Elliptic flow as a probe for $ψ(2S)$ production mechanism in relativistic heavy ion collisions

Abstract

I discuss the elliptic flows of $ψ(2S)$ with different production mechanisms in $\sqrt{s_{NN}}=2.76$ TeV Pb-Pb collisions. If the final $ψ(2S)$s are mainly from the recombination of uncorrelated charm and anticharm quarks at $T\approx T_c$, charm and anticharm quarks will carry large collective flows of the bulk medium, which will be inherited by the regenerated $ψ(2S)$s. This indicates a larger elliptic flow of $ψ(2S)$ than that of $J/ψ$ which can be regenerated at $T\ge T_c$, $v_2^{ψ(2S)}>v_2^{J/ψ}$. However, if the final $ψ(2S)$s are mainly from the transitions of $J/ψ\rightarrow ψ(2S)$ caused by the color screening of QGP, its elliptic flow should be close to the elliptic flow of $J/ψ$, $v_2^{ψ(2S)}\sim v_2^{J/ψ}$. Therefore, $ψ(2S)$ elliptic flow is a sensitive probe for its production mechanisms in relativistic heavy ion collisions.