Interpretation of the excess of antiparticles within a modified paradigm of galactic cosmic rays

Abstract

We argue that the anomalously high fluxes of positrons and antiprotons found in cosmic rays (CR) can be satisfactorily explained by introducing two additional elements to the current "standard" 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 (close to $FI\propto E^{-2.3}$) and (2) hard ($FII\propto E^{-1.8}$ or harder), energy distributions. Assuming that CRs in the 2nd population of accelerators accumulate "grammage" of the order of $1g/c{\mathrm{m}}^2$ before their leakage 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 above 200 GV. The 2nd source population accelerating CRs with a rate at the level below 10 percent of the power of the 1st source population, can be responsible for the highest energy protons and nuclei of Galactic CRs up to the "knee" around $10^{15}\mathrm{eV}$.

accepted for publication in PRD

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Cited by in corpus (15)

• Measurement of ultra-high-energy diffuse gamma-ray emission of the Galactic plane from 10 TeV to 1 PeV with LHAASO-KM2A
• Combined analysis of AMS-02 (Li,Be,B)/C, N/O, 3He, and 4He data
• Galactic diffuse gamma-ray emission from GeV to PeV energies in light of up-to-date cosmic ray measurements
• Measurement of Very-high-energy Diffuse Gamma-ray Emissions from the Galactic Plane with LHAASO-WCDA
• Interpretations of the cosmic ray secondary-to-primary ratios measured by DAMPE
• Ultrahigh-energy diffuse gamma-ray emission from cosmic-ray interactions with medium surrounding acceleration sources
• Evidence of fresh cosmic ray in galactic plane based on DAMPE measurement of B/C and B/O ratios
• Some new hints on cosmic-ray propagation from AMS-02 nuclei spectra
• Implications of a Possible Spectral Structure of Cosmic-ray Protons Unveiled by the DAMPE
• A hard spectrum diffuse gamma-ray component associated with HII gas in the Galactic plane
• Origin of hardening in spectra of cosmic ray nuclei at a few hundred GeV using AMS-02 data
• Secondary cosmic-ray nuclei in the Galactic halo model with nonlinear Landau damping
• Examining the secondary product origin of cosmic ray positrons with the latest AMS-02 data
• Direct measurements of cosmic rays and their possible interpretations
• Cosmic-ray deuteron excess from a primary component