The top quark is the heaviest known particle, and the only colored one that decays before hadronization. Its mass is a fundamental parameter of the standard model. Precision measurements of the top-quark mass can be used to test the self-consistency of the standard model and, at the same time, to study effects of non-perturbative QCD. CMS recently completed the set of standard top quark mass measurements at 8 TeV in all three decay channels, reaching sub-GeV uncertainty for the first time in a single analysis and combining to the most precise single-experiment measurement. With the steady increase in experimental precision comes a theoretical challenge of interpreting the results and the motivation of using alternative methods. In this talk we present the CMS set of analyses using the 8 TeV dataset, both with conventional methods and non-standard techniques targeting different definitions of the top quark mass. Furthermore we give an outlook at expected future improvements in both standard and alternative approaches, the outcome of which might just determine the fate of our universe.
M. Mangano, C. Lourenco, G. Unal