Determination of the strong coupling $\alpha_{\mathrm{s}}$ from transverse energy-energy correlations in multi-jet events at $\sqrt{s} = 13\;\mbox{TeV}$ with the ATLAS detector

Multi-jet events registered with the ATLAS detector during the proton-proton LHC Run 2 are used to determine the strong coupling constant $\alpha_{\mathrm{s}}$ from transverse energy-energy correlations and their associated asymmetries. The measurements are presented in bins of the scalar sum of the transverse momenta of the two leading jets, $H_{\mathrm{T}2}$. This thesis contains the first comparison of experimental data with perturbative QCD calculations at next-to-next-to-leading order for three-jet production. The agreement between data and theory is excellent, thus providing a precision test of QCD at large momentum transfers. A simultaneous fit to all $H_{\mathrm{T}2}$ bins yields a value of $\alpha_{\mathrm{s}}(m_Z) = 0.1175 \pm 0.0006 \ (\mathrm{fit}) \ ^{+0.0034}_{-0.0017} \ (\mathrm{theo.})$ for the transverse energy-energy correlations and $\alpha_{\mathrm{s}}(m_Z) = 0.1185 \pm 0.0009 \ (\mathrm{fit}) \ ^{+0.0025}_{-0.0012} \ (\mathrm{theo.})$ for their asymmetries.