Resolving the universality and polarization puzzles in $J/\psi$ hadroproduction

An-Ping Chen, Jun Guo, Yan-Qing Ma

Prompt $J/\psi$ hadroproduction poses two related puzzles: fixed-order hadronic and $e^{+}{e}^{-}$ analyses give incompatible constraints on the same color-octet (CO) long-distance matrix e…