2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/48452I review the status of the extraction of NRQCD color-octet $J/ψ$ production matrix elements. Large theoretical uncertainties in current extractions from hadroproduction and photoproduction are emphasized. Leptoproduction of $J/ψ$ is calculated within the NRQCD factorization formalism. Color-octet contributions dominate the cross section, allowing for a reliable extraction of $<{\cal O}_8^{J/ψ}(^1S_0)>$ and $<{\cal O}_8^{J/ψ}(^3P_0)>$. A comparison with preliminary data from the H1 collaboration shows that leading order color-octet mechanisms agree with the measured total cross section for $Q^2 > 4m_c^2$, while the color-singlet model underpredicts the cross section by a factor of 5.5 pages, 2 figures, Talk given at XXIX International Conference on High Energy Physics, VancouverHigh Energy Physics - Phenomenologytext