Measurement of the cross-section ratio σ(χ c2)/σ(χ c1) for prompt χ c production at s=7 TeV

Journal article

The prompt production of the charmonium χ c1 and χ c2 mesons has been studied in proton-proton collisions at the Large Hadron Collider at a centre-of-mass energy of s=7 TeV. The χ c mesons are identified through their decays χ c→J/ψγ with J/ψ→μ +μ - using 36 pb -1 of data collected by the LHCb detector in 2010. The ratio of the prompt production cross-sections for the two χ c spin states, σ(χ c2)/σ(χ c1), has been determined as a function of the J/ψ transverse momentum, pTJ/ψ, in the range from 2 to 15 GeV/c. The results are in agreement with the next-to-leading order non-relativistic QCD model at high pTJ/ψ and lie consistently above the pure leading-order colour-singlet prediction. © 2012 CERN.

Authors: Aaij, R; Abellan Beteta, C; Abellan Beteta, C; Adeva, B; Adinolfi, M

• Journal: Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
• Volume: 714
• Issue: 2-5
• Pages: 215-223
• Publication date: 2012-08-14
• DOI: 10.1016/j.physletb.2012.06.077
• ISSN: 0370-2693