Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The shape of the nucleon   We show that all four of the nucleon form factors can be very well explained
using the manifestly covariant spectator theory. The nucleon is modeled as a
spherical state of three constituent quarks with electromagnetic form factors,
all determined by the fit to the data.

1
The categories of this paper are: cs
28
The categories of this paper are: alg-geom
36
The categories of this paper are: cmp-lg
22
The categories of this paper are: chao-dyn
34
The categories of this paper are: chem-ph
19
The categories of this paper are: eess
18
The categories of this paper are: econ
7
The categories of this paper are: hep-th
37
The categories of this paper are: supr-con
15
The categories of this paper are: nucl-ex
31
The categories of this paper are: ao-sci
4
The categories of this paper are: cond-mat
10
The categories of this paper are: q-bio
23
The categories of this paper are: solv-int
2
The categories of this paper are: math
33
The categories of this paper are: plasm-ph