Exotic meson decays in the environment with chiral imbalance

TL;DR

This paper explores how local parity breaking in high-energy heavy-ion collisions, caused by chiral imbalance, affects meson properties and decays, predicting observable signatures like photon polarization asymmetry.

Contribution

It extends the effective meson Lagrangian to include chiral imbalance effects, revealing exotic meson decays and novel electromagnetic formfactor features.

Findings

Exotic scalar meson decays due to $$ and $a_0$ mixing.

Photon polarization asymmetry from parity-odd formfactor.

Potential experimental signatures at LHC, RHIC, CBM FAIR, and NICA.

Abstract

An emergence 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. The effective meson lagrangian induced by QCD is extended to the medium with Chiral Imbalance and the properties of light scalar and pseudoscalar mesons ($\pi, a_0$) are analyzed. It is shown that exotic decays of scalar mesons arise as a result of mixing of $ \pi $ and $ a_0 $ vacuum states in the presence of chiral imbalance. The pion electromagnetic formfactor obtains an unusual parity-odd supplement which generates a photon polarization asymmetry in pion polarizability. We hope that the above pointed indications of LPB can be identified in experiments on LHC, RHIC, CBM FAIR and NICA accelerators.