Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Continuous Lyman-alpha generation by four-wave mixing in mercury for
  laser-cooling of antihydrogen   Cooling antihydrogen atoms is important for future experiments both to test
the fundamental CPT symmetry by high-resolution laser spectroscopy and also to
measure the gravitational acceleration of antimatter. Laser-cooling of
antihydrogen can be done on the strong 1S-2P transition at the wavelength of
Lyman-alpha (121.6nm). A continuous-wave laser at the Lyman-alpha wavelength
based on solid-state fundamental lasers is described. By using a two-photon and
a near one photon resonance a scan across the whole phasematching curve of the
four-wave mixing process is possible. Furthermore the influence of the beam
profile of one fundamental beam on the four-wave mixing process is studied.

17
The categories of this paper are: q-fin
30
The categories of this paper are: q-alg
36
The categories of this paper are: cmp-lg
35
The categories of this paper are: mtrl-th
21
The categories of this paper are: adap-org
12
The categories of this paper are: nucl-th
28
The categories of this paper are: alg-geom
23
The categories of this paper are: solv-int
18
The categories of this paper are: econ
19
The categories of this paper are: eess
11
The categories of this paper are: hep-lat
29
The categories of this paper are: funct-an
5
The categories of this paper are: gr-qc
4
The categories of this paper are: cond-mat
1
The categories of this paper are: cs
37
The categories of this paper are: supr-con