Astronomy and Astrophysics
Context. Primary cosmic rays experience multiple deflections in the non-uniform galactic and heliospheric magnetic fields which may generate anisotropies. Aims. A study of anisotropies in the energy range between 100 and 500 GeV is performed. This energy range is not yet well explored. Methods. The L3 detector at the CERN electron-positron collider, LEP, is used for a study of the angular distribution of atmospheric muons with energies above 20 GeV. This distribution is used to investigate the isotropy of the time-dependent intensity of the primary cosmic-ray flux with a Fourier analysis. Results. A small deviation from isotropy at energies around 200 GeV is observed for the second harmonics at the solar frequency. No sidereal anisotropy is found at a level above 10ˉ⁴. The measurements were performed in the years 1999 and 2000.
Baksay, G; Baksay, L; Dehmelt, K; Hohlmann, M; Szillasi, Z; Vodopianov, I; and The L3 Collaboration, "Study Of The Solar Anisotropy Of Cosmic Ray Primaries Of About 200 GeV Energy With The L3+C Muon Detector" (2008). Aerospace, Physics, and Space Science Faculty Publications. 198.