Sigma resonance parameters from a $N_f=2$ lattice QCD simulation

Abstract

In this work we present the analysis of the energy spectrum from a recent two-flavor ($N_f=2$) lattice QCD calculation for pion-pion scattering in the scalar, isoscalar channel (the $σ$-meson). The lattice simulation was performed for two quark masses corresponding to a pion mass of 315 MeV and 227 MeV. The $σ$-meson parameters are extracted using various parametrizations of the scattering amplitude. The results obtained from a chiral unitary parametrization are extrapolated to the physical point and read $M_σ=( 440^{+10}_{-16}(50) - i\,240(20)(25))$ MeV, where the uncertainties in the parentheses denote the stochastic and systematic ones. The behavior of the $σ$-meson parameters with increasing pion mass is discussed as well.

Poster presented at the XIV International Workshop on Hadron Physics, Florianópolis, Brazil, March 2018