More than a decade ago it was noticed that an unexpectedly large value of the measured cosmic antiproton flux at low kinetic energies could be interpreted in terms of a neutralino-induced component. An overproduction of low energy antiprotons seems however to be disfavoured by recent data from the Bess experiment. The strategy we propose here is to focus instead on the high energy antiproton sp...

High energy collisions of cosmic ray (CR) nuclei with interstellar gas are believed to be the mechanism producing the majority of CR antiprotons. The distinguishing spectral shape with a maximum at 2 GeV and a sharp decrease towards lower energies makes antiprotons a unique probe of the models of particle propagation in the Galaxy and modulation in the heliosphere. Besides, accurate calculation...

The BESS-Polar spectrometer had its first successful balloon flight over Antarctica in December 2004. During the 8.5-day long-duration flight, almost 0.9 billion events were recorded and 1,520 antiprotons were detected in the energy range 0.1–4.2 GeV. In this paper, we report the antiproton spectrum obtained, discuss the origin of cosmic-ray antiprotons, and use antiproton data to probe the eff...

Antiproton production from the secondary process pp~ pp is studied for nucleus-nucleus collisions at energies which are below the threshold for its production from the nucleon-nucleon reaction in the free space. In an expanding fireball model, we determine the p abundance from the fusion of pions and find that for collisions at 2. 1 GeV/nucleon the antiproton to negative pion ratio is = 5.5&10 ...

A major ingredient of the planned new accelerator complex FAIR, to be constructed at the GSI, Darmstadt, Germany, is the availability of antiproton beams with high quality and intensity. Among the experiments which will make use of this opportunity is PANDA, a dedicated experiment to study antiproton annihilations on nucleons and nuclei. This article gives an overview on the foreseen techniques...

We report on a new measurement of the cosmic ray antiproton spectrum. The data were collected by the balloon-borne experiment CAPRICE98, which was flown on 28-29 May 1998 from Fort Sumner, New Mexico, USA. The experiment used the NMSU-WIZARD/CAPRICE98 balloon-borne magnet spectrometer equipped with a gas Ring Imaging Cherenkov (RICH) detector, a time-of-flight system, a tracking device consisti...