Novel and self-consistency analysis of the QCD running coupling $\hat{I}{\pm }_s(Q)$ in both the perturbative and nonperturbative domains

Abstract

The QCD coupling $\hat{I}{\pm }_s$ is the most important parameter for achieving precise QCD predictions. By using the well measured effective coupling $\hat{I}{\pm }_s^{g_1}(Q)$ defined from the Bjorken sum rules as a basis, we suggest a novel and self-consistency way to fix the $\hat{I}{\pm }_s$ at all scales: The QCD light-front holographic model is adopted for its infrared behavior, and the fixed-order pQCD prediction under the principle of maximum conformality (PMC) is used for its high-energy behavior. Using the PMC scheme-and-scale independent perturbative series, and by transforming it into the one under the physical $V$-scheme, we observe that a precise $\hat{I}{\pm }_s$ running behavior in both the perturbative and nonperturbative domains with a smooth transition from small to large scales can be achieved.

6 pages,3 figures