Elastic nucleon-pion scattering at $m_{\pi} = 200~{\rm MeV}$ from lattice QCD

Autor: Bulava, John, Hanlon, Andrew D., Hörz, Ben, Morningstar, Colin, Nicholson, Amy, Romero-López, Fernando, Skinner, Sarah, Vranas, Pavlos, Walker-Loud, André
Rok vydání: 2022
Předmět:
Druh dokumentu: Working Paper
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 $N_{\rm f} = 2+1$ dynamical quark flavors and $m_{\pi} = 200~{\rm MeV}$. 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 $\Delta(1232)$ 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 $I = 1/2$ is somewhat less precise. Systematic errors due to excited states and the influence of higher partial waves are controlled, providing a pathway for future computations down to the physical light quark masses with multiple lattice spacings and physical volumes.
Comment: 33 pages, 16 figures; version accepted for publication
Databáze: arXiv