Soft QCD theory

TL;DR

This paper reviews phenomenological models and mechanisms used in Soft QCD to describe non-perturbative phenomena like hadronization and baryon production, highlighting recent experimental observations at the LHC.

Contribution

It discusses new models and mechanisms such as junction reconnection, ropes, and the core-corona approach to address non-universal hadronization features at the LHC.

Findings

Observation of charm and bottom baryon enhancement at the LHC

Detection of bottom baryon asymmetry in pp collisions

Strangeness enhancement phenomena

Abstract

Soft QCD is beyond perturbative control, and therefore phenomenological models have to be developed. These are implemented and combined within event generators. Typical aspects considered are multiparton interactions, colour reconnection, and hadronization. Of special interest are non-universal features of hadronization at the LHC, such as the recently observed enhancement of charm and bottom baryons, and the bottom baryon asymmetry, as well as the some years earlier observed strangeness enhancement. Several new production mechanisms, such as junction reconnection, ropes and shove, have been proposed to address some of these issues. Alternatively, an admixture of a quark--gluon plasma component also in pp collisions is introduced in the core--corona approach.