λ flow, calculated with the UrQMD model that incorporates different realist... more Results on proton and Λ flow, calculated with the UrQMD model that incorporates different realistic density dependent equations of state, are presented. It is shown that the proton and hyperon flow shows sensitivity to the equation of state and especially to the appearance of a phase transition at densities below 4n0. Even though qualitatively hyperons and protons exhibit the same beam energy dependence of the flow, the quantitative results are different. In this context it is suggested that the hyperon measurements can be used to study the density dependence of the hyperon interaction in high density QCD matter.
We examine the Λ potential from the chiral effective field theory (χEFT) via the Λ directed flow ... more We examine the Λ potential from the chiral effective field theory (χEFT) via the Λ directed flow from heavy-ion collisions. We implement the Λ potential obtained from the χEFT in a vector potential version of relativistic quantum molecular dynamics. We find that the Λ potentials obtained from the χEFT assuming weak momentum dependence reproduce the Λ directed flow measured by the STAR collaboration in the Beam Energy Scan program. While the Λ directed flow is not very sensitive to the density dependence of the potential, the directed flow at large rapidities is susceptible to the momentum dependence. Thus understanding the directed flow of hyperons in a wide range of beam energy and rapidity is helpful in understanding hyperon potentials in dense matter.
It is shown that the initial compression in central heavy ion collisions at beam energies of $$E_... more It is shown that the initial compression in central heavy ion collisions at beam energies of $$E_{\mathrm {lab}}=1-10A$$ E lab = 1 - 10 A GeV depends dominantly on the underlying equation of state and only marginally on the model used for the dynamical description. To do so, a procedure to incorporate any equation of state in the UrQMD transport model is introduced. In particular we compare the baryon density, temperature and pressure evolution as well as produced entropy in a relativistic ideal hydrodynamics approach and the UrQMD transport model, where the same equation of state is used in both approaches. Not only is the compression similar if the same equation of state is used in either dynamical model, but it also strongly depends on the actual equation of state. These results indicate that the equation of state can be studied with observables which are sensitive to the initial compression phase and maximum compression achieved in heavy ion collisions at these beam energies.
A project to study high-density nuclear matter using heavy ion collisions in a beam energy range ... more A project to study high-density nuclear matter using heavy ion collisions in a beam energy range of few GeV is being prepared at J-PARC. The goal of the project is to perform experiments with beam energies of 1-12 AGeV/c and the collision rate of 1011 Hz. The project is divided into two phases. For the first stage, measurements with a limited beam intensity will be performed with upgraded spectrometer of an on-going experiment. Full performance will be implemented at the second phase to study in detail the high density matter and light hypernuclei. Feasibility of measurements for both phases are being evaluated.
Results on proton and Λ flow, calculated with the UrQMD model that incorporates different realist... more Results on proton and Λ flow, calculated with the UrQMD model that incorporates different realistic density dependent equations of state, are presented. It is shown that the proton and hyperon flow shows sensitivity to the equation of state and especially to the appearance of a phase transition at densities below 4n0. Even though qualitatively hyperons and protons exhibit the same beam energy dependence of the flow, the quantitative results are different. In this context it is suggested that the hyperon measurements can be used to study the density dependence of the hyperon interaction in high density QCD matter.
We examine the Λ potential from the chiral effective field theory (χEFT) via the Λ directed flow ... more We examine the Λ potential from the chiral effective field theory (χEFT) via the Λ directed flow from heavy-ion collisions. We implement the Λ potential obtained from the χEFT in a vector potential version of relativistic quantum molecular dynamics. We find that the Λ potentials obtained from the χEFT assuming weak momentum dependence reproduce the Λ directed flow measured by the STAR collaboration in the Beam Energy Scan program. While the Λ directed flow is not very sensitive to the density dependence of the potential, the directed flow at large rapidities is susceptible to the momentum dependence. Thus understanding the directed flow of hyperons in a wide range of beam energy and rapidity is helpful in understanding hyperon potentials in dense matter.
It is shown that the initial compression in central heavy ion collisions at beam energies of $$E_... more It is shown that the initial compression in central heavy ion collisions at beam energies of $$E_{\mathrm {lab}}=1-10A$$ E lab = 1 - 10 A GeV depends dominantly on the underlying equation of state and only marginally on the model used for the dynamical description. To do so, a procedure to incorporate any equation of state in the UrQMD transport model is introduced. In particular we compare the baryon density, temperature and pressure evolution as well as produced entropy in a relativistic ideal hydrodynamics approach and the UrQMD transport model, where the same equation of state is used in both approaches. Not only is the compression similar if the same equation of state is used in either dynamical model, but it also strongly depends on the actual equation of state. These results indicate that the equation of state can be studied with observables which are sensitive to the initial compression phase and maximum compression achieved in heavy ion collisions at these beam energies.
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