Study of the strong coupling constants, α<sub>s</sub> (q<sup>2</sup> ) of π- and K<sup>0</sup> mesons from π<sup>-</sup>+p and π<sup>-</sup>+C interactions at 40 GeV/c

This paper is devoted to the production of π-and K0 mesons from π-+p→π-+X and π-+C→π-,K0+X interactions at 40 GeV/c as a function of the square of four momentum transfer. The cut parameter of the strong coupling constant is taken as Λac2=ma2+mc2. Values of the strong coupling constant are then compared to leading-order and next-to-leading-order perturbative QCD calculations for the first time. Agreement between the experimental data and theory is good, thus providing a precision test of QCD at large momentum transfers (q). The strong coupling constant αs is extracted as a function of q, showing a good agreement with the renormalisation group equation and with previous analyses. As the momentum transfers increases, the running coupling constant decreases. For each high-energy interaction, a quantity called the cut parameter is chosen differently depending on the secondary particles produced by the reaction. For each high-energy interaction, a quantity called the cut parameter is chosen differently depending on the secondary particles produced by the reaction.