Turbulent diffusion and drift in galactic magnetic fields and the explanation of the knee in the cosmic ray spectrum

Abstract

We reconsider the scenario in which the knee in the cosmic ray spectrum is explained as due to a change in the escape mechanism of cosmic rays from the Galaxy from one dominated by transverse diffusion to one dominated by drifts. We solve the diffusion equations adopting realistic galactic field models and using diffusion coefficients appropriate for strong turbulence (with a Kolmogorov spectrum of fluctuations) and consistent with the assumed magnetic fields. We show that properly taking into account these effects leads to a natural explanation of the knee in the spectrum, and a transition towards a heavier composition above the knee is predicted.

17 pp., 6 figures; revised version with minor changes. To appear in JHEP

References in corpus (5)

• Transport of Cosmic Rays in Chaotic Magnetic Fields
• A Measurement of the Cosmic Ray Spectrum and Composition at the Knee
• Acceleration of Particles by Oblique Shocks and Cosmic Ray Spectra around the Knee Region
• The Composition of Cosmic Rays at the Knee
• Cosmic ray photodisintegration and the knee of the spectrum

Cited by in corpus (28)

• KASCADE measurements of energy spectra for elemental groups of cosmic rays: Results and open problems
• Cosmic-Ray Nuclei, Antiprotons and Gamma-rays in the Galaxy: a New Diffusion Model
• The all-particle spectrum of primary cosmic rays in the wide energy range from 10^14 eV to 10^17 eV observed with the Tibet-III air-shower array
• Models of the Knee in the Energy Spectrum of Cosmic Rays
• Cosmic Neutrino Pevatrons: A Brand New Pathway to Astronomy, Astrophysics, and Particle Physics
• Diffusion and drift of cosmic rays in highly turbulent magnetic fields
• Extragalactic UHE proton spectrum and prediction for iron-nuclei flux at 10^8 - 10^9 GeV
• Cosmic ray spectrum and anisotropies from the knee to the second knee
• Cosmic Ray Models
• Escape model for Galactic cosmic rays and an early extragalactic transition
• Progress in high-energy cosmic ray physics
• Shower Power: Isolating the Prompt Atmospheric Neutrino Flux Using Electron Neutrinos
• Neutrino yield from Galactic cosmic rays
• Explaining the Spectra of Cosmic Ray Groups above the Knee by Escape from the Galaxy
• Diffuse Neutrino and Gamma-ray Emissions of the Galaxy above the TeV
• Vela as the Source of Galactic Cosmic Rays above 100 TeV
• Cosmic ray drift, the second knee and galactic anisotropies
• LHAASO sensitivity for diffuse gamma-ray signals from the Galaxy
• Rigidity dependent knee and cosmic ray induced high energy neutrino fluxes
• Estimates of multipolar coefficients to search for cosmic ray anisotropies with non-uniform or partial sky coverage
• Cosmic Ray Energy Spectra and Mass Composition at the Knee - Recent Results from KASCADE -
• Detectable neutrino fluxes due to enhanced cosmic ray densities in the Galactic Center region
• A scenario for the Galactic cosmic rays between the knee and the second-knee
• Energy dependence of the knee in the cosmic ray spectrum across the Milky Way
• Reconciling the light component and all-particle cosmic ray energy spectra at the knee
• Progenitor model of Cosmic Ray knee
• Joint constraint on the propagation origin of the cosmic-ray spectral knee from energy spectrum and anisotropy observations
• Accelerated protons produced by magnetic Penrose process in Sgr A*