J/$ψ$ suppression at $\sqrt{\bf s} =$ 200 GeV in the comovers interaction model

Abstract

The yield of $J/ψ$ per binary nucleon-nucleon collision in $AuAu$ and $CuCu$ collisions at $\sqrt{s} = 200$ GeV is computed in the framework of the dual parton model, supplemented with final state interaction (comovers interaction). For the latter we use the same value of the cross-section, $σ_{co} = 0.65$ mb, which describes the anomalous $J/ψ$ suppression observed at CERN-SPS energies. Several possibilities for the value of the absorptive cross-section are considered. Shadowing is introduced in both the comovers and the $J/ψ$ yields. A comparison with the results at CERN-SPS, including a prediction for $InIn$ collisions, is also presented.