Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Differential cross section measurement of eta photoproduction on the
  proton from threshold to 1100 MeV   The differential cross section for the reaction p(gamma, eta p) has been
measured from threshold to 1100 MeV photon laboratory energy. For the first
time, the region of the S11(1535) resonance is fully covered in a
photoproduction experiment and allows a precise extraction of its parameters at
the photon point. Above 1000 MeV, S-wave dominance vanishes while a P-wave
contribution is observed whose nature will have to be clarified. These high
precision data together with the already measured beam asymmetry data will
provide stringent constraints on the extraction of new couplings of baryon
resonances to the eta meson.

19
The categories of this paper are: eess
22
The categories of this paper are: chao-dyn
31
The categories of this paper are: ao-sci
7
The categories of this paper are: hep-th
5
The categories of this paper are: gr-qc
28
The categories of this paper are: alg-geom
25
The categories of this paper are: patt-sol
3
The categories of this paper are: physics
12
The categories of this paper are: nucl-th
11
The categories of this paper are: hep-lat
18
The categories of this paper are: econ
10
The categories of this paper are: q-bio
2
The categories of this paper are: math
1
The categories of this paper are: cs
29
The categories of this paper are: funct-an
6
The categories of this paper are: astro-ph