Initial momentum distribution of decaying muons

The initial momentum distribution for muons that then decay between two counters. The muons are degraded with a variety of thickness aluminium plates (indicated by colour) then passed through two counters that sandwich a 0.5mm copper stopping target. Muons are selected in the upstream counter and their decay daughter electrons in the downstream counter.

Simulation done using Geant4 with geometry based on the set up of the 5th MuSIC beam time.