Speaker
Description
Various models were proposed to explain the observed spectrum and composition of ultra-high-energy cosmic rays (UHECRs), but they remain inconclusive in constraining their source of origin. A significant neutrino event with an estimated energy between 72 PeV and 2.6 EeV was recently observed by the KM3NeT experiment (henceforth referred to as KM3-230213A). When interpreted as cosmogenic in origin, this event can provide constraints on the models of UHECRs.
In this contribution, we aim to constrain a two-population model of UHECRs using the cosmic-ray data of the Pierre Auger Observatory and KM3-230213A. The first population is mixed in composition, while the second population is comprised of ultra-high-energy (UHE) protons with a higher maximum rigidity. We present the parameter ranges around the best-fit solution to the spectrum and composition of UHECRs that is consistent with the detection of a single neutrino event by the KM3NeT detector at the energy range of KM3-230213A. This leads to constraints on the fraction of protons in UHECRs and the source evolution with redshift. Preliminary results indicate that a population of UHE protons with a strong source evolution (similar to the evolution of high-luminosity active galactic nuclei) is favored.
