We use lattice QCD and the L\"uscher method to study elastic pion-nucleon scattering in the isospin I=3/2 channel, which couples to the Δ(1232) resonance. Our Nf=2+1 flavor lattice setup features a pion mass of mπ≈250 MeV, such that the strong decay channel Δ→πN is close to the threshold. We present our method for constructing the required lattice correlation functions from single- and two-hadron interpolating fields and their projection to irreducible representations of the relevant symmetry group of the lattice. We show preliminary results for the energy spectra in selected moving frames and irreducible representations, and extract the scattering phase shifts. Using a Breit-Wigner fit, we also determine the resonance mass mΔ and the gΔ−πN coupling.
@article{arxiv.1812.01059,
title = {Towards the P-wave nucleon-pion scattering amplitude in the $\Delta (1232)$ channel},
author = {Srijit Paul and Giorgio Silvi and Constantia Alexandrou and Giannis Koutsou and Stefan Krieg and Luka Leskovec and Stefan Meinel and John Negele and Marcus Petschlies and Andrew Pochinsky and Gumaro Rendon and Sergey Syritsyn},
journal= {arXiv preprint arXiv:1812.01059},
year = {2019}
}
Comments
14 pages, 7 figures, Proceedings of the 36th Annual International Symposium on Lattice Field Theory (Lattice 2018), 22-28 July 2018, Michigan State University, East Lansing, Michigan USA