Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Short- and long-distance contributions to the rare decay K_L-->mu+ mu-   The interplay between short- and long-distance contributions to the K_L-->mu+
mu- decay amplitude is analyzed. The long-distance piece is estimated using
chiral perturbation theory techniques and large-N_C considerations, leading to
a consistent description of the pi^0-->e+ e-, eta-->mu+ mu- and K_L-->mu+ mu-
branching ratios.

5
The categories of this paper are: gr-qc
1
The categories of this paper are: cs
19
The categories of this paper are: eess
3
The categories of this paper are: physics
12
The categories of this paper are: nucl-th
23
The categories of this paper are: solv-int
13
The categories of this paper are: quant-ph
26
The categories of this paper are: bayes-an
36
The categories of this paper are: cmp-lg
28
The categories of this paper are: alg-geom
10
The categories of this paper are: q-bio
11
The categories of this paper are: hep-lat
2
The categories of this paper are: math
27
The categories of this paper are: comp-gas
6
The categories of this paper are: astro-ph
20
The categories of this paper are: acc-phys