Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Minimal energy configurations for charged particles on a thin conducting
  disc: the perimeter particles   The lowest energy configurations for N equal charged particles confined to a
thin conducting disc have been investigated in detail up to N=160 and in
outline for further values up to N=500. For all values of N up to 160 the
particle configurations can be described in terms of concentric shells. The
number of perimeter particles p appears to be simply related to N and to the
mean radius of the outermost internal shell. Justification for these relations
is obtained from a simple model based on the well-known distribution of
continuous charge on a conducting disc.

8
The categories of this paper are: hep-ex
16
The categories of this paper are: stat
12
The categories of this paper are: nucl-th
2
The categories of this paper are: math
33
The categories of this paper are: plasm-ph
11
The categories of this paper are: hep-lat
10
The categories of this paper are: q-bio
21
The categories of this paper are: adap-org
36
The categories of this paper are: cmp-lg
37
The categories of this paper are: supr-con
29
The categories of this paper are: funct-an
31
The categories of this paper are: ao-sci
6
The categories of this paper are: astro-ph
7
The categories of this paper are: hep-th
25
The categories of this paper are: patt-sol
13
The categories of this paper are: quant-ph