Muon pair production in 16 and 22 GeV πCu collisions

We have measured inclusive muon pair production by 16 and 22 GeV π- on a copper target in a wide aperture magnetic spectrometer. We interpret the data in terms of quark annihilation models and find approximate scaling in the variable τ = M2/s over a wide energy range. At large values of τ the yield of μ-pairs produced by π- is ∼ 100 times that produced by protons. This effect can be understood by assuming appropriate quark distributions for π- and p and thus provides experimental insight into the inner structure of these particles. © 1979