Identified hadron production in pp collisions measured with ALICE

The production of identified hadrons in proton-proton collisions is frequently studied as a reference for the investigation of the strongly-interacting medium created in heavy-ion collisions. In addition, at LHC energies measurements in pp and p–Pb collisions as a function of the event multiplicity have shown some features reminiscent of those related to collective effects in Pb–Pb collisions. Thanks to its excellent PID capabilities and p (Τ) coverage, the ALICE detector offers a unique opportunity for the measurement of p (Τ) spectra, integrated yields (dN/dy) and mean transverse momenta (〈p (Τ)〉) of identified light-flavour hadrons at midrapidity over a wide p (Τ) range. In this contribution, results on π, K, p, ${{\rm{K}}}_{{\rm{S}}}^{0}$, Λ, Ξ, Ω and K(*0) as a function of multiplicity in pp collisions at $\sqrt{s}=7\ \mathrm{TeV}$ are presented. The results are compared with those measured in p–Pb and Pb–Pb collisions. A similar evolution of the spectral shape, the p (Τ)-differential particle ratios and the integrated yield ratios with the charged particle multiplicity in both small and large systems is observed. The production rates of strange hadrons in pp collisions increase more than those of non-strange particles, showing an enhancement pattern with multiplicity which is remarkably similar to the one measured in p–Pb collisions. In addition, results on the production of light flavour hadrons in pp collisions at $\sqrt{s}=13\ \mathrm{TeV}$, the highest centre-of-mass energy reached so far in the laboratory, are also presented and the behaviour observed as a function of $\sqrt{s}$ are discussed.