Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Magnetic diffusion effects on the Ultra-High Energy Cosmic Ray spectrum
  and composition   We discuss the effects of diffusion of high energy cosmic rays in turbulent
extra-galactic magnetic fields. We find an approximate expression for the low
energy suppression of the spectrum of the different mass components (with
charge $Z$) in the case in which this suppression happens at energies below
$\sim Z$ EeV, so that energy losses are dominated by the adiabatic ones.
  The low energy suppression appears when cosmic rays from the closest sources
take a time comparable to the age of the Universe to reach the Earth. This
occurs for energies $E< Z\, {\rm EeV}\,(B/{{\rm G}})\sqrt{l_c/{\rm
Mpc}}(d_s/70\ {\rm Mpc})$ in terms of the magnetic field RMS strength $B$, its
coherence length $l_c$ and the typical separation between sources $d_s$.
  We apply this to scenarios in which the sources produce a mixed composition
and have a relatively low maximum rigidity ($E_{max}\sim (2$--$10) Z $ EeV),
finding that diffusion has a significant effect on the resulting spectrum, the
average mass and on its spread, in particular reducing this last one. For
reasonable values of $B$ and $l_c$ these effects can help to reproduce the
composition trends observed by the Auger Collaboration for source spectra
compatible with Fermi acceleration.

20
The categories of this paper are: acc-phys
26
The categories of this paper are: bayes-an
11
The categories of this paper are: hep-lat
7
The categories of this paper are: hep-th
35
The categories of this paper are: mtrl-th
17
The categories of this paper are: q-fin
2
The categories of this paper are: math
19
The categories of this paper are: eess
3
The categories of this paper are: physics
28
The categories of this paper are: alg-geom
4
The categories of this paper are: cond-mat
12
The categories of this paper are: nucl-th
18
The categories of this paper are: econ
14
The categories of this paper are: math-ph
32
The categories of this paper are: atom-ph
33
The categories of this paper are: plasm-ph