literature

The ρ-resonance from Nf = 2 lattice QCD including the physical pion mass

Jun 24, 2020
7 pages
Published in:
  • Phys.Lett.B 819 (2021) 136449
  • Published: Jun 16, 2021
    and
  • Published: Aug 10, 2021
e-Print:
Experiments:

Citations per year

20202021202220232024101495
Abstract: (Elsevier B.V.)
We present a lattice computation of ππ–scattering in the I=1 channel with Nf=2 dynamical quark flavours obtained with ensembles bracketing the physical value of the pion mass. Employing a global fit to data at three values of the pion mass, we determine the universal parameters of the ρ-resonance. We carefully investigate systematic uncertainties by determining energy eigenvalues using different methods and by comparing inverse amplitude method and Breit-Wigner type parametrizations. Overall, exploring the complex energy plane we find mass Mρ=786(22)MeV and width Γρ=180(6)MeV, including statistical and systematic uncertainties. In contrast to previous Nf=2 extrapolations from higher than physical pion mass results, our mass value is in good agreement with experiment, while the width is too high.
Note:
  • pi: mass
  • quark: flavor
  • lattice field theory
  • parametrization
  • Breit-Wigner
  • statistical
  • lattice