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arXiv · 1712.08298

Nucleon shadowing effects in $Cu+Cu$ and $Au+Au$ collisions at RHIC within the HIJING code

Khaled Abdel-Waged·Nuha Felemban
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Abstract

The centrality dependence of pseudorapidity density of charged particles ($ dN_{ch}/dη$) in $Cu+Cu$ ($Au+Au$) collisions at RHIC energy of $ \sqrt{s_{_{\rm NN}}}=22.4$ , $62.4 $ and $200$ ($19.6$, $62.4$ and $200$) GeV, is investigated within an improved HIJING code. The standard HIJING model is enhanced by a prescription for collective nucleon-nucleon ($NN$) interactions and more modern parton distribution functions. The collective $NN$-interactions are used to induce both cascade and nucleon shadowing effects. We find collective cascade broadens the pseudorapidity distributions in the tails (at $ |η|> y_{\rm beam} $) above $25-30\%$ collision centrality to be consistent with the $ dN_{ch}/dη$ data at $ \sqrt{s_{_{\rm NN}}}=19.6$, $22.4$, $62.4 $ GeV. The overall contribution of nucleon shadowing is shown to depress the whole shape of $ dN_{ch}/dη$ in the primary interaction region (at $ |η|< y_{\rm beam} $) for semiperipheral ($ 20-25 $ \%) and peripheral ($\ge 35-40$\%) $Cu+Cu$ ($Au+Au$) interactions at $ \sqrt{s_{_{\rm NN}}}=200$ GeV, in accordance with the PHOBOS data.

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Khaled Abdel-Waged, Nuha Felemban. 2017-12-22. Nucleon shadowing effects in $Cu+Cu$ and $Au+Au$ collisions at RHIC within the HIJING code. https://doi.org/10.1088/1361-6471%2Faaa101

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