Abstract : The first LHCb measurement of the J/ψ production cross-section is presented. The differential production cross-section is measured as a function of the J/ψ transverse momentum p_T in the range _pT ∈ [0; 10] GeV/c and rapidity y in the range y ∈[2.5;4]. The analysis is based on a sample of 14.2 nb^−1 collected between April and June 2010 at the pp Large Hadron Collider at CERN, at a center-of-mass energy √s = 7 TeV. The fraction of J/ψ coming from b-hadron decays is estimated using the J/ψ pseudo-propertime.
P. Robbe. LHCb first J/ψ cross-section measurement. Quarkonium 2010. "Three Days of Quarkonium Production in Proton-Proton and Proton-Nucleus Collisions", Jul 2010, Palaiseau, France. pp.52-55, ⟨10.1016/j.nuclphysbps.2011.03.057⟩. ⟨in2p3-00579413⟩