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Nuclear Effects on Charmonium Production

Xiao-Fei Zhang·Cong-Feng Qiao·Xiao-Xia Yao·Wei-Qin Chao
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Abstract

$J/ψ$ and $ψ'$ production cross sections in fixed-target experiment is calculated, considering the contributions from both color-singlet and color-octet mechanisms.The results are applied to the investigations of the $J/ψ$ suppression and the $ψ'/ψ$ ratio problems in p-A collisions. The results agree with the experimental data as the $(c \bar c)-$nucleon absorption cross sections $σ_{abs}^8\simeq 10mb $ for $(c \bar c)_8$ and $σ_{abs}^1\simeq 0mb $ for $(c \bar c)_1$. The model is further used to investigate A-A collisions when comover absorption mechanism is also considered. It is found that the observed experiment data of $J/ψ$ and $ψ'/ψ$ ratio in S-U collisions and Pb-Pb collisions can not be explained consistently within this model. The possibility of QGP formation in S-U and Pb-Pb collisions is also discussed.

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Xiao-Fei Zhang, Cong-Feng Qiao, Xiao-Xia Yao, Wei-Qin Chao. 1997-11-05. Nuclear Effects on Charmonium Production. https://arxiv.org/abs/hep-ph/9711237

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