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

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.