Precision measurement of cosmic-Ray antiproton spectrum
The energy spectrum of cosmic-ray antiprotons ( &pmacr;'s) has been measured in the range 0.18-3.56 GeV, based on 458 &pmacr;'s collected by BESS in a recent solar-minimum period. We have detected for the first time a characteristic peak at 2 GeV of &pmacr;'s originating from cosmic-ray interactions with the interstellar gas. The peak spectrum is reproduced by theoretical calculations, implying that the propagation models are basically correct and that different cosmic-ray species undergo a universal propagation. Future BESS data with still higher statistics will allow us to study the solar modulation and the propagation in detail and to search for primary &pmacr; components.
Orito
S
University of Tokyo, Tokyo 113-0033, Japan.
Maeno
T
Matsunaga
H
Abe
K
Anraku
K
Asaoka
Y
Fujikawa
M
Imori
M
Ishino
M
Makida
Y
Matsui
N
Matsumoto
H
Mitchell
J
Mitsui
T
Moiseev
A
Motoki
M
Nishimura
J
Nozaki
M
Ormes
J
Saeki
T
Sanuki
T
Sasaki
M
Seo
ES
Shikaze
Y
Sonoda
T
Streitmatter
R