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arXiv · 0806.0736

Negative Elliptic Flow of $J/ψ$'s: A Qualitative Signature for Charm Collectivity at RHIC

Daniel Krieg·Marcus Bleicher
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Abstract

We discuss one of the most prominent features of the very recent preliminary elliptic flow data of $J/Ψ$ meson from the PHENIX collaboration \cite{Silvestre:2008tw}. Even within the the rather large error bars of the measured data a negative elliptic flow parameter ($v_2$) for $J/Ψ$ in the range of $p_T=0.5-2.5 \GeV/c$ is visible. We argue that this negative elliptic flow at intermediate $p_T$ is a clear and qualitative signature for the collectivity of charm quarks produced in nucleus-nucleus reactions at RHIC. Within a parton recombination approach we show that a negative elliptic flow puts a lower limit on the collective transverse velocity of heavy quarks. The numerical value of the transverse flow velocity $β_T$ for charm quarks that is necessary to reproduce the data is $β_T(charm)\sim 0.55-0.6c$ and therefore compatible with the flow of light quarks.

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Daniel Krieg, Marcus Bleicher. 2008-12-10. Negative Elliptic Flow of $J/ψ$'s: A Qualitative Signature for Charm Collectivity at RHIC. https://doi.org/10.1140/epja/i2008-10700-9

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