Production of $\omega$ mesons in pp collisions at $\sqrt{s}$ = 7 TeV

TL;DR

This paper reports the measurement of inclusive omega meson production in proton-proton collisions at 7 TeV, comparing results with theoretical models and previous data, and analyzing the production ratios and scaling behaviors.

Contribution

First measurement of omega meson production cross section at 7 TeV in pp collisions, with detailed comparison to models and previous experiments.

Findings

PYTHIA 8.2 Monash 2013 describes data well

PYTHIA 8.2 Tune 4C overestimates data by ~50%

The omega/pi0 ratio is constant at 0.67 above 2.5 GeV/c

Abstract

The invariant differential cross section of inclusive $\omega(782)$ meson production at midrapidity ($|y|<0.5$) in pp collisions at $\sqrt{s}$ = 7 TeV was measured with the ALICE detector at the LHC over a transverse momentum range of 2 < $p_{\rm{T}}$ < 17 GeV/$c$. The $\omega$ meson was reconstructed via its $\omega\rightarrow\pi^+\pi^-\pi^0$ decay channel. The measured $\omega$ production cross section is compared to various calculations: PYTHIA 8.2 Monash 2013 describes the data, while PYTHIA 8.2 Tune 4C overestimates the data by about 50%. A recent NLO calculation, which includes a model describing the fragmentation of the whole vector-meson nonet, describes the data within uncertainties below 6 GeV/$c$, while it overestimates the data by up to 50% for higher $p_{\rm{T}}$. The $\omega/\pi^0$ ratio is in agreement with previous measurements at lower collision energies and the PYTHIA calculations. In addition, the measurement is compatible with transverse mass scaling within the measured $p_{\rm{T}}$ range and the ratio is constant with $C^{\omega/\pi^{0}}$ = 0.67 $\pm$ 0.03 (stat) $\pm$ 0.04 (sys) above a transverse momentum of 2.5 GeV/$c$.