Speaker: Stephan Durr
I will review the (practical) convergence of the ChPT series (in the p regime).
In the SU(2) framework there is a number of new results, and
improved estimates of \bar\ell_3 and \bar\ell_4 can be given.
In the SU(3) framework very few new lattice computations are available and the
improvement in the precision of the low-energy constants L_i is
comparatively slow. I will sketch some of the convergence issues genuine
to extensions of the chiral framework which include additional sources of
chiral symmetry breaking (finite lattice spacing) and/or violations of
unitarity (different sea and valence quark masses). If time permits it
will be pointed out that the quark mass ratios m_u/m_d and m_s/m_d happen
to be such that no reorderings of the chiral series are needed.