Dark matter (DM) is a big mystery in cosmic-ray and gamma-ray astrophysics. SUSY DM models together with cosmic-ray propagation model show DM can result in a spectral excess of cosmic-ray particles that comes from SUSY DM annihilation. Because of the specific spectral profile, antiprotons are a powerful tool identify and test DM models. It is well known that any balloon experiment for this purpose needs to consider the correction of atmospheric antiprotons which are produced by cosmic rays interacting with the atmospheric nuclei. We establish a Monte Carlo model, able to delicately calculate atmospheric antiproton flux in the Earth environment. Our results show the atmospheric correction is always required, even for space experiments, which originally proposed to measure antiproton flux without Earth contribution. Our study shows the antiproton flux at terrestrial level is significant for the purpose to test cosmic-ray transport model in the Earth environment.

Recent observation on SNR RX J1713.7-3946 by HESS with good resolution provides the opportunity of re-investigating the TeV-band gamma-ray emission. We have employed HEP event generator to establish a full picture of cosmic-ray interactions. Our study suggests the TeV-band gamma-ray emission of RX J1713.7-3946 is caused by shock-accelerated hadronic cosmic rays. This scenario implies a very high efficacy of particle acceleration, so the particle spectrum is expected to continuously harden toward high energies on account of cosmic-ray modification of the shock.

With the same approach, we also calculate the radio synchrotron radiation produced by secondary electrons in RX J1713.7-3946. We find that the multi-mG fields recently invoked to explain the X-ray flux variations are unlikely to extend over a large fraction of the radio- emitting region, otherwise the spectrum of hadronic cosmic rays in the energy window 0.1–100 GeV must be unusually hard.

We finally calculate the neutrino flux from high-energy gamma-ray sources such as RX J1713.7-3946, Vela Jr. and MGRO J2019+37. We conclude that, at about 10 TeV neutrino energy, an accumulation of data over about 5–10 years would allow to test the origin of TeV gamma-rays.