[en] We present a new measurement of the cosmic-ray positron fraction at energies between 5 and 15 GeV with the balloon-borne HEAT-p-bar instrument in the spring of 2000. The data presented here are compatible with our previous measurements, obtained with a different instrument. The combined data from the three HEAT flights indicate a small positron flux of nonstandard origin above 5 GeV. We compare the new measurement with earlier data obtained with the HEAT-e^± instrument, during the opposite epoch of the solar cycle, and conclude that our measurements do not support predictions of charge sign dependent solar modulation of the positron abundance at 5 GeV

[en] We present a new measurement of atmospheric muons made during an ascent of the High Energy Antimatter Telescope balloon experiment. The muon charge ratio μ⁺/μ^- as a function of atmospheric depth in the momentum interval 0.3-0.9 GeV/c is presented. The differential μ^- intensities in the 0.3-50 GeV/c range and for atmospheric depths between 4-960 g/cm² are also presented. We compare these results with other measurements and model predictions. We find that our charge ratio is ∼1.1 for all atmospheric depths and is consistent, within errors, with other measurements and the model predictions. We find that our measured μ^- intensities are also consistent with other measurements, and with the model predictions, except at shallow atmospheric depths