Chiral imbalance in QCD
1 Department of Physics, Saint Petersburg State University, Universitetskaya nab. 7/9, Saint Petersburg 199034, Russia
2 Institute of Cosmos Sciences (ICCUB), University of Barcelona, Martí i Franquès, 1, 08028 Barcelona, Spain
Published online: 27 March 2017
The chiral imbalance (ChI) is given by a difference between the numbers of RH and LH quarks which may occur in the fireball after heavy ion collision. To characterize it adiabatically a quark chiral (axial) chemical potential must be introduced taking into account emergence of a ChI in such a phase. In this report the phenomenology of formation of Local spatial Parity Breaking (LPB) in the hot and dense baryon matter is discussed and its simulation within a number of QCD-inspired models is outlined. The appearance of new states in the spectra of scalar, pseudoscalar and vector particles in such a matter is elucidated. In particular, from the effective vector meson theory in the presence of Chern-Simons interaction it is demonstrated that the spectrum of massive vector mesons splits into three polarization components with different effective masses. The asymmetry in production of longitudinally and transversely polarized states of ρ and ω mesons for various values of the dilepton invariant mass can serve as a characteristic indication of the LPB in PHENIX, STAR and ALICE experiments.
© The Authors, published by EDP Sciences, 2017
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