Speaker
Description
We present a new determination of the strong coupling constant $\alpha_s(M_Z)$ from a global QCD analysis CT25 of parton distribution functions (PDFs) that incorporates high-precision experimental measurements from the Run-2 of the Large Hadron Collider together with a large sample of other measurements over a wide interval of energies. In addition to providing an up-to-date determination of $\alpha_s(M_Z)$ using NNLO calculations and a sensitive nucleon data set within a self-consistent framework, we critically assess the estimation of the uncertainty on $\alpha_s(M_Z)$ using some commonly used criteria, including the dynamical tolerance and Bayesian hierarchical models. Based on this in-depth examination of the CT25 global hadronic data set using a combination of analysis methods, we find $\alpha_s(M_Z) = 0.1183^{+ 0.0023}_{-0.0020}$ at the 68% credibility level.