Author/Authors :
HEGRA Collaboration، نويسنده , , Christoph A. Karle، نويسنده , , S. Martinez، نويسنده , , R. Plaga، نويسنده , , F. Arqueros a، نويسنده , , K.H. Becker، نويسنده , , S.M. Bradbury، نويسنده , , J. Fernandez، نويسنده , , P. Fernandez، نويسنده , , V. Fonseca، نويسنده , , B. Funk، نويسنده , , V. Haustein، نويسنده , , G. Heinzelmann، نويسنده , , V. Henke، نويسنده , , H. Krawczynski، نويسنده , , F. Krennrich، نويسنده , , M. Kühn، نويسنده , , A. Lindner، نويسنده , , E. Lorenz a، نويسنده , , N. Magnussen، نويسنده , , et al.، نويسنده ,
Abstract :
Electromagnetic energy injected into the universe above a few hundred TeV is expected to pile up as γ radiation in a relatively narrow energy interval below 100 TeV due to its interaction with the 2.7°K background radiation. We present an upper limit (90% C.L.) on the ratio of primary γ to charged cosmic rays in the energy interval 65–160 TeV (80–200 TeV) of 10.3 · 10−3 (7.8 · 10−3). Data from the HEGRA cosmic-ray detector complex consisting of a wide angle Čerenkov array (AIROBICC) measuring the lateral distribution of air Čerenkov light and a scintillator array, were used with a novel method to discriminate γ-ray and hadron induced air showers. If the presently unmeasured universal far infrared background radiation is not too intense, the result rules out a topological-defect origin of ultrahigh energy cosmic rays for masses of the X particle released by the defects equal to or larger than about 1016 GeV.
