Possible Evidence for the Stochastic Acceleration of Secondary Antiprotons by Supernova Remnants

Abstract

The antiproton-to-proton ratio in the cosmic-ray spectrum is a sensitive probe of new physics. Using recent measurements of the cosmic-ray antiproton and proton fluxes in the energy range of 1-1000 GeV, we study the contribution to the $\bar{p}/p$ ratio from secondary antiprotons that are produced and subsequently accelerated within individual supernova remnants. We consider several well-motivated models for cosmic-ray propagation in the interstellar medium and marginalize our results over the uncertainties related to the antiproton production cross section and the time-, charge-, and energy-dependent effects of solar modulation. We find that the increase in the $\bar{p}/p$ ratio observed at rigidities above $\sim$ 100 GV cannot be accounted for within the context of conventional cosmic-ray propagation models, but is consistent with scenarios in which cosmic-ray antiprotons are produced and subsequently accelerated by shocks within a given supernova remnant. In light of this, the acceleration of secondary cosmic rays in supernova remnants is predicted to substantially contribute to the cosmic-ray positron spectrum, accounting for a significant fraction of the observed positron excess.

5 pages, 3 figures and 4 tables. Changes in v2: extended discussion on the method, title and some text revisions, all in agreement with final published PRD version. Results unchanged

References in corpus (18)

• A Theory of Dark Matter
• Exciting Dark Matter and the INTEGRAL/SPI 511 keV signal
• The origin of the positron excess in cosmic rays
• On possible interpretations of the high energy electron-positron spectrum measured by the Fermi Large Area Telescope
• Pulsars versus Dark Matter Interpretation of ATIC/PAMELA
• High-energy antiprotons from old supernova remnants
• Testing astrophysical models for the PAMELA positron excess with cosmic ray nuclei
• The galactic antiproton spectrum at high energies: background expectation vs. exotic contributions
• Updated cosmic-ray and radio constraints on light dark matter: Implications for the GeV gamma-ray excess at the Galactic center
• Production of Mesons and Baryons at High Rapidity and High Pt in Proton-Proton Collisions at sqrt(s) = 200 GeV
• What Does The PAMELA Antiproton Spectrum Tell Us About Dark Matter?
• New calculation of antiproton production by cosmic ray protons and nuclei
• The Role of Antimatter Searches in the Hunt for Supersymmetric Dark Matter
• The Cosmic Ray Antiproton Background for AMS-02
• Charge Asymmetric Cosmic Ray Signals From Dark Matter Decay
• Astrophysical Uncertainties in the Cosmic Ray Electron and Positron Spectrum From Annihilating Dark Matter
• Plus Charge Prevalence in Cosmic Rays: Room for Dark Matter in the Positron Spectrum
• B/C ratio and the PAMELA positron excess

Cited by in corpus (27)

• The origin of Galactic cosmic rays: challenges to the standard paradigm
• A Robust Excess in the Cosmic-Ray Antiproton Spectrum: Implications for Annihilating Dark Matter
• HAWC Observations Strongly Favor Pulsar Interpretations of the Cosmic-Ray Positron Excess
• Using HAWC to Discover Invisible Pulsars
• Constraining heavy dark matter with cosmic-ray antiprotons
• Where do the AMS-02 anti-helium events come from?
• The Return of the Templates: Revisiting the Galactic Center Excess with Multi-Messenger Observations
• Understanding the spectral hardenings and radial distribution of Galactic cosmic rays and Fermi diffuse gamma-rays with spatially-dependent propagation
• Combined analysis of AMS-02 (Li,Be,B)/C, N/O, 3He, and 4He data
• Revisit of cosmic ray antiprotons from dark matter annihilation with updated constraints on the background model from AMS-02 and collider data
• Hidden sector explanation of $B$-decay and cosmic ray anomalies
• Measuring the Local Diffusion Coefficient with H.E.S.S. Observations of Very High-Energy Electrons
• The Semi-Hooperon: Gamma-ray and anti-proton excesses in the Galactic Center
• Cosmic-Ray Positrons Strongly Constrain Leptophilic Dark Matter
• Features in the Spectrum of Cosmic-Ray Positrons from Pulsars
• Revisit cosmic ray propagation by using ${}^1$H, ${}^2$H, ${}^3$He and ${}^4$He
• Anti-Deuterons and Anti-Helium Nuclei from Annihilating Dark Matter
• Utilizing cosmic-ray positron and electron observations to probe the averaged properties of Milky Way pulsars
• Production and acceleration of antinuclei in supernova shockwaves
• $e^{+}$ and $\bar{p}$ production in $pp$ collisions and the cosmic-ray $e^{+}/\bar{p}$ flux ratio
• Revisiting GeV-scale annihilating dark matter with the AMS-02 positron fraction
• Constraining the Charge-, Time- and Rigidity-Dependence of Cosmic-Ray Solar Modulation with AMS-02 Observations during Solar Cycle 24
• Origin of hardening and universality of cosmic rays spectra in GV-PV rigidity region
• Observing Signals of Spectral Features in the Cosmic-Ray Positrons and Electrons from Milky Way Pulsars
• Possible counterpart signal of the Fermi bubbles at the cosmic-ray positrons
• Secondary antinuclei from supernova remnants and background for dark matter searches
• Diffusion of Cosmic Antiprotons Generated throughout the Dark Matter Halo -- A Semi-Analytical Solution for a Linear Galactic Wind Model