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Progress in search for antihelium with bess
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Nozaki, M. Asoka, Y. Anraku, K. Fuke, H. Abe, K. Saeki, T. Fujikawa, M. Sasaki, M. Imori, M. Matsumoto, H. |
| Copyright Year | 2002 |
| Description | We have searched for antihelium nuclei in cosmic rays using the data obtained from balloon flights of the BESS magnetic spectrometer. The search was mainly based on track-quality selection, followed by rigidity analysis, and on the time-of-flight and dE/dx measurements by the scintillation counter hodoscope. We analysed all the data collected during 1993-2000 with a common analysis procedure. No antihelium nuclei events were found in the energy range from 1 to 14 GV. In order to determine a new upper limit, we have simulated the loss in the air and in the instrument of He (He-bar) using the GEANT/GHEISHA code. Combined with the data collected in 1993 through 2000, a new 95 % confidence upper limit for the ratio of He-bar/He at the top of the atmosphere of 6.8 x 10(exp -7) has been obtained to be after correcting for the interactions in the air and in the instruments. |
| File Size | 430906 |
| Page Count | 6 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_20030022694 |
| Archival Resource Key | ark:/13960/t0gv0jq18 |
| Language | English |
| Publisher Date | 2002-12-09 |
| Access Restriction | Open |
| Subject Keyword | Geophysics Hodoscopes Active Galactic Nuclei Progress Losses Scintillation Counters Data Acquisition Magnetic Spectroscopy Helium Correction Balloon Flight Cosmic Rays Confidence Limits Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Article |
