Double Parton Scattering, Multi-Parton Interactions, underlying event and identified hadrons: summary of recent results

TL;DR

This paper reviews recent experimental results from LHC on Double-Parton Scattering, Multi-Parton Interactions, and underlying event modeling, highlighting new insights into hadron production and correlations with event multiplicity.

Contribution

It provides a comprehensive summary of recent LHC findings on DPS, MPI, and underlying event, and discusses their integration into Monte Carlo models and implications for hadron spectra.

Findings

Robust evidence for DPS at LHC energies.

Enhanced understanding of MPI and underlying event modeling.

Identified hadron spectra show correlations with event multiplicity.

Abstract

Recent results related to Double-Parton Scattering (DPS) and Multi-Parton Interactions (MPI) from the LHC experiments (ALICE, ATLAS, CMS and LHCb) are reviewed and discussed together with a brief overview of relevant literature. The robust evidence collected for DPS in different channels at LHC energies is complemented by an increasing understanding of our description of MPI in high energy collisions and the corresponding modelling of the underlying event (UE) in hadronic interactions. Potential new results expected during Run 2 at the LHC are also anticipated. The relation and the interplay between the relevant observables for DPS, MPI and UE analyses are discussed presenting recent attempts to bring together their description in a single Monte Carlo tune. Identified hadron spectra at the LHC have been now measured by all collaborations and results are reviewed with an emphasis on strangeness production and baryon/meson ratio. The data collected during Run 1 at the LHC with different collision systems (pp, p-Pb, Pb-Pb) show that several particle production features appear to be more correlated with the event multiplicity than the collision system itself.