The muonic longitudinal shower profiles at production
  In this paper the longitudinal profile of muon production along the shower axis is studied. The characteristics of this distribution is investigated for different primary masses, zenith angles, primary energies, and different high energy hadronic models. It is found that the shape of this distribution displays universal features similarly to what is known for the electromagnetic profile. The relation between the muon production distribution and the longitudinal electromagnetic evolution is also discussed. 
S. Andringa, L. Cazon, R. Concei\c{c}\~ao, M. Pimenta
hep-ph hep-ex