title: New constraints from haverah park data on the photon and iron fluxes of ultrahigh-energy cosmic rays
abstract: Using data from inclined events ( 60 degrees <straight theta<80 degrees ) recorded by the Haverah Park shower detector, we show that above 10(19) eV less than 41% ( 54%) of the primary cosmic rays can be photons (iron nuclei) at the 95% confidence level. Above 4x10(19) eV less than 65% 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. Details of two new events above 10(20) eV are reported.
authors.affiliation: Departamento de Fisica de Particulas, Universidad de Santiago, 15706 Santiago de Compostela, Spain.
authors.initials: M
authors.lastname: Ave
authors.initials: JA
authors.lastname: Hinton
authors.initials: RA
authors.lastname: Vazquez
authors.initials: AA
authors.lastname: Watson
authors.initials: E
authors.lastname: Zas