2022/03/10 by Jorge Portoles, Portoles, Jorge
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Experiment (hep-ex) #High Energy Physics - Phenomenology (hep-ph) #hep-ex #hep-ph
paper · pdf · doi:10.48550/arxiv.2203.05310
10 pp, 4 Fig. Lecture given at the XIX Mexican School of Particles and Fields (online; 9-13 August 2021)
arxiv created 2022/03/10 · arxiv updated 2022/03/11
Within our present knowledge, the tau is the heaviest lepton and the only one decaying into hadrons, a fact that makes it the source of a very rich phenomenology. It represents the third family of leptons in the Standard Model, a feature that helps its classification but whose real meaning is not asserted yet. The tau lepton provides: i) a clean and unique environment to study both the hadronization of QCD currents, in an energy region populated by resonances, and the phenomenological determination of relevant parameters of the Model; ii) together with the muon, they have a very constrained flavour dynamics (in the absence of neutrino masses) due to an accidental global symmetry of the Standard Model. In consequence, the tau lepton brings an excellent benchmark for the study of QCD at low energies and, at the same time, for the search of new physics.