Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Narrow band emission from Au-film on Cu- substrate   The experiments reveal the strong narrow band in the spectra of the emission
from Au-film on the Cu substrate. The emission was excited by red He-Ne laser
in standard geometry for Raman back-scattering experiments. Some additional
experiments were made. The set of obtained data did not give enough arguments
to make the final conclusion about the nature of this emission. The details of
experiments, results, and possible explanations are discussed.

36
The categories of this paper are: cmp-lg
25
The categories of this paper are: patt-sol
26
The categories of this paper are: bayes-an
23
The categories of this paper are: solv-int
31
The categories of this paper are: ao-sci
28
The categories of this paper are: alg-geom
3
The categories of this paper are: physics
17
The categories of this paper are: q-fin
6
The categories of this paper are: astro-ph
1
The categories of this paper are: cs
24
The categories of this paper are: dg-ga
8
The categories of this paper are: hep-ex
0
The categories of this paper are: hep-ph
22
The categories of this paper are: chao-dyn
7
The categories of this paper are: hep-th
2
The categories of this paper are: math