Lambda Polarization in Peripheral Heavy Ion Collisions

TL;DR

This paper predicts Lambda hyperon polarization in peripheral heavy ion collisions, linking it to local thermodynamic properties, and suggests experimental detection is feasible through targeted measurements.

Contribution

It introduces a novel prediction of Lambda polarization based on thermodynamic equilibrium assumptions in ultrarelativistic collisions.

Findings

Polarization proportional to curl of inverse temperature four-vector

Maximum polarization for particles with moderate momentum on the reaction plane

Polarization magnitude of a few percent

Abstract

We predict the polarization of Lambda and antiLambda hyperons in peripheral heavy ion collisions at ultrarelativistic energy, based on the assumption of local thermodynamical equilibrium at freeze-out. The polarization vector is proportional to the curl of the inverse temperature four-vector field and its length, of the order of percents, is maximal for particle with moderately high momentum lying on the reaction plane. A selective measurement of these particles could make Lambda polarization detectable.