Testing the Correlation of Ultra-High Energy Cosmic Rays with High   Redshift Sources
  We study the correlation between compact radio quasars or 3EG gamma-ray blazars and the arrival directions of cosmic rays above 10^19 eV using an updated list of air shower detections. Our Monte Carlo simulations reveal no significant correlations above random and some previous positive results appear to be an effect of the small sample size. Consequently, unless somehow severely deflected, there is no evidence for ultra-high energy cosmic ray primaries being new particles or particles with new interactions beyond the electroweak scale, produced in high-redshift active galactic nuclei. 
Guenter Sigl (1), Diego Torres (2), Luis Anchordoqui (3), Gustavo   Romero (2) ((1) CNRS, Institut d'Astrophysique de Paris,...