Wess-Zumino-Witten action and photons from the Chiral Magnetic Effect

We revisit the Chiral Magnetic Effect (CME) using the chiral Lagrangian. We demonstrate that the electric-current formula of the CME is derived immediately from the contact part of the Wess-Zumino-Witten action. This implies that the CME could be, if observed, a signature for the local parity violation, but a direct evidence for neither quark deconfinement nor chiral restoration. We also discuss the reverse Chiral Magnetic Primakoff Effect, i.e. the real photon production through the vertex associated with the CME, which is kinematically possible for space-time inhomogeneous configurations of magnetic fields and the strong theta angle. We make a qualitative estimate for the photon yield to find that it comparable to the thermal photon.Comment: 5 pages, 1 figure; some discussions refine

QCD θ\theta-vacua from the chiral limit to the quenched limit

We investigate the dependence of the QCD vacuum structure on the $\theta$-angle and quark mass, using the Di-Vecchia--Veneziano model. Although the Di-Vecchia--Veneziano model is a chiral effective model, it contains the topological properties of the pure Yang--Mills theory. It is shown that within this model, the ground state energies for all $\theta$ are continuous functions of quark mass from the chiral limit to the quenched limit, even including the first order phase transition at $\theta = \pi$. Based on this effective model, we discuss (i) how the ground state depends on quark mass, and (ii) why the phase transition at $\theta = \pi$ is present both in the chiral and quenched limit. In order to analyze the relation between quark mass and the $\theta$-vacua, we calculate the chiral condensate as a function of quark mass. Also, considering the presence of the innate metastable states included in the QCD $\theta$-vacuum, we also give a unified understanding of the phase transitions at $\theta = \pi$ in the chiral and quenched limit.Comment: 18 pages, 8 figure

Nonlinear chiral kinetic theory

From quantum field theory, we derive the chiral kinetic theory involving nonlinear quantum corrections coupled with spacetime-dependent electromagnetic fields and fluid velocity gradients. An equilibrium Wigner function determined by the the kinetic equation verifies the nondissipativeness of the charge induced by the magneto-vortical coupling. We reveal that this nonlinear chiral kinetic theory is consistent with the one-loop Euler--Heisenberg effective theory, indicating an indirect evidence of the trace anomaly in the kinetic theory. We also argue a potential issue on the regularization, and demonstrate the availability of the point-splitting regularization in the nonlinear chiral kinetic theory.Comment: 33 page

Deconfinement transition in the revolving bag model

Based on the bag model, we revisit the deconfinement phase transition under rotation. On top of the usual rotational energy for noninteracting particles, we perturbatively analyze the revolution effect of the hadron bag, i.e., of the potential confining quarks. The revolution effect can be phenomenologically translated into the rotational correction to the QCD vacuum energy or the gluon condensate. We demonstrate that if the revolution effect is (is not) taken into account, the transition temperature increases (decreases) as the angular velocity increased. The `revolving bag model' provides a feasible explanation of the recent lattice simulations, contrary to effective models, showing that rotation favors the confined phase.Comment: 6 page

回転する相対論的システムにおけるカイラル対称性と真空構造

学位の種別: 課程博士審査委員会委員 : （主査）東京大学准教授 安東 正樹, 東京大学准教授 森松 治, 東京大学教授 加藤 光裕, 東京大学准教授 桂 法称, 東京大学准教授 小沢 恭一郎University of Tokyo(東京大学

回転する相対論的システムにおけるカイラル対称性と真空構造

学位の種別: 課程博士審査委員会委員 : （主査）東京大学准教授 安東 正樹, 東京大学准教授 森松 治, 東京大学教授 加藤 光裕, 東京大学准教授 桂 法称, 東京大学准教授 小沢 恭一郎University of Tokyo(東京大学