@article{oai:nagoya.repo.nii.ac.jp:00026367,
 author = {Takeda, Yusuke and Kim, Youngman and Harada, Masayasu},
 issue = {6},
 journal = {Physical Review C},
 month = {Jun},
 note = {We study the phase structure of dense hadronic matter including Δ(1232) as well as N(939) based on the parity partner structure, where the baryons have their chiral partners with a certain amount of chiral invariant masses. We show that, in symmetric matter, Δ enters into matter in the density region of about one to four times normal nuclear matter density, ρB∼1−4ρ0. The onset density of Δ matter depends on the chiral invariant mass of Δ,mΔ0: As mΔ0 increases, the onset density becomes bigger. The stable Δ-nucleon matter is realized for ρB≳1.5ρ0, i.e., the phase transition from nuclear matter to Δ-nucleon matter is of first order for small mΔ0, and it is of second order for large mΔ0. We find that, associated with the phase transition, the chiral condensate changes very rapidly; i.e., the chiral symmetry restoration is accelerated by Δ matter. As a result of the accelerations, there appear N^∗(1535) and Δ(1700), which are the chiral partners to N(939) and Δ(1232), in high-density matter, signaling the partial chiral symmetry restoration. Furthermore, we find that complete chiral symmetry restoration itself is delayed by Δ matter. We also calculate the effective masses, pressure, and symmetry energy to study how the transition to Δ matter affects such physical quantities. We observe that the physical quantities change drastically at the transition density.},
 title = {Catalysis of partial chiral symmetry restoration by Δ matter},
 volume = {97},
 year = {2018}
}