Spontaneous CP violation in quark scattering from QCD Z(3) interfaces

TL;DR

This paper investigates spontaneous CP violation during quark scattering from QCD Z(3) domain walls, revealing potential effects on heavy-ion collisions and early universe cosmology through gauge field profiles and quark reflection calculations.

Contribution

It introduces a novel mechanism of spontaneous CP violation arising from Z(3) gauge field profiles and analyzes its implications for quark scattering and cosmological phenomena.

Findings

CP violation occurs from nontrivial gauge field profiles across Z(3) interfaces.

It predicts baryon enhancement at high transverse momentum in heavy-ion collisions.

It suggests additional J/ψ suppression due to CP violation effects.

Abstract

In this paper, we explore the possibility of spontaneous CP violation in the scattering of quarks and anti-quarks from QCD Z(3) domain walls. The CP violation here arises from the nontrivial profile of the background gauge field $(A_{0})$ between different Z(3) vacua. We calculate the spatial variation of $A_{0}$ across the Z(3) interface from the profile of the Polyakov loop $L(\vec{x})$ for the Z(3) interface and calculate the reflection of quarks and antiquarks using the Dirac equation. This spontaneous CP violation has interesting consequences for the relativistic heavy-ion collision experiments, such as baryon enhancement at high $P_{T}$. It also acts as a source of additional J/$\psi$ suppression. We also discuss its implications for the early universe.