2013/11/29 by Linlin Zhang, Zhang, Linlin
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Experiment (hep-ex) #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-ex
paper · pdf · doi:10.48550/arxiv.1311.7490
to appear in the proceedings of The 6th International Workshop on Charm Physics (CHARM 2013)
arxiv created 2013/11/29 · openalex publication_date 2013/11/29 · arxiv updated 2013/12/02 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The polarizations of Y(nS) (n=1,2,3) and prompt J/ψand ψ(2S), as well as the differential cross section of the Y(nS), are measured in proton-proton collisions at sqrt(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 differential cross section is measured as a function of transverse momentum of Y(nS). The data show a transition from exponential to power-law behavior in the neighborhood of 20 GeV, and the power-law exponents for all three states are consistent. The 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. No evidence of large polarizations is seen in these kinematic regions, which extend much beyond those previously explored.