Light vector meson production in pp collisions at $\sqrt{s}$ = 7 TeV

Abstract

The ALICE experiment has measured low-mass dimuon production in pp collisions at $\sqrt{s} = 7$ TeV in the dimuon rapidity region 2.5<y<4. The observed dimuon mass spectrum is described as a superposition of resonance decays ($η$, $ρ$, $ω$, $η^{'}$, $ϕ$) into muons and semi-leptonic decays of charmed mesons. The measured production cross sections for $ω$ and $ϕ$ are $σ_ω$ (1<$p_{\rm T}$<5 GeV/$c$,2.5<y<4) = 5.28 $\pm$ 0.54 (stat) $\pm$ 0.50 (syst) mb and $σ_ϕ$(1<$p_{\rm T}$<5 GeV/$c$,2.5<y<4)=0.940 $\pm$ 0.084 (stat) $\pm$ 0.078 (syst) mb. The differential cross sections $d^2σ/dy dp_{\rm T}$ are extracted as a function of $p_{\rm T}$ for $ω$ and $ϕ$. The ratio between the $ρ$ and $ω$ cross section is obtained. Results for the $ϕ$ are compared with other measurements at the same energy and with predictions by models.