New Constraints from Haverah Park Data on the Photon and Iron Fluxes of Ultrahigh-Energy Cosmic Rays

Using data from inclined events ( 60^∘<θ<80^∘) recorded by the Haverah Park shower detector, we show that above 10¹⁹eV less than $41%$ ( $54%$) of the primary cosmic rays can be photons (iron nuclei) at the $95%$ confidence level. Above 4×10¹⁹eV 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 10²⁰eV are reported.