Phenomenology of the Weak Interaction

Abstract

Quarks and leptons are equally affected by the weak interaction. At the beginning of this chapter we first present the properties of the three charged leptons and the associated neutrinos followed by a discussion of the various types of weak interactions: leptonic, semileptonic and non-leptonic processes. These are mediated by the exchange of the heavy W± and bosons. The coupling strength of the weak interaction is determined from muon decay. The CKM matrix is introduced, whose matrix elements quantify transitions from one quark flavour to another. The weak interaction violates parity conservation. Examples presented are the muon decay and the helicity suppressed pion decay. Finally, we present charged-current deep-inelastic scattering with beams of neutrinos and antineutrinos and of polarised electrons and positrons.