Resonance Parameters of the rho-Meson from Lattice QCD

TL;DR

This paper presents a lattice QCD study of the rho-meson resonance parameters by calculating pion-pion scattering phases at various pion masses, enabling extraction of the rho-meson mass and decay width.

Contribution

It introduces a non-perturbative lattice approach to determine rho-meson resonance parameters across different quark masses using finite-size methods.

Findings

Successful extraction of rho-meson mass and decay width.

Good agreement of scattering phase with effective range formula.

Analysis of quark mass dependence of resonance parameters.

Abstract

We perform a non-perturbative lattice calculation of the P-wave pion-pion scattering phase in the rho-meson decay channel using two flavors of maximally twisted mass fermions at pion masses ranging from 480 MeV to 290 MeV. Making use of finite-size methods, we evaluate the pion-pion scattering phase in the center-of-mass frame and two moving frames. Applying an effective range formula, we find a good description of our results for the scattering phase as a function of the energy covering the resonance region. This allows us to extract the rho-meson mass and decay width and to study their quark mass dependence.