Exotic meson decays and polarization asymmetry in hadron environment with chiral imbalance

A.E Putilova,A.V Iakubovich,V.A Andrianov,D Espriu,A.A Andrianov,V.E Volkova,V.A Matveev,D.G Levkov,Y.V Zhezher,V.A Rubakov

doi:10.1051/epjconf/201819105014

A.E Putilova, A.V Iakubovich + Show 8 more

Open Access

https://doi.org/10.1051/epjconf/201819105014

Copy DOI

Abstract

The possibility of the formation of a local parity breaking in a quark-hadron medium is described as a result of a violation of chiral symmetry, i.e, the difference between the average numbers of right and left -handing quarks in the fireball after HIC.The phenomenology of LPB in the fireball induces the introduction of a topological charge and, accordingly, a topological (chiral) chemical potential. Using the effective meson Lagrangian motivated by QCD in the chiral medium the properties of light scalar and pseudoscalar mesons are analyzed. It is establish 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 consider that the above-mentioned properties of LPB can be revealed in experiments on LHC, RHIC, CBM FAIR and NICA accelerators.

Highlights

We are going to investigate new properties of the light mesons in a chiral imbalance medium
The possibility of the formation of a local parity breaking in a quark-hadron medium is described as a result of a violation of chiral symmetry, i.e, the difference between the average numbers of right and left -handing quarks in the fireball after heavy-ion collisions (HIC).The phenomenology of Local Parity Breaking (LPB) in the fireball induces the introduction of a topological charge and, a topological chemical potential
It is establish that exotic decays of scalar mesons arise as a result of mixing of π and a0 vacuum states in the presence of chiral imbalance

Summary

Motivation and aims

To describe in fireball such a quark-hadron matter with chiral imbalance we must introduce the axial/chiral chemical potential [1]. There are some experimental indications of an abnormal dilepton excess in the range of low invariant masses and rapidities, and moderate values of the transverse momenta [2], which can be partially thought of as a result of LPB in the medium (the details can be found in [3]). We are going to investigate new properties of the light mesons in a chiral imbalance medium. The work includes the following items: finding of the modified vertices of meson decays; obtaining of the decay widths dependence on energy and chiral chemical potential; consideration of a pion-photon scattering in chiral medium; definition and calculation an expression for the polarization asymmetry in a pion-photon scattering

The chiral imbalance in medium and axial chemical potential

Sigma meson model and Wess-Zumino-Witten action in chiral medium

P-odd vertices for light mesons

Pion-photon scattering and asymmetry in photon polarizations

Conclusions and outlook