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arXiv · 1012.1954

Polarization of prompt J/psi in pp -> J/psi+X at sqrt{s}=200 GeV

Hee Sok Chung·Seyong Kim·Jungil Lee·Chaehyun Yu
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Abstract

Within the framework of the nonrelativistic QCD factorization approach, we compute the cross section and polarization of prompt J/psi produced from proton-proton collisions at the center-of-momentum energy sqrt{s}=200 GeV. We present the transverse-momentum distribution in the forward-rapidity region 1.2 < |y| < 2.2 and the rapidity distribution over the transverse-momentum range 2 GeV < p_T < 20 GeV. The perturbative contributions are computed at leading order in the strong coupling constant. We predict slight transverse polarization of J/psi in the forward-rapidity region, while that for the mid-rapidity region is slightly longitudinal. The transverse-momentum distribution agrees well with the PHENIX preliminary data and the color-singlet-model prediction at next-to-leading order in alpha_s, but disagrees with the result from the leading-order color-singlet model or the s-channel-cut method.

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Hee Sok Chung, Seyong Kim, Jungil Lee, Chaehyun Yu. 2010-12-09. Polarization of prompt J/psi in pp -> J/psi+X at sqrt{s}=200 GeV. https://doi.org/10.1103/physrevd.83.037501

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