@article{10902/25582, year = {2013}, month = {12}, url = {http://hdl.handle.net/10902/25582}, abstract = {The polarizations of prompt J/ψ and ψ(2S) mesons are measured in proton-proton collisions at √s = 7 TeV, using a dimuon data sample collected by the CMS experiment at the LHC, corresponding to an integrated luminosity of 4.9 fb-1. The prompt J/ψ and ψ(2S) polarization parameters λθ, λφ, and λθφ, as well as the frame-invariant quantity λ~, are measured from the dimuon decay angular distributions in three different polarization frames. The J/ψ results are obtained in the transverse momentum range 14