2024/06/03 by Liam Hockley, Hockley, Liam, Curtis D. Abell +5
Engineering · Physics and Astronomy · #Particle Accelerators and Free-Electron Lasers #Pulsars and Gravitational Waves Research #Quantum Chromodynamics and Particle Interactions
paper · pdf · doi:10.48550/arxiv.2406.00981
We present a coupled-channel analysis of the JP = 3/2+ Δ-baryon spectrum, based in the framework of Hamiltonian Effective Field Theory (HEFT). We construct a Hamiltonian which mixes quark model-like single-particle states and two-particle meson-baryon channels, and constrain this via experimentally measured πN → πN scattering observables. In the same vein as Lüscher's approach, we then connect this infinite-volume inspired Hamiltonian with finite-volume lattice QCD results. Drawing on lattice correlation-matrix eigenvectors identifying the 1s and 2s states in the finite-volume Δ(3/2+) spectrum, and utilising the HEFT eigenvectors describing the composition of the energy eigenstates, we resolve the structure of these states and their relation to the Δ(1600) resonance. We find the dominant contributions to this resonance come from strong rescattering in the πN and πΔ channels. This contrasts the long-held view of a dominant quark model-like core for the Δ(1600) . Further discussion of other contemporary lattice results for the Δ spectrum and πN scattering states is also presented.