A. A. Andrianov

Scalar mesons within QCD sum rules in the planar limit

The spectra of masses and decay constants for non‐strange scalar mesons in the energy range 0–2.5 GeV is analyzed. It is known from meson phenomenology that for given quantum numbers these spectra approximately follow linear trajectories with a universal slope. These facts can be understood in terms of an effective string description for QCD. For light meson states the trajectories deviate noticeably from the linear behavior. We investigate the possible corrections to the linear trajectories by matching two‐point correlators of quark currents to the Operator Product Expansion (OPE). We find that the allowed modifications to the linear Regge behavior must decrease rapidly with the principal quantum number. After fitting the lightest states in each channel and certain low‐energy constants the whole spectrum for scalar meson masses and residues is obtained in a satisfactory agreement with phenomenology.

QCD with Chiral Chemical Vector: Models Versus Lattices

A formation of Local Parity Breaking (LPB) in central heavy-ion collisions (HIC) at high energies is discussed. LPB in the fireball can be produced by a difference between the number densities of right- and left-handed chiral fermions (Chiral Imbalance) which is implemented by a chiral (axial) chemical potential. Based on the effective meson Lagrangian motivated by QCD in the chiral medium the properties of light scalar and pseudoscalar mesons (π, a0) are analyzed. It is found that exotic decays of scalar mesons arise as a result of mixing of π and a0 vacuum states in the presence of chiral imbalance. The pion electromagnetic formfactor obtains a parity-odd supplement which generates a photon polarization asymmetry in pion polarizability. We believe that the above-mentioned properties of LPB can be revealed in experiments on LHC, RHIC, CBM FAIR and NICA accelerators.

Searching for P- and CP-odd effects in heavy ion collisions

In this talk we will summarize the main results from our recent work concerning the possibility that a new metastable phase occurs in some heavy ion collisions (HIC). This phase would be characterized by the breaking of two characteristic symmetries of strong interactions; namely P and CP. We investigate the experimental consequences of parity breaking in such a situation and propose suitable observables to elucidate the presence this phenomenon.

On the effect of pion condensates on the spectrum of neutron stars

There is no precise theory describing the structure of neutron stars. However, inside such objects the baryon density is very high and a pion condensation may occur. These condensates, if they exist, might give a significant effect on a spectrum of neutron stars. We investigate this influence with a help of simplified model to give qualitative picture of the effect.

Extended supersymmetry and hidden symmetries in one-dimensional matrix quantum mechanics

We study properties of nonlinear supersymmetry algebras realized in the one-dimensional quantum mechanics of matrix systems. Supercharges of these algebras are differential operators of a finite order in derivatives. In special cases, there exist independent supercharges realizing an (extended) supersymmetry of the same super-Hamiltonian. The extended supersymmetry generates hidden symmetries of the super-Hamiltonian. Such symmetries have been found in models with (2×2)-matrix potentials.