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$Ψ'/Ψ$ ratio in Nucleus-Nucleus Collisions : a Measure for the Chiral Symmetry Restoration Temperature ?

Heinz Sorge·Edward Shuryak·Ismail Zahed
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Abstract

We argue that a decrease of the chiral scalar meson mass is responsible for re-creation of $Ψ'$ from $J/Ψ$ in ultrarelativistic nucleus-nucleus collisions. This causes the charmonium yields to freeze out at temperatures close to the chiral symmetry restoration temperature $T_c$. As a result $Ψ'/Ψ$ may serve as a thermometer for $T_c$ itself. Results in a detailed reaction model support the conjecture. They show good agreement with recent data of NA38 and NA50 for $J/Ψ$ and $Ψ'$ production in S on U and Pb on Pb collisions.

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Heinz Sorge, Edward Shuryak, Ismail Zahed. 1997-05-15. $Ψ'/Ψ$ ratio in Nucleus-Nucleus Collisions : a Measure for the Chiral Symmetry Restoration Temperature ?. https://doi.org/10.1103/physrevlett.79.2775

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