$\alpha_S$ from soft QCD jet fragmentation functions

We present an extraction of the QCD coupling $\alpha_s$ from the energy evolution of the first two moments (multiplicity and peak position) of the parton-to-hadron fragmentation functions at low fractional hadron momentum $z$. A fit of the experimental jet data, from $e^+e^−$ and deep-inelastic $e^{\pm}, ν-p$ collisions, to NNLO$^∗$+NNLL predictions yields $\alpha_s(m_Z)= 0.1205 \pm 0.0010 \rm{(exp)}^{+0.0022}_{−0.0000}\rm{(th)}$, in good agreement with the current $\alpha_s$ world-average value.