Measurement of the cosmic-ray antiproton-to-proton abundance ratio between 4 and 50 GeV.

@article{Beach2001MeasurementOT,
  title={Measurement of the cosmic-ray antiproton-to-proton abundance ratio between 4 and 50 GeV.},
  author={A S Beach and James J. Beatty and Amit Bhattacharyya and Charles Bower and St{\'e}phane Coutu and M. A. Duvernois and A. W. Labrador and Sean McKee and Sharon Minnick and Dietrich M{\"u}ller and Jordan Musser and Sharon Nutter and Michael Schubnell and Simon P. Swordy and Gregory Tarl{\'e} and Andrew D. Tomasch},
  journal={Physical review letters},
  year={2001},
  volume={87 27 Pt 1},
  pages={271101}
}
We present a new measurement of the antiproton-to-proton abundance ratio, pbar/p, in the cosmic radiation. The HEAT-pbar instrument, a balloon borne magnet spectrometer with precise rigidity and multiple energy loss measurement capability, was flown successfully in Spring 2000, at an average atmospheric depth of 7.2 g/cm(2). A total of 71 antiprotons were identified above the vertical geomagnetic cutoff rigidity of 4.2 GV. The highest measured proton energy was 81 GeV. We find that the pbar/p… CONTINUE READING