Antimatter search with AMS (Alpha Magnetic Spectrometer) during STS-91 precursor flight

The Alpha Magnetic Spectrometer (AMS) is designed to study the antimatter, matter and dark matter in space. AMS successfully flown on space shuttle Discovery during precursor flight STS-91 in a 51.7 degree sign orbit at altitudes between 320 and 390 km. No antimatter nuclei with Z ≥ 2 were detected. In this report we present the AMS performances during shuttle flight and we give new limits on antimatter/matter flux ratio