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

Matthias Fischer; Bartosz Kostrzewa; Maxim Mai; Marcus Petschlies; Ferenc Pittler; Martin Ueding; Carsten Urbach; Markus Werner

Physics Letters B (Aug 2021)

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

Matthias Fischer,
Bartosz Kostrzewa,
Maxim Mai,
Marcus Petschlies,
Ferenc Pittler,
Martin Ueding,
Carsten Urbach,
Markus Werner

Affiliations

Matthias Fischer: Helmholtz Institut für Strahlen- und Kernphysik, University of Bonn, Nussallee 14-16, 53115 Bonn, Germany; Bethe Center for Theoretical Physics, University of Bonn, Nussallee 12, 53115 Bonn, Germany
Bartosz Kostrzewa: High Performance Computing & Analytics Lab, University of Bonn, Friedrich-Hirzebruch-Allee 8, 53115 Bonn, Germany
Maxim Mai: The George Washington University, Washington, DC 20052, USA
Marcus Petschlies: Helmholtz Institut für Strahlen- und Kernphysik, University of Bonn, Nussallee 14-16, 53115 Bonn, Germany; Bethe Center for Theoretical Physics, University of Bonn, Nussallee 12, 53115 Bonn, Germany
Ferenc Pittler: Computation-Based Science and Technology Research Center, The Cyprus Institute, 20 Kavafi Str., Nicosia 2121, Cyprus
Martin Ueding: Helmholtz Institut für Strahlen- und Kernphysik, University of Bonn, Nussallee 14-16, 53115 Bonn, Germany; Bethe Center for Theoretical Physics, University of Bonn, Nussallee 12, 53115 Bonn, Germany
Carsten Urbach: Helmholtz Institut für Strahlen- und Kernphysik, University of Bonn, Nussallee 14-16, 53115 Bonn, Germany; Bethe Center for Theoretical Physics, University of Bonn, Nussallee 12, 53115 Bonn, Germany; Corresponding author.
Markus Werner: Helmholtz Institut für Strahlen- und Kernphysik, University of Bonn, Nussallee 14-16, 53115 Bonn, Germany; Bethe Center for Theoretical Physics, University of Bonn, Nussallee 12, 53115 Bonn, Germany

Journal volume & issue: Vol. 819
p. 136449

Abstract

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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.

Published in Physics Letters B

ISSN: 0370-2693 (Print); 1873-2445 (Online)
Publisher: Elsevier
Country of publisher: Netherlands
LCC subjects: Science: Physics
Website: http://www.journals.elsevier.com/physics-letters-b/

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