Measurement of $J/\psi$ production in $pp$ collisions at $\sqrt{s}=7~\rm{TeV}$
Eur.Phys.J.C 71 (2011) 1645 , 2011.
The collaboration

Abstract (data abstract)
CERN-LHC. Measurement of the production of J/PSI mesons in proton-proton collisions at a centre-of-mass energy of 7 TeV. The data were collected during September 2010 with a total integrated luminosity of 5.2 pb$^{-1}$ and cover the fiducial range in transverse momentum ($p_T$) from 0 to 14 GeV/c and in rapidity ($y$) from 2.0 to 4.5. The data are separated into prompt $J/\psi$ production and $J/\psi$ from $b$-hadron decay, with three assumptions of the polarisation of the $J/\psi$ (none, fully transverse and fully longitudinal).