Elastic nucleon-pion scattering at mπ = 200 MeV from lattice QCD

Autor: John Bulava, Andrew D. Hanlon, Ben Hörz, Colin Morningstar, Amy Nicholson, Fernando Romero-López, Sarah Skinner, Pavlos Vranas, André Walker-Loud
Jazyk: angličtina
Rok vydání: 2023
Předmět:
Zdroj: Nuclear Physics B, Vol 987, Iss , Pp 116105- (2023)
Druh dokumentu: article
ISSN: 0550-3213
DOI: 10.1016/j.nuclphysb.2023.116105
Popis: Elastic nucleon-pion scattering amplitudes are computed using lattice QCD on a single ensemble of gauge field configurations with Nf=2+1 dynamical quark flavors and mπ=200MeV. The s-wave scattering lengths with both total isospins I=1/2 and I=3/2 are inferred from the finite-volume spectrum below the inelastic threshold together with the I=3/2 p-wave containing the Δ(1232) resonance. The amplitudes are well-described by the effective range expansion with parameters constrained by fits to the finite-volume energy levels, enabling a determination of the I=3/2 scattering length with statistical errors below 5%, while the I=1/2 scattering length is somewhat less precisely evaluated. Systematic errors due to excited states and the influence of higher partial waves are controlled, providing a step toward future computations down to physical light quark masses with multiple lattice spacings and volumes.
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