Local Flux of Low-Energy Antiprotons from Evaporating Primordial Black   Holes
  We investigate low-energy cosmic-ray antiprotons ($\bar{p}$'s) arising from the fragmentation of quarks and gluons emitted from evaporating primordial black holes (PBHs). To calculate the local interstellar flux of these $\bar{p}$'s, their propagation in the Galaxy is described by a 3-D Monte Carlo simulation based on the diffusion model. This flux is used with recent observations to derive new upper limits on (i) the local PBH explosion rate ${\cal R}<1.7\times10^{-2}$ pc$^{-3}$yr$^{-1}$, (ii) the fraction of the Universe's mass going into PBHs with particular mass, and (iii) the average density of PBHs in the Universe. 
K. Maki, T. Mitsui, and S. Orito (University of Tokyo)