Search for Cosmic-ray Antiproton Origins and for Cosmological Antimatter with BESS
Abstract
The BESS Collaboration performs elementary particle measurements in cosmic rays to study the early Universe and provides fundamental data on the spectra of light cosmic-ray elements and isotopes. BESS has advanced measurement of the cosmic-ray antiproton spectra to inves-tigate signatures of possible exotic sources, such as evaporation of primordial black holes and dark-matter candidates, and searches for heavier antinuclei that might reach Earth from anti-matter domains formed during symmetry breaking processes in the early Universe. Since1993, BESS has carried out eleven high-latitude balloon flights, two of long duration, that together have defined the study of antiprotons below about 4 GeV, provided standard references for light element and isotope spectra, and set the most sensitive limits on the existence of antideuterons and antihelium. The apex of the Balloon-borne Experiment with a Superconducting Spectrom-eter (BESS) program was reached with the Antarctic balloon flight of BESS-Polar II, during the 2007-2008 Austral Summer, that obtained 24.5 days of data on over 4.7 billion cosmic-ray events. The BESS-Polar II flight took place at the expected `solar minimum', when the sensitivity of the low-energy antiproton measurements to a primary source is greatest. The BESS-Polar II dataset more than doubles the combined data from all earlier BESS flights, and has 10-20 times the statistics of BESS data from the previous Solar minimum in 1995-1997. Here, we summarize the scientific results of BESS program, focusing on the results obtained from the long-duration flights of BESS.
- Publication:
-
38th COSPAR Scientific Assembly
- Pub Date:
- 2010
- Bibcode:
- 2010cosp...38.2649Y