Measurement of an Excited Charmonium State and the Study of image Polarization in image Collisions at image in PHENIX Experiment at RHIC Original Research Article

We report the J/ψ→e+e− and the ψ′→e+e− production cross sections in the PHENIX experiment at RHIC. The first measurements of the production cross sections of the ψ′ and the ψ′ over the J/ψ, will contribute to the clarification of the theoretical understanding of the J/ψ meson production. The inclusive J/ψ polarization through the same decay channel is also presented, showing a trend of slightly longitudinal polarization for pT<5 GeV/c.