Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Photodisintegration of cosmic ray nuclei in galaxies and galaxy cluster
  radiation fields   We present the results of a new calculation for the photodisintegration of
ultra-high energy cosmic ray nuclei on soft photon targets. We include all the
relevant photodisintegraton processes i.e giant dipole resonance,
quasi-deuteron, baryonic resonances and photofragmentation. In particular, for
the giant dipole process we use a recent calculation of the giant dipole cross
section. We calculate the mean free path for photodisintegration processes for
radiation fields that are likely to exist within galaxies and clusters of
galaxies.

25
The categories of this paper are: patt-sol
30
The categories of this paper are: q-alg
24
The categories of this paper are: dg-ga
10
The categories of this paper are: q-bio
31
The categories of this paper are: ao-sci
29
The categories of this paper are: funct-an
4
The categories of this paper are: cond-mat
13
The categories of this paper are: quant-ph
5
The categories of this paper are: gr-qc
37
The categories of this paper are: supr-con
21
The categories of this paper are: adap-org
7
The categories of this paper are: hep-th
20
The categories of this paper are: acc-phys
2
The categories of this paper are: math
17
The categories of this paper are: q-fin
11
The categories of this paper are: hep-lat