Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Fermion scattering amplitudes from gauge-invariant actions for open
  superstring field theory
12
The categories of this paper are: nucl-th
20
The categories of this paper are: acc-phys
17
The categories of this paper are: q-fin
22
The categories of this paper are: chao-dyn
24
The categories of this paper are: dg-ga
28
The categories of this paper are: alg-geom
3
The categories of this paper are: physics
14
The categories of this paper are: math-ph
4
The categories of this paper are: cond-mat
21
The categories of this paper are: adap-org
1
The categories of this paper are: cs
10
The categories of this paper are: q-bio
8
The categories of this paper are: hep-ex
19
The categories of this paper are: eess
2
The categories of this paper are: math
18
The categories of this paper are: econ