Chiral Extrapolation of the Sigma Resonance

Abstract

We analyze recent results on isoscalar $\pi\pi$ scattering from a $N_f=2+1$ lattice simulation by the HadronSpectrum collaboration by re-summing the two-flavor chiral scattering amplitude of the next-to-leading order in the so-called inverse amplitude method. The lattice data can be well extrapolated to the physical pion mass. We also find that both $I=0$ and $I=1$ lattice data can be described simultaneously for pion masses up to $M_{\pi}=236$ MeV.