Production of Neutral Pions and Eta-mesons in pp Collisions Measured with ALICE

TL;DR

This paper reports measurements of neutral pions and eta mesons in proton-proton collisions at various energies using ALICE, comparing results with QCD predictions and exploring scaling behaviors.

Contribution

It provides the first detailed measurements of pi0 and eta mesons at multiple energies with ALICE, testing perturbative QCD and mT scaling at high energies.

Findings

NLO pQCD describes spectra at 0.9 TeV but overestimates at higher energies.

Eta/pi0 ratio is consistent with mT scaling at 2.76 TeV.

Possible violation of mT scaling observed at 7 TeV.

Abstract

Invariant cross sections for neutral pions and eta mesons in pp collisions at sqrt(s) = 0.9, 2.76, and 7 TeV were measured by the ALICE detector at the Large Hadron Collider. Next-to-leading order (NLO) perturbative QCD calculations describe the pi0 and eta spectra at 0.9 TeV, but overestimate the measured cross sections at 2.76 TeV and 7 TeV. The measured eta/pi0 ratio is consistent with mT scaling at 2.76 TeV. At 7 TeV indications for a violation of mT scaling were found.