Intersecting-Storage-Rings Inclusive Data and the Charge Ratio of Cosmic-Ray Muons

The ($\frac{{\mu }^{+}}{{\mu }^{-}}$) ratio at sea level has been calculated by Frazer et al., using the hypothesis of limiting fragmentation together with the inclusive data below 30 GeV/c. They obtained a value of $\frac{{\mu }^{+}}{{\mu }^{-}}\simeq 1.56$, to be compared with experimental value of 1.2 to 1.4. We have calculated the ratio using the recent ISR (CERN Intersecting Storage Rings) data, and obtained a value of $\frac{{\mu }^{+}}{{\mu }^{-}}\sim 1.40$ in good agreement with the experimental result.