Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: First results from the OSQAR photon regeneration experiment: No light
  shining through a wall   A new method to amplify the photon-axion conversions in magnetic field is
proposed using a buffer gas at a specific pressure. As a first result, new
bounds for mass and coupling constant for purely laboratory experiments aiming
to detect any hypothetical scalars and pseudo-scalars which can couple to
photons were obtained at 95% confidence level, excluding the PVLAS result newly
disclaimed.

3
The categories of this paper are: physics
21
The categories of this paper are: adap-org
5
The categories of this paper are: gr-qc
33
The categories of this paper are: plasm-ph
35
The categories of this paper are: mtrl-th
32
The categories of this paper are: atom-ph
2
The categories of this paper are: math
27
The categories of this paper are: comp-gas
13
The categories of this paper are: quant-ph
22
The categories of this paper are: chao-dyn
37
The categories of this paper are: supr-con
26
The categories of this paper are: bayes-an
28
The categories of this paper are: alg-geom
10
The categories of this paper are: q-bio
31
The categories of this paper are: ao-sci
30
The categories of this paper are: q-alg