New measurement of the altitude dependence of the atmospheric muon intensity

We present a new measurement of atmospheric muons made during an ascent of the High Energy Antimatter Telescope balloon experiment. The muon charge ratio {mu}{sup +}/{mu}{sup -} as a function of atmospheric depth in the momentum interval 0.3-0.9 GeV/c is presented. The differential {mu}{sup -} intensities in the 0.3-50 GeV/c range and for atmospheric depths between 4-960 g/cm{sup 2} are also presented. We compare these results with other measurements and model predictions. We find that our charge ratio is {approx}1.1 for all atmospheric depths and is consistent, within errors, with other measurements and the model predictions. We find that our measured {mu}{sup -} intensities are also consistent with other measurements, and with the model predictions, except at shallow atmospheric depths.