Spin asymmetries in jet-hyperon production at LHC

TL;DR

This paper proposes a new Lambda hyperon polarization observable in proton-proton collisions at the LHC, which can reveal insights into spin asymmetries, fragmentation mechanisms, and the universality of TMD functions.

Contribution

It introduces a novel Lambda polarization observable arising from the Sivers effect in fragmentation, applicable at midrapidity in high-energy collider experiments.

Findings

Potential for large polarization signals at midrapidity

Ability to test color flow dependence of spin asymmetries

Insights into the universality of TMD fragmentation functions

Abstract

We consider polarized Lambda hyperon production in proton-proton scattering, p p -> (\Lambda^\uparrow jet) jet X, in the kinematical region of the LHC experiments, in particular the ALICE experiment. We present a new Lambda polarization observable that arises from the Sivers effect in the fragmentation process. It can be large even at midrapidity and therefore, is of interest for high energy hadron collider experiments. Apart from its potential to shed light on the mechanisms behind the phenomenon of Lambda polarization arising in unpolarized hadronic collisions, the new observable in principle also allows to test the possible color flow dependence of single spin asymmetries and the (non)universality of transverse momentum dependent fragmentation functions.