title: Precision measurement of cosmic-Ray antiproton spectrum
abstract: 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.
authors.affiliation: University of Tokyo, Tokyo 113-0033, Japan.
authors.initials: S
authors.lastname: Orito
authors.initials: T
authors.lastname: Maeno
authors.initials: H
authors.lastname: Matsunaga
authors.initials: K
authors.lastname: Abe
authors.initials: K
authors.lastname: Anraku
authors.initials: Y
authors.lastname: Asaoka
authors.initials: M
authors.lastname: Fujikawa
authors.initials: M
authors.lastname: Imori
authors.initials: M
authors.lastname: Ishino
authors.initials: Y
authors.lastname: Makida
authors.initials: N
authors.lastname: Matsui
authors.initials: H
authors.lastname: Matsumoto
authors.initials: J
authors.lastname: Mitchell
authors.initials: T
authors.lastname: Mitsui
authors.initials: A
authors.lastname: Moiseev
authors.initials: M
authors.lastname: Motoki
authors.initials: J
authors.lastname: Nishimura
authors.initials: M
authors.lastname: Nozaki
authors.initials: J
authors.lastname: Ormes
authors.initials: T
authors.lastname: Saeki
authors.initials: T
authors.lastname: Sanuki
authors.initials: M
authors.lastname: Sasaki
authors.initials: ES
authors.lastname: Seo
authors.initials: Y
authors.lastname: Shikaze
authors.initials: T
authors.lastname: Sonoda
authors.initials: R
authors.lastname: Streitmatter