Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Nucleon and Hyperon Resonances with the Crystal Ball   The Crystal Ball Spectrometer is being used at Brookhaven National Laboratory
in a series of experiments which study all neutral final states of pi-p and K-p
induced reactions. We report about the experimental setup and progress in
obtaining new results for the radiative capture reactions pi-p-->gn and
K-p-->gL,charge exchange pi-p-->pi0n,two pi0 production pi-p-->pi0pi0n, and eta
production pi-p-->eta n reactions. Data have also been obtained on the decays
of N*, Delta, Lambda, and Sigma resonances. Threshold eta production has been
studied in detail for both pi-p and K-p. Sequential resonance decays have been
investigated bystudying the 2pi0 production mechanism both in the fundamental
interaction and in nuclei. In addition, we have used the etas produced near
threshold to make precision measurements searching in particular for rare and
forbidden eta decays.

18
The categories of this paper are: econ
28
The categories of this paper are: alg-geom
23
The categories of this paper are: solv-int
25
The categories of this paper are: patt-sol
10
The categories of this paper are: q-bio
5
The categories of this paper are: gr-qc
3
The categories of this paper are: physics
7
The categories of this paper are: hep-th
4
The categories of this paper are: cond-mat
36
The categories of this paper are: cmp-lg
29
The categories of this paper are: funct-an
31
The categories of this paper are: ao-sci
19
The categories of this paper are: eess
16
The categories of this paper are: stat
33
The categories of this paper are: plasm-ph
6
The categories of this paper are: astro-ph