Neutral pion and $\eta$ meson production in proton-proton collisions at $\sqrt{s}=0.9$ TeV and $\sqrt{s}=7$ TeV

TL;DR

This paper reports the first measurements of inclusive neutral pion and eta meson production cross sections in proton-proton collisions at two different energies, comparing results with theoretical QCD predictions.

Contribution

It provides new experimental data on meson production at LHC energies and evaluates the accuracy of perturbative QCD calculations against these measurements.

Findings

NLO pQCD overestimates meson yields at 7 TeV

Measurements agree with pQCD at 0.9 TeV

Eta/pi0 ratio matches theoretical predictions at 7 TeV

Abstract

The first measurements of the invariant differential cross sections of inclusive $\pi^0$ and $\eta$ meson production at mid-rapidity in proton-proton collisions at $\sqrt{s}=0.9$ TeV and $\sqrt{s}=7$ TeV are reported. The $\pi^0$ measurement covers the ranges $0.4<p_T<7$ GeV/$c$ and $0.3<p_T<25$ GeV/$c$ for these two energies, respectively. The production of $\eta$ mesons was measured at $\sqrt{s}=7$ TeV in the range $0.4<p_T<15$ GeV/$c$. Next-to-Leading Order perturbative QCD calculations, which are consistent with the $\pi^0$ spectrum at $\sqrt{s}=0.9$ TeV, overestimate those of $\pi^0$ and $\eta$ mesons at $\sqrt{s}=7$ TeV, but agree with the measured $\eta/\pi^0$ ratio at $\sqrt{s}=7$ TeV.