Phase diagram and dualities of dense baryonic matter with chiral imbalance
Seminars
Seminar on Theory of hadronic matter under extreme conditions
Date and Time: Wednesday, 31 October 2018, at 4:00 PM
Venue: Blokhintsev Hall (4th floor), Bogoliubov Laboratory of Theoretical Physics
Seminar topic: “Phase diagram and dualities of dense baryonic matter with chiral imbalance”
Speaker: Roman Zhokhov (IHEP, Protvino)
Abstract:
In this talk the phase structure of the dense quark matter has been investigated in the presence of baryon μB, isospin μI, chiral μ5 and chiral isospin μI5 chemical potentials in the framework of Nambu-Jona-Lasinio model with two quark flavors. It has been shown that in the large-Nc limit ( Nc is the number of colors of quarks) there exist duality correspondences at the phase portrait. The first one is a duality between the chiral symmetry breaking and the charged pion condensation phenomena. And there are two other dualities that hold only for chiral symmetry breaking and charged pion condensation phenomena separately. For example, we have shown that charged pion condensation does not feel the difference between chiral and isospin imbalances of the medium. The duality between the chiral symmetry breaking and the charged pion condensation phases has been established for the first time in low-dimensional toy model for QCD then it has been checked to take place in a more realistic effective model for QCD. One of the key conclusions of our studies is the fact that chiral imbalance generates charged pion condensation in dense baryonic/quark matter. It was also shown that our results in particular cases are consistent with the simulation of lattice QCD, which is possible for isospin and chiral chemical potentials. Moreover, in a number of works, catalysis of chiral symmetry breaking by chiral imbalance was predicted, but there were also works that predict the opposite effect. After lattice calculations that confirmed the effect of catalysis of chiral symmetry breaking, we can, of course, say that the problem has been solved, but it would be interesting to find out the reasons for the discrepancy between the results of effective models. We have made a small step in this direction and showed that, based on the dualities and the well-studied properties of the phase structure of QCD with only isotopic imbalance, one can conclude that there should be an effect of catalysis of chiral symmetry breaking. It was also shown that the fact that the chiral imbalance generates the phenomenon of charged pion condensation in dense baryonic/quark matter also remains true for the case of charge neutral matter, which is interesting in the context of the astrophysics of neutron stars. It is known that chiral imbalance can occur in high energy experiments on the collision of heavy ions, due to temperature and sphaleron transitions. Our studies show that different types of chiral imbalance can occur in the cores of neutron stars or in heavy ion experiments where large baryon densities can be reached, due to another phenomenon – the so-called chiral separation effect (although there were references to this possibility, we explored it in more details).