Measurement of $\psi (2S)$ nuclear modification at backward and forward rapidity in $p$$+$$p$, $p$$+$Al, and $p$$+$Au collisions at $\sqrt{s_{{}_{NN}}}=200$ GeV

U. A. Acharya, C. Aidala, Y. Akiba +313

Suppression of the $J/\psi$ nuclear-modification factor has been seen as a trademark signature of final-state effects in large collision systems for decades. In small systems, the nuc…