Muon lifetime and muon capture
  We present an introduction to the MuLAN and MuCAP experiments at PSI, which aim at high precision determinations of two fundamental Weak Interactions parameters: the Fermi constant $G_{F}$ and the induced pseudoscalar form factor $g_{p}$, respectively. 
MuCAP Collaboration and MuLAN Collaboration (Bernhard Lauss for the   Collaboration)