Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Analysis and interpretation of new low-energy Pi-Pi scattering data   The recently published E865 data on charged K_e4 decays and Pi-Pi phases are
reanalyzed to extract values of the two S-wave scattering lengths, of the
subthreshold parameters alpha and beta, of the low-energy constants l3-bar and
l4-bar as well as of the main two-flavour order parameters: <u-bar u> and F_pi
in the limit m_u = m_d = 0 taken at the physical value of the strange quark
mass. Our analysis is exclusively based on direct experimental information on
Pi-Pi phases below 800 MeV and on the new solutions of the Roy equations by
Ananthanarayan et al. The result is compared with the theoretical prediction
relating 2 a_0^0 - 5 a_0^2 and the scalar radius of the pion, which was
obtained in two-loop Chiral Perturbation Theory. A discrepancy at the 1-sigma
level is found and commented upon.

17
The categories of this paper are: q-fin
20
The categories of this paper are: acc-phys
34
The categories of this paper are: chem-ph
13
The categories of this paper are: quant-ph
4
The categories of this paper are: cond-mat
21
The categories of this paper are: adap-org
3
The categories of this paper are: physics
22
The categories of this paper are: chao-dyn
18
The categories of this paper are: econ
25
The categories of this paper are: patt-sol
10
The categories of this paper are: q-bio
28
The categories of this paper are: alg-geom
26
The categories of this paper are: bayes-an
29
The categories of this paper are: funct-an
6
The categories of this paper are: astro-ph
2
The categories of this paper are: math