A precision measurement by AMS of the antiproton-to-proton flux ratio in primary cosmic rays in the absolute rigidity range from 1 to 450 GV is presented based on $3.49\times10^5$ antiproton events and $2.42\times10^9$ proton events. Above $\sim60$ GV the antiproton to proton flux ratio is consistent with being rigidity independent. A decreasing behaviour is expected for this ratio considering the traditional models for the secondary antiproton flux.
Precision Measurement of Boron-to-Carbon ratio in Cosmic Rays from 2 GV to 2 TV with the Alpha Magnetic Spectrometer on the International Space Station
Precision measurement of the (e$^+$ + e$^-$) flux in primary cosmic rays from 0.5 GeV to 1 TeV with the Alpha Magnetic Spectrometer on the International Space Station
Precision measurement of the cosmic-ray electron and positron fluxes as a function of time and energy with the Alpha Magnetic Spectrometer on the International Space Station
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