# From lepton interactions to hadron and nuclear ones at high multiplicity

## TL;DR

This paper discusses models explaining high-multiplicity hadron production in particle collisions, confirming the fragmentation mechanism in vacuum and highlighting gluon recombination as a dominant process at high energies.

## Contribution

It introduces a gluon dominance model incorporating gluons to describe hadronization, emphasizing the recombination mechanism over fragmentation at high energies.

## Key findings

- Model accurately describes multiplicity data up to 200 GeV.
- Gluon recombination leads to increased hadron multiplicity at high energies.
- Soft photon excess confirmed experimentally at Nuclotron.

## Abstract

Multiplicity data up to 200 GeV in e+e- annihilation are described well by the two-stage model based on pQCD and suggested the phenomenological scheme of hadronization. This model confirms the fragmentation mechanism of hadronization (in vacuum). It allows to estimate mean multiplicity at 500 GeV and 1 TeV. Gluon dominance model is the modification of this model for the description of hadronic interactions. It was realised by an inclusion of gluons. It demonstrates very strong evidence of the recombination mechanism of hadronization. In this case, the mean multiplicity of hadrons formed from a single gluon grows with energy and it exceeds the corresponding values for lepton interactions. At the same time, the region of high multiplicity is stipulated for splitting of active gluons. The excess of soft photon yield is experimentally confirmed at Nuclotron (JINR) in the interactions of the 3.5A GeV/c deuteron and lithium beams with the carbon target.