2001/10/29 by M. Ave, J. A. Hinton, R. A. Vázquez +4 · 2 citations
Physics and Astronomy · #Air shower #Astrophysics #Astrophysics and Cosmic Phenomena #Cosmic ray #Dark Matter and Cosmic Phenomena #Energy (signal processing) #Flux (metallurgy) #Muon #Nuclear physics #Optics #Particle physics theoretical and experimental studies #Photon #Physics #Shower #Ultra-high-energy cosmic ray #astro-ph
paper · pdf · doi:10.1103/physrevd.65.063007
published as Phys.Rev. D65 (2002) 063007 · 45 pages, 25 figures
arxiv created 2001/10/29 · openalex publication_date 2002/03/04 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We describe a method to analyze inclined air showers produced by ultrahigh-energy cosmic rays using an analytical description of the muon densities. We report the results obtained using data from inclined events (60\ifmmode^∘\else\textdegree\fi<\ensuremathθ<80\ifmmode^∘\else\textdegree\fi) recorded by the Haverah Park shower detector for energies above 1019 eV. Using mass independent knowledge of the UHECR spectrum obtained from vertical air shower measurements and comparing the expected horizontal shower rate to the reported measurements we show that above 1019 eV less than 48% of the primary cosmic rays can be photons at the 95% confidence level and above 4\ifmmode×\else\texttimes\fi1019 eV less than 50% of the cosmic rays can be photonic at the same confidence level. These limits place important constraints on some models of the origin of ultrahigh-energy cosmic rays.