Penn State Finds Ultraheavy Nuclei Reach Earth with Extreme Energy

Penn State scientists are proposing an unexpected component for the most energetic particles in the universe: atomic nuclei heavier than iron. Their work, published in Physical Review Letters, addresses the mystery surrounding ultrahigh-energy cosmic rays like the Amaterasu particle detected in 2021, an event comparable in energy to the Oh-My-God particle detected in 1991 but with an uncertain origin. The team’s calculations demonstrate that these ultraheavy nuclei lose energy more slowly during intergalactic travel, potentially…