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Search for antihelium in cosmic rays

AMS Collaboration
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Abstract

The Alpha Magnetic Spectrometer (AMS) was flown on the space shuttle Discovery during flight STS-91 in a 51.7 degree orbit at altitudes between 320 and 390 km. A total of 2.86 * 10^6 helium nuclei were observed in the rigidity range 1 to 140 GV. No antihelium nuclei were detected at any rigidity. An upper limit on the flux ratio of antihelium to helium of < 1.1 * 10^-6 is obtained.

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AMS Collaboration. 2000-02-17. Search for antihelium in cosmic rays. https://doi.org/10.1016/s0370-2693(99)00874-6

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