  A new transport code "DaeJeon Boltzmann-Uehling-Uhlenbeck (DJBUU)" had been
developed and enables to describe the dynamics of heavy-ion collisions in
low-energy region. To confirm the validity of the new code, we first calculate
Au + Au collisions at Ebeam = 100 and 400A MeV and also perform the box
calculation to check the detail of collisions and Pauli blocking without
mean-field potential as suggested by the Transport Code Comparison Project.
After confirming the validity of new transport code, we study low-energy
heavy-ion collisions with an extended parity doublet model. Since the
distinctive feature of the parity doublet model is the existence of the chiral
invariant mass that contributes to the nucleon mass, we investigate how
physical quantities depend on the chiral invariant mass in heavy ion collisions
at low energies. For this, we calculate physical quantities such as the
effective nucleon mass in central collisions and transverse flow in
semi-central collisions of Au + Au at Ebeam = 400A MeV with different values of
the chiral invariant masses.
