Muon emittance and pion decay

An efficient collection of muons is a crucial task for machines such as neutrino factories or muon colliders. The definition of the beam emittance and the determination of the capture efficiencies both in transverse and longitudinal spaces is made difficult by the transition from the pion to the muon beam through the decay process. An analytical approach to the problem is derived for a transport line where path length variations can be neglected.