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arXiv · 1111.1630

J/$ψ$ polarization in pp collisions at $\sqrt{s}=7$ TeV

ALICE Collaboration
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Abstract

We have studied J/psi production in pp collisions at $\sqrt{s}=7$ TeV at the LHC through its muon pair decay. The polar and azimuthal angle distributions of the decay muons were measured, and results on the J/$ψ$ polarization parameters $λ_θ$ and $λ_ϕ$ were obtained. The study was performed in the kinematic region 2.5<y<4, 2<$p_{\rm T}$<8 GeV/$c$, in the helicity and Collins-Soper reference frames. In both frames, the polarization parameters are compatible with zero, within uncertainties.

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ALICE Collaboration. 2017-09-27. J/$ψ$ polarization in pp collisions at $\sqrt{s}=7$ TeV. https://doi.org/10.1103/physrevlett.108.082001

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