  Recent data on Galactic cosmic-ray (CR) leptons and hadrons gave rise to two
exciting problems: on the lepton side, the origin of the rise of the CR
positron fraction e+/(e- + e+) at ~10 - 300 GeV of energy; on the hadron side,
the nature of the spectral hardening observed in CR protons and nuclei at ~TeV
energies. The lepton anomaly indicates the existence of a nearby e+/- source.
It has been proposed that high-energy positrons can be produced inside nearby
supernova remnants (SNRs) via interactions of CR hadrons with the ambient
medium. A distinctive prediction of this mechanism is a high-energy rise of the
boron-to-carbon ratio, which has not been observed. It also requires old SNRs
at work (with ineffective magnetic field amplification and slow shock speed),
that cannot account for the CR hadronic spectra observed up to the knee
energies (~5 PeV). We propose a new picture where, in addition to such a nearby
CR accelerator, the high-energy spectrum of CR hadrons is provided by the
large-scale population of SNRs, on average younger, that can efficiently
accelerate CRs up to the knee. Under this scenario, the spectral hardening of
CR hadrons can be naturally interpreted as the transition between the two
components. As we will show, our two-component model breaks the connection
between the positron fraction and the boron-to-carbon ratio, which is now
predicted to decrease with energy in accordance with the data. Forthcoming data
from AMS will be crucial for testing this model.
