Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Lattice study of pion-pion scattering using Nf=2+1 Wilson improved
  quarks with masses down to their physical values   We use 2HEX smeared gauge configurations generated with an
$\mathrm{N}_\mathrm{f}\mathrm{=2+1}$ clover improved Wilson action to
investigate $\pi\pi$ scattering in the $\rho$ channel. The range of lattice
spacings (0.054 to 0.12 fm) and space-like extents (32 and 48) allows us to
extract the scattering parameters through the volume dependence of the
$\pi\pi$-state energies according to L\"uscher's formalism. The pion masses
(134 to 300 MeV) are light enough to allow the decay of the rho and the level
repulsion observed indicates that our data are sensitive to the interaction. We
analyse our data with a multi-channel GEVP variational formula. Our results are
in good agreement with the experimental values and consistent with a weak pion
mass dependence of the $\rho\pi\pi$ coupling constant.

13
The categories of this paper are: quant-ph
26
The categories of this paper are: bayes-an
28
The categories of this paper are: alg-geom
34
The categories of this paper are: chem-ph
37
The categories of this paper are: supr-con
10
The categories of this paper are: q-bio
1
The categories of this paper are: cs
2
The categories of this paper are: math
32
The categories of this paper are: atom-ph
8
The categories of this paper are: hep-ex
20
The categories of this paper are: acc-phys
33
The categories of this paper are: plasm-ph
18
The categories of this paper are: econ
31
The categories of this paper are: ao-sci
5
The categories of this paper are: gr-qc
29
The categories of this paper are: funct-an