The energy spectrum of cosmic-ray antiprotons (p̄'s) from 0.17 to 3.5GeV has been measured using 7886 p̄'s detected by BESS-PolarII during a long-duration flight over Antarctica near solar minimum in December 2007 and January 2008. This shows good consistency with secondary p̄ calculations. Cosmologically primary p̄'s have been investigated by comparing measured and calculated p̄ spectra. BESS-PolarII data show no evidence of primary p̄'s from the evaporation of primordial black holes.
ASJC Scopus subject areas
- Physics and Astronomy(all)