Production of pions, kaons and protons in pp collisions at $\sqrt{s}=900$ GeV with ALICE at the LHC

TL;DR

This paper reports on the measurement of pion, kaon, and proton production in proton-proton collisions at 900 GeV using the ALICE detector, combining multiple identification methods to cover a broad momentum range and comparing results with theoretical models.

Contribution

It provides detailed spectra of identified hadrons in pp collisions at 900 GeV, utilizing multiple particle identification techniques and comparing results with QCD-inspired models.

Findings

Spectra cover $p_T$ from 100 MeV/c to 2.5 GeV/c.

QCD-inspired models poorly describe the measured spectra.

Total yields and mean $p_T$ are consistent with previous measurements.

Abstract

The production of $\pi^+$, $\pi^-$, $K^+$, $K^-$, p, and pbar at mid-rapidity has been measured in proton-proton collisions at $\sqrt{s} = 900$ GeV with the ALICE detector. Particle identification is performed using the specific energy loss in the inner tracking silicon detector and the time projection chamber. In addition, time-of-flight information is used to identify hadrons at higher momenta. Finally, the distinctive kink topology of the weak decay of charged kaons is used for an alternative measurement of the kaon transverse momentum ($p_{\rm T}$) spectra. Since these various particle identification tools give the best separation capabilities over different momentum ranges, the results are combined to extract spectra from $p_{\rm T}$ = 100 MeV/$c$ to 2.5 GeV/$c$. The measured spectra are further compared with QCD-inspired models which yield a poor description. The total yields and the mean $p_{\rm T}$ are compared with previous measurements, and the trends as a function of collision energy are discussed.