Document Type

Article

Publication Date

2021

DOI

10.1103/PhysRevD.103.094508

Publication Title

Physical Review D

Volume

103

Issue

9

Pages

1-17

Abstract

We determine the Δ(1232) resonance parameters using lattice QCD and the Lüscher method. The resonance occurs in elastic pion-nucleon scattering with JP = 3/2+ in the isospin I=3/2, P-wave channel. Our calculation is performed with Nf = 2+1 flavors of clover fermions on a lattice with L ≈ 2.8 fm. The pion and nucleon masses are mπ = 255.4 (1.6) MeV and mN = 1073(5) MeV, respectively, and the strong decay channel Δ → πN is found to be above the threshold. To thoroughly map out the energy dependence of the nucleon-pion scattering amplitude, we compute the spectra in all relevant irreducible representations of the lattice symmetry groups for total momenta up to →P = 2πL(1,1,1), including irreps that mix S and P waves. We perform global fits of the amplitude parameters to up to 21 energy levels, using a Breit-Wigner model for the P-wave phase shift and the effective-range expansion for the S-wave phase shift. From the location of the pole in the P-wave scattering amplitude, we obtain the resonance mass mΔ = 1378(7)(9) MeV and the coupling gΔ-πN = 23.8(2.7)(0.9).

Comments

Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.

Publisher's version available at: https://doi.org/10.1103/PhysRevD.103.094508

Original Publication Citation

Silvi, G., Paul, S., Alexandrou, C., Krieg, S., Leskovec, L., Meinel, S., . . . Todaro, A. (2021). P-wave nucleon-pion scattering amplitude in the Δ(1232) channel from lattice QCD. Physical Review D, 103(9), Article 094508, 1-17. https://doi.org/10.1103/PhysRevD.103.094508.

ORCID

0000-0002-8926-527X (Leskovec)

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