ALICE pp physics programme

TL;DR

The ALICE experiment at CERN-LHC studies proton-proton collisions, focusing on bulk observables like charged hadron multiplicity and strange hadron production, providing insights into soft particle production mechanisms at unprecedented energies.

Contribution

This paper presents detailed measurements of global event characteristics and strange hadron production in pp collisions, leveraging ALICE's unique low transverse momentum particle identification capabilities.

Findings

Charged hadron multiplicity distributions measured at high energies.

Strange hadron yields and spectra obtained down to very low transverse momentum.

Enhanced understanding of soft particle production mechanisms in proton-proton collisions.

Abstract

The physics programme of the ALICE experiment at CERN-LHC comprises besides studies of high-energy heavy-ion collisions measurements of proton-proton interactions at unprecedented energies, too. This paper focuses on the global event characterisation in terms of the multiplicity distribution of charged hadrons and mean transverse momentum. These bulk observables become accessible because the detector features excellent track reconstruction, especially at low transverse momenta. The measurement of strange hadrons is of particular interest since the strange-particle phase-space was found to be suppressed beyond canonical reduction at lower center-of-mass energies and the production mechanism of soft particles is not yet fully understood. Here we benefit in particular from particle identification down to very low transverse momentum, i.e. 100 - 300 MeV/c, giving access to spectra and integrated yields of identified hadrons. Equipped with these features, ALICE will play a complementary role w.r.t. other LHC experiments. New interest in the soft part of pp collisions arose recently and new insights in the physics of the underlying event are expected from both, theory and experiment.