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

Abstract

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.