Measurement of the production cross-section of ψ(2S) →J/ψ (→ μ⁺μ⁻)π⁺ π⁻ in pp collisions at √s = 7 TeV at ATLAS

The prompt and non-prompt production cross-sections for ψ (2S) mesons are measured using 2.1 fb⁻¹ of pp collision data at a centre-of-mass energy of 7TeV recorded by the ATLAS experiment at the LHC. The measurement exploits the ψ (2S) → J/ψ (→ μ⁺μ⁻)π⁺π⁻ decay mode, and probes ψ (2S) mesons with transverse momenta in the range 10 ≤ pT < 100 GeV and rapidity |y| < 2.0. The results are compared to other measurements of ψ (2S) production at the LHC and to various theoretical models for prompt and non-prompt quarkonium production.