Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Free-free transitions in a bichromatic field of frequencies $\omega $
  and $2\omega$ at moderate field intensities   Free-free transitions in laser-assisted electron-hydrogen scattering in a
bichromatic field of frequencies $\omega $ and $2\omega $ are studied at
moderate intensities for fast projectiles. A hybrid approach is used, in which
the field-projectile interaction is described exactly but the field-target one
is described by second order perturbation theory; the projectile-target
interaction is treated in the first Born approximation. The adopted description
of the target enables a consistent study of the leading process to each of the
considered sidebands. Numerical results are presented for the angular
distributions in a geometry and at frequencies for which the target dressing is
important. The influence of the relative phase between the fields is
investigated, too.

13
The categories of this paper are: quant-ph
22
The categories of this paper are: chao-dyn
11
The categories of this paper are: hep-lat
17
The categories of this paper are: q-fin
32
The categories of this paper are: atom-ph
23
The categories of this paper are: solv-int
26
The categories of this paper are: bayes-an
6
The categories of this paper are: astro-ph
4
The categories of this paper are: cond-mat
14
The categories of this paper are: math-ph
16
The categories of this paper are: stat
37
The categories of this paper are: supr-con
8
The categories of this paper are: hep-ex
27
The categories of this paper are: comp-gas
36
The categories of this paper are: cmp-lg
1
The categories of this paper are: cs