Measurement of Cosmic Ray Antiprotons from 3.7 to 19 GeV

The antiproton to proton ratio, `p/p, in the cosmic rays has been measured in the energy range from 3.7 to 19 GeV. This measurement was carried out using a baloon-borne superconducting magnetic spectrometer along with a gas Cherenkov counter, an imaging calorimeter and a time of flight scintillator system. The measured `p/p ratio was determined to be 1.24 (+0.68, -0.51) x 10-4. The present result along with other recent observations show that the observed abundances of antiprotons are consistent with models, in which antiprotons are produced as secondaries during the propagation of cosmic rays in the Galaxy.