Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Charge symmetry breaking and the d d -> alpha pi0 reaction -- recent
  theoretical developments   The status of the theoretical effort to calculate charge-symmetry-breaking
pion production reactions will be presented. The main emphasis will be on the d
d -> alpha pi0 reaction, especially in relation to the recent IUCF experiment.
Suggestions for future theoretical and experimental work will be made.

28
The categories of this paper are: alg-geom
7
The categories of this paper are: hep-th
20
The categories of this paper are: acc-phys
34
The categories of this paper are: chem-ph
37
The categories of this paper are: supr-con
8
The categories of this paper are: hep-ex
5
The categories of this paper are: gr-qc
13
The categories of this paper are: quant-ph
26
The categories of this paper are: bayes-an
29
The categories of this paper are: funct-an
32
The categories of this paper are: atom-ph
36
The categories of this paper are: cmp-lg
18
The categories of this paper are: econ
31
The categories of this paper are: ao-sci
11
The categories of this paper are: hep-lat
15
The categories of this paper are: nucl-ex