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

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