Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Collective Dipole Oscillations in Atomic Nuclei and Small Metal
  Particles   (The systematics of photon absorption cross sections in nuclei and small
metal particles are examined as a function of the number of constituent
fermions $A$. It is pointed out that the shell-structure-linked oscillations in
the full width at half maximum (FWHM) of the photoneutron cross section in
nuclei, earlier recognized for $A > 63$, in fact persist down to the lightest
nuclei. Averaging over the oscillations or focusing on the lower envelope of
the oscillating curve (magic nuclei), the FWHM is seen to generally decrease
with increasing $A$, consistent with $A^{-1/3}$, a dependence which was earlier
known to hold in metal particle systems. If the FWHMs are scaled by the
respective Fermi energies and the inverse radii by the Fermi wave vectors, the
two data sets become comparable in magnitude. A schematic theoretical
description of the systematics is presented.)

24
The categories of this paper are: dg-ga
19
The categories of this paper are: eess
16
The categories of this paper are: stat
28
The categories of this paper are: alg-geom
21
The categories of this paper are: adap-org
15
The categories of this paper are: nucl-ex
2
The categories of this paper are: math
17
The categories of this paper are: q-fin
34
The categories of this paper are: chem-ph
31
The categories of this paper are: ao-sci
0
The categories of this paper are: hep-ph
25
The categories of this paper are: patt-sol
1
The categories of this paper are: cs
29
The categories of this paper are: funct-an
3
The categories of this paper are: physics
26
The categories of this paper are: bayes-an