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Title: Upper limit on the ultrahigh-energy photon flux from AGASA and Yakutsk data

Abstract

We present the interpretation of the muon and scintillation signals of ultrahigh-energy air showers observed by AGASA and Yakutsk extensive air shower array experiments. We consider case-by-case ten highest-energy events with known muon content and conclude that at the 95% confidence level none of them was induced by a primary photon. Taking into account statistical fluctuations and differences in the energy estimation of proton and photon primaries, we derive an upper limit of 36% at a 95% confidence level on the fraction of primary photons in the cosmic-ray flux above 10{sup 20} eV. This result disfavors the Z-burst and superheavy dark-matter solutions to the Greisen-Zatsepin-Kuzmin-cutoff problem.

Authors:
 [1];  [2];  [3];  [2]; ; ;  [4]; ; ; ;  [5]; ;  [1]
  1. Institute for Nuclear Research of the Russian Academy of Sciences, Moscow 117312 (Russian Federation)
  2. (Russian Federation)
  3. Faculty of Physics, M.V. Lomonosov Moscow State University, Moscow 119992 (Russian Federation)
  4. D.V. Skobeltsin Institute of Nuclear Physics, M.V. Lomonosov Moscow State University, Moscow 119992 (Russian Federation)
  5. Yu.G. Shafer Institute of Cosmophysical Research and Aeronomy, Yakutsk 677980 (Russian Federation)
Publication Date:
OSTI Identifier:
20782601
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. D, Particles Fields; Journal Volume: 73; Journal Issue: 6; Other Information: DOI: 10.1103/PhysRevD.73.063009; (c) 2006 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; COSMIC MUONS; COSMIC PHOTONS; COSMIC PROTONS; COSMIC RAY DETECTION; COSMIC RAY FLUX; EXTENSIVE AIR SHOWERS; FLUCTUATIONS; NONLUMINOUS MATTER

Citation Formats

Rubtsov, G.I., Faculty of Physics, M.V. Lomonosov Moscow State University, Moscow 119992, Dedenko, L.G., D.V. Skobeltsin Institute of Nuclear Physics, M.V. Lomonosov Moscow State University, Moscow 119992, Fedorova, G.F., Fedunin, E.Yu., Roganova, T.M., Glushkov, A.V., Makarov, I.T., Pravdin, M.I., Sleptsov, I.E., Gorbunov, D.S., and Troitsky, S.V.. Upper limit on the ultrahigh-energy photon flux from AGASA and Yakutsk data. United States: N. p., 2006. Web. doi:10.1103/PHYSREVD.73.063009.
Rubtsov, G.I., Faculty of Physics, M.V. Lomonosov Moscow State University, Moscow 119992, Dedenko, L.G., D.V. Skobeltsin Institute of Nuclear Physics, M.V. Lomonosov Moscow State University, Moscow 119992, Fedorova, G.F., Fedunin, E.Yu., Roganova, T.M., Glushkov, A.V., Makarov, I.T., Pravdin, M.I., Sleptsov, I.E., Gorbunov, D.S., & Troitsky, S.V.. Upper limit on the ultrahigh-energy photon flux from AGASA and Yakutsk data. United States. doi:10.1103/PHYSREVD.73.063009.
Rubtsov, G.I., Faculty of Physics, M.V. Lomonosov Moscow State University, Moscow 119992, Dedenko, L.G., D.V. Skobeltsin Institute of Nuclear Physics, M.V. Lomonosov Moscow State University, Moscow 119992, Fedorova, G.F., Fedunin, E.Yu., Roganova, T.M., Glushkov, A.V., Makarov, I.T., Pravdin, M.I., Sleptsov, I.E., Gorbunov, D.S., and Troitsky, S.V.. Wed . "Upper limit on the ultrahigh-energy photon flux from AGASA and Yakutsk data". United States. doi:10.1103/PHYSREVD.73.063009.
@article{osti_20782601,
title = {Upper limit on the ultrahigh-energy photon flux from AGASA and Yakutsk data},
author = {Rubtsov, G.I. and Faculty of Physics, M.V. Lomonosov Moscow State University, Moscow 119992 and Dedenko, L.G. and D.V. Skobeltsin Institute of Nuclear Physics, M.V. Lomonosov Moscow State University, Moscow 119992 and Fedorova, G.F. and Fedunin, E.Yu. and Roganova, T.M. and Glushkov, A.V. and Makarov, I.T. and Pravdin, M.I. and Sleptsov, I.E. and Gorbunov, D.S. and Troitsky, S.V.},
abstractNote = {We present the interpretation of the muon and scintillation signals of ultrahigh-energy air showers observed by AGASA and Yakutsk extensive air shower array experiments. We consider case-by-case ten highest-energy events with known muon content and conclude that at the 95% confidence level none of them was induced by a primary photon. Taking into account statistical fluctuations and differences in the energy estimation of proton and photon primaries, we derive an upper limit of 36% at a 95% confidence level on the fraction of primary photons in the cosmic-ray flux above 10{sup 20} eV. This result disfavors the Z-burst and superheavy dark-matter solutions to the Greisen-Zatsepin-Kuzmin-cutoff problem.},
doi = {10.1103/PHYSREVD.73.063009},
journal = {Physical Review. D, Particles Fields},
number = 6,
volume = 73,
place = {United States},
year = {Wed Mar 15 00:00:00 EST 2006},
month = {Wed Mar 15 00:00:00 EST 2006}
}
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