Search for Antihelium in the Cosmic Rays

, , , , , , , , and

© 1997. The American Astronomical Society. All rights reserved. Printed in U.S.A.
, , Citation R. L. Golden et al 1997 ApJ 479 992 DOI 10.1086/303886

0004-637X/479/2/992

Abstract

On 1987 August 22 a balloon flight was conducted using the Goddard Space Flight Center Low-Energy Antiproton configuration of the New Mexico State University balloon-borne magnet spectrometer. The launch site was Prince Albert, Saskatchewan, Canada. The balloon flew at an average atmospheric depth of 4.7 g cm-2 for more than 22 hr. During this period a sample of 4.2 × 104 helium nuclei was gathered. No antihelium candidates were found in this sample. The resultant upper limit for the ratio of antihelium to helium in cosmic rays over the rigidity interval from 1 to 25 GV/c is 9 × 10-5 at 95% confidence.

This limit is below the predicted level, assuming equal matter and antimatter in the extragalactic cosmic rays.

Export citation and abstract BibTeX RIS

Please wait… references are loading.
10.1086/303886