  Galactic cosmic rays are believed to be generated by diffusive shock
acceleration processes in Supernova Remnants, and the arrival direction is
likely determined by the distribution of their sources throughout the Galaxy,
in particular by the nearest and youngest ones. Transport to Earth through the
interstellar medium is expected to affect the cosmic ray properties as well.
However, the observed anisotropy of TeV cosmic rays and its energy dependence
cannot be explained with diffusion models of particle propagation in the
Galaxy. Within a distance of a few parsec, diffusion regime is not valid and
particles with energy below about 100 TeV must be influenced by the heliosphere
and its elongated tail. The observation of a highly significant localized
excess region of cosmic rays from the apparent direction of the downstream
interstellar flow at 1-10 TeV energies might provide the first experimental
evidence that the heliotail can affect the transport of energetic particles. In
particular, TeV cosmic rays propagating through the heliotail interact with the
100-300 AU wide magnetic field polarity domains generated by the 11 year
cycles. Since the strength of non-linear convective processes is expected to be
larger than viscous damping, the plasma in the heliotail is turbulent. Where
magnetic field domains converge on each other due to solar wind gradient,
stochastic magnetic reconnection likely occurs. Such processes may be efficient
enough to re-accelerate a fraction of TeV particles as long as scattering
processes are not strong. Therefore the fractional excess of TeV cosmic rays
from the narrow region toward the heliotail direction traces sightlines with
the lowest smearing scattering effects, that can also explain the observation
of a harder than average energy spectrum.
