An analytic Pade-motivated QCD coupling

Understand

We consider a modification of the Minimal Analytic (MA) coupling of Shirkov and Solovtsov.

• This modified MA (mMA) coupling reflects the desired analytic properties of the space-like observables.
• We show that an approximation by Dirac deltas of its discontinuity function $\rho$ is equivalent to a Pad\'e (rational) approximation of the mMA coupling that keeps its analytic structure.
• We propose a modification to mMA that, as preliminary results indicate, could be an improvement in the evaluation of low-energy observables compared with other analytic couplings.