Ultrahigh-energy Cosmic-ray Nuclei from Black Hole Jets: Recycling
  Galactic Cosmic Rays through Shear Acceleration
  We perform Monte Carlo simulations of transrelativistic shear acceleration
dedicated to a jet-cocoon system of active galactic nuclei. A certain fraction
of galactic cosmic rays in a halo is entrained, and sufficiently high-energy
particles can be injected to the reacceleration process and further accelerated
up to 100 EeV. We show that the shear reacceleration mechanism leads to a hard
spectrum of escaping cosmic rays, $dL_E/dE\propto E^{-1}-E^0$, distinct from a
conventional $E^{-2}$ spectrum. The supersolar abundance of ultrahigh-energy
nuclei is achieved due to injections at TeV-PeV energies. As a result, we find
that the highest-energy spectrum and mass composition can be reasonably
explained by our model without contradictions with the anisotropy data.
