ππ P-wave resonant scattering from lattice QCD
Computation-based Science and Technology Research Center, The Cyprus Institute, 20 Kavafi Str., Nicosia, 2121, Cyprus
2 Department of Physics, University of Cyprus, POB 20537, 1678 Nicosia, Cyprus
Department of Physics, University of Arizona, Tucson, AZ 85721, USA
4 RIKEN BNL Research Center, Brookhaven National Laboratory, Upton, NY 11973, USA
5 Center for Theoretical Physics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
6 Department of Mathematics and Natural Sciences, University of Wuppertal, D-42119 Wuppertal, Germany
7 Helmholtz-Institut für Strahlen-und Kernphysik, University of Bonn, D-53115 Bonn, Germany
8 Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY 11794, USA
* Speaker, e-mail: email@example.com
Published online: 26 March 2018
We present a high-statistics analysis of the ρ resonance in ππ scattering, using 2 + 1 flavors of clover fermions at a pion mass of approximately 320 MeV and a lattice size of approximately 3:6 fm. The computation of the two-point functions are carried out using combinations of forward, sequential, and stochastic propagators. For the extraction of the ρ-resonance parameters, we compare different fit methods and demonstrate their consistency. For the ππ scattering phase shift, we consider different Breit-Wigner parametrizations and also investigate possible nonresonant contributions. We find that the minimal Breit-Wigner model is suffcient to describe our data, and obtain amρ = 0:4609(16)stat(14)sys and gρππ = 5:69(13)stat(16)sys. In our comparison with other lattice QCD results, we consider the dimensionless ratios amρ/amN and amπ/amN to avoid scale setting ambiguities.
© The Authors, published by EDP Sciences, 2018
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