QCD since the CSR are a central pQCD prediction independent of theoretical conventions. The normalization of the QCD coupling α AdS s at Q 2 = 0 appears to be considerably higher than that suggested in Ref. [1], a difference probably stemming from the different scheme choices. However, α$_{g}$$_{1}$ ( Q $^{2}$) has the advantage that it is the most precisely measured effective charge. As we have noted, there is a remarkable similarity of α$_{g}$$_{1}$ ( Q $^{2}$) to the nonperturbative strong coupling α AdS s ( Q $^{2}$) obtained here except at large Q 2 where the contribution from quantum loops is dominant. To extend its utility, we have provided an analytical expression encompassing the holographic result at low Q 2 and pQCD contributions from gluon exchange at large Q $^{2}$. The value of the confining scale of the model κ is determined from the vector meson Regge trajectory, so our small Q $^{2}$-dependence prediction is parameter free. There are many phenomenological applications where detailed knowledge of the QCD coupling and the renormalized gluon propagator at relatively soft momentum transfer are essential. This includes the rescattering (final-state and initial-state interactions), which create the leading-twist Sivers single-spin correlations in semi-inclusive deep inelastic scat- tering, [64, 65] the Boer-Mulders functions which lead to anomalous cos 2 φ contributions to the lepton pair angular distribution in the unpolarized Drell-Yan reaction, [66] and the Sommerfeld-Sakharov-Schwinger correction to heavy quark production at threshold. [67] The confining AdS/QCD coupling from light-front holography can lead to a quantitative understanding of this factorization-breaking physics. [68] We thank A. Radyushkin for helpful, critical remarks. We also thank V. Burkert, J. Cornwall, H.G. Dosch, J. Erlich, P. H¨ agler, W. Korsch, J. K¨ uhn, G. P. Lepage, T. Okui, and J. Papavassiliou for helpful comments. We thank S. Furui for sending us his recent lattice results. This research was supported by the Department of Energy under Contract No. DE–AC02–76SF00515. A.D.’s work is supported by the U.S. Department of Energy (DOE). The Jefferson Science Associates (JSA) operates the Thomas Jefferson National Accelerator Facility for the DOE under Contract No. DE–AC05–84ER40150. S.J.B. thanks the Hans Christian Andersen Academy and the CP $^{3}$-Origins Institute for their support at Southern Denmark University. ACKNOWLEDGMENTS 23