Neutrinos: the key to ultrahigh energy cosmic rays

Phys Rev Lett. 2005 Sep 30;95(14):141101. doi: 10.1103/PhysRevLett.95.141101. Epub 2005 Sep 29.


Observations of ultrahigh energy cosmic rays (UHECR) do not uniquely determine both the injection spectrum and the evolution model for UHECR sources--primarily because interactions during propagation obscure the early Universe from direct observation. Detection of neutrinos produced in those same interactions, coupled with UHECR results, would provide a full description of UHECR source properties.