ZhETF, Vol. 144,
p. 1153 (December 2013)
(English translation - JETP,
Vol. 117, No. 6,
available online at www.springer.com
ESTIMATE OF THE FRACTION OF PRIMARY PHOTONS IN THE COSMIC-RAY FLUX AT ENERGIES eV FROM THE EAS-MSU EXPERIMENT DATA
Fomin Yu.A., Kalmykov N.N., Kulikov G.V., Sulakov V.P., Troitsky S.V.
Received: May 27, 2013
We reanalyze archival EAS-MSU data in order to search for events with an anomalously low content of muons with energies Eμ. We confirm the first evidence for a nonzero flux of primary cosmic gamma rays at energies eV. The estimated fraction of primary gamma rays in the flux of cosmic particles with energies eV is %, which corresponds to the intensity . The study of arrival directions does not favor any particular mechanism of the origin of the photon-like events.