Cosmic-Ray Antiproton Flux in the Energy Range from 200 to 600 MeV

Authors :: Moiseev, A.
Yoshimura, K.
Ueda, I.
Anraku, K.
Golden, R.
Imori, M.
Inaba, S.
Kimbell, B.
Kimura, N.
Makida, Y.
Matsumoto, H.
Matsunaga, H.
Mitchell, J.
Motoki, M.
Nishimura, J.
Nozaki, M.
Orito, S.
Ormes, J.
Saeki, T.
Seo, E. S.
Stochaj, S.
Streitmatter, R.
Suzuki, J.
Tanaka, K.
Yajima, N.
Yamagami, T.
Yamamoto, A.
Yoshida, T.
Source :: The Astrophysical Journal; January 1997, Vol. 474 Issue: 1 p479-489, 11p
Publication Year :: 1997
Abstract: We have studied the low-energy antiprotons in the cosmic rays by utilizing data obtained by the Balloon-borne Experiment with a Superconducting magnetic rigidity Spectrometer (BESS) flown in 1993 July from Lynn Lake, Manitoba, Canada. A detailed description of the event selection criteria and background corrections is given. Seven antiprotons are found that give an antiproton flux of 6.4+ 5.5?3.5× 10-3(m2sr s GeV)-1and an antiproton/proton ratio of 5.2+ 4.4?2.8× 10-6in the 200-600 MeV energy range. These results are consistent with a secondary origin of low-energy cosmic-ray antiprotons within our uncertainties, but they still require the precise measurement of the spectrum shape below 500 MeV to clarify exactly the model of particle propagation and possible contributions from exotic sources.