Identified particles in pp and Pb-Pb collisions at LHC energies with the ALICE detector

TL;DR

This paper reviews particle identification techniques used by ALICE at LHC and summarizes results on identified particle spectra in pp and Pb-Pb collisions, highlighting energy dependence, particle ratios, and comparisons to models.

Contribution

It provides a comprehensive overview of particle identification methods and presents new measurements of particle spectra and ratios at different energies and collision centralities.

Findings

Energy dependence of spectral shapes in pp collisions

Baryon/meson ratio $\\Lambda/K^0_S$ varies with centrality

Particle spectra evolution consistent with thermal and hydrodynamical models

Abstract

The ALICE experiment has been taking data since 2009, with proton and lead beams. In this paper, the different particle identification techniques used by the experiment are briefly reviewed. The current results on identified particle spectra in pp collisions at $\sqrt{s} = 900 \mathrm{GeV}$ and 7 TeV, and in Pb-Pb collisions at $\snn = 2.76 \mathrm{TeV}$ are summarized. In particular, the energy dependence of the spectral shapes and particle ratios in pp collisions is discussed and the results are compared to previous experiments and commonly used Monte Carlo models. The baryon/meson ratio $\Lambda/K^0_S$ is studied in Pb-Pb collisions as a function of transverse momentum and centrality, and it is compared to previous results. The evolution of the particle spectra in Pb-Pb with collision centrality is compared to measurements at lower energies and discussed in the context of thermal and hydrodynamical models.