Interpretation of the "Excess" of Antiparticles within the Standard Cosmic Ray Paradigm with a Slight Modification

The anomalously high fluxes of positrons and antiprotons found in cosmic rays (CR) can be satisfactorily explained by introducing two new elements to the current paradigm of Galactic CRs. First, we propose that the antiparticles are effectively produced in interactions of primary CRs with the surrounding gas not only in the interstellar medium (ISM) but also inside the accelerators. Secondly, we postulate the existence of two source populations injecting CRs into the ISM with different, (1) soft ($FI \propto E^{-2.4}$) and (2) hard ($FII \propto E^{-1.9}$), energy distributions. With an additional assumption that CRs in the 2nd population of accelerators accumulate "grammage" of the order of $1 \ \rm g/cm^2$ before being injected into ISM, we can explain the energy distributions and absolute fluxes of both positrons and antiprotons, as well as the fluxes of secondary nuclei of the {Li,Be,B} group. The superposition of contributions of two source populations also explains the reported hardening of the spectra of CR protons and nuclei around 200 GeV/amu. The 2nd source population accelerating CRs with a rate at the level below 10 per cent of the power of the 1st source population, may consist of PeVatrons responsible for the highest energy particles in galactic CRs up to the "knee" around $10^{15} \ \rm eV$.