$\Lambda$ and $\bar{\Lambda}$ spin interaction with meson fields generated by the baryon current in high energy nuclear collisions

TL;DR

This paper introduces a dynamical mechanism where hyperon and antihyperon spins interact with baryon current vorticity via meson exchange, potentially explaining polarization differences observed in high energy nuclear collisions.

Contribution

It presents a novel interaction model mediated by vector and scalar mesons that accounts for hyperon polarization phenomena in nuclear collisions.

Findings

Proposes a spin-vorticity interaction mechanism mediated by mesons.

Explains polarization differences of hyperons and antihyperons observed experimentally.

Connects meson-baryon couplings to hypernuclei binding energies and neutron star hyperon abundance.

Abstract

We propose a dynamical mechanism which provides an interaction between the spins of hyperons and antihyperons and the vorticity of the baryon current in noncentral high energy nuclear collisions. The interaction is mediated by massive vector and scalar bosons which is well known to describe the nuclear spin-orbit force. It follows from the Foldy-Wouthuysen transformation and leads to a strong-interaction Zeeman effect. The interaction may explain the difference in polarizations of $\Lambda$ and $\bar{\Lambda}$ hyperons as measured by the STAR Collaboration at the BNL Relativistic Heavy Ion Collider. The signs and magnitudes of the meson-baryon couplings are closely connected to the binding energies of hypernuclei and to the abundance of hyperons in neutron stars.