Search for Antimatter with the AMS Cosmic Ray Detector
Antimatter search results of the Alpha Magnetic Spectrometer (AMS) detector are presented. About 10{sup 8} triggers were collected in the 1998 precursor flight onboard space shuttle Discovery. This ten day mission exposed the detector on a 51.7{sup o} orbit at an altitude around 350km. Identification of charged cosmic rays is achieved by multiple energy loss and time-of-flight measurements. Bending inside the 0.15T magnetic volume yields a measurement of the absolute value of the particle's rigidity. The supplemental knowledge of the sense of traversal identifies the sign of the charge. In the rigidity range 1 < R < 140 GV no antinucleus at any rigidity was detected, while 2.86 x 10{sup 6} helium and 1.65 x 10{sup 5} heavy nuclei were precisely measured. Hence, upper limits on the flux ratio {bar Z}/Z are given. Different prior assumptions on the antimatter spectrum are considered and corresponding limits are given.
- Research Organization:
- SLAC National Accelerator Lab., Menlo Park, CA (United States)
- Sponsoring Organization:
- USDOE Office of Science (US)
- DOE Contract Number:
- AC03-76SF00515
- OSTI ID:
- 812975
- Report Number(s):
- SLAC-PUB-9691; TRN: US0303543
- Resource Relation:
- Other Information: PBD: 24 Mar 2003
- Country of Publication:
- United States
- Language:
- English
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