Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Cosmic-ray muon spectrum up to 20 TeV at 89/sup 0/ zenith angle

Journal Article · · Phys. Rev. D; (United States)
The 800-ton cosmic-ray spectrograph (MUTRON) has been used to measure the sea-level energy spectrum of cosmic-ray muons arriving from 86/sup 0/ to 90/sup 0/ zenith angles in the momentum region of 100--20 000 GeV/c. The measured muon energy spectrum can be interpreted by using a cosmic-ray primary spectrum of (1.80 cm/sup -2/sec/sup -1/ sr/sup -1/ GeV/sup -1/ E/sup -2.70/ DE) (E in GeV) and a scaling model incorporating an increasing interaction cross section for meson production in hadron-hadron interaction. The muon charge ratio at energies up to 15 TeV in the same zenith-angle range has been measured. It shows a small enhancement with increasing energy. By combining both results we may conclude that the cosmic-ray primary particle composition stays the same up to about 100 TeV as that obtained by direct measurements in the energy range below 1 TeV.
Research Organization:
Institute for Cosmic Ray Research, University of Tokyo, Tanashi, Tokyo 188, Japan
OSTI ID:
5144089
Journal Information:
Phys. Rev. D; (United States), Journal Name: Phys. Rev. D; (United States) Vol. 29:1; ISSN PRVDA
Country of Publication:
United States
Language:
English