Limiting Fragmentation and the Charge Ratio of Cosmic-Ray Muons

Combining the steeply falling primary cosmic-ray spectrum with the scaling hypothesis for the spectrum of produced secondary particles, we illustrate how to correlate data at machine energies with cosmic-ray phenomena. We find that the $\frac{{\mu }^{+}}{{\mu }^{-}}$ ratio is expected to be energy-independent and greater than 1, regardless of the specific model chosen for multiparticle hadronic reactions. An analysis of accelerator data gives the value $\frac{{\mu }^{+}}{{\mu }^{-}}\approx 1.56$, to be compared with the experimental result ∼ 1.25. Possible causes of this discrepancy are discussed.