Production and polarization of $S$-wave quarkonia in potential nonrelativistic QCD

Understand

Based on the potential nonrelativistic QCD formalism, we compute the nonrelativistic QCD long-distance matrix elements (LDMEs) for inclusive production of $S$-wave heavy quarkonia.

• This greatly reduces the number of nonperturbative unknowns and brings in a substantial enhancement in the predictive power of the nonrelativistic QCD factorization formalism.
• We obtain improved determinations of the LDMEs and find cross sections and polarizations of $J/\psi$, $\psi(2S)$, and excited $\Upsilon$ states that agree well with LHC data.
• Our results may have important implications in pinning down the heavy quarkonium production mechanism.