QCD Predictions for Physical Multimeson Scattering Amplitudes.

Area of Science:

• Quantum Chromodynamics (QCD)
• Particle Physics
• Nuclear Physics

Background:

• Understanding multi-particle interactions is crucial in quantum chromodynamics.
• Previous calculations often relied on unphysical quark masses or simplified models.

Purpose of the Study:

• To determine three-particle scattering amplitudes for the first time using physical quark masses.
• To calculate two- and three-meson systems, specifically involving pions (π⁺) and kaons (K⁺).
• To provide accurate determinations of two-meson amplitudes at the physical point.

Main Methods:

• Utilized lattice QCD calculations with a lattice spacing of a=0.063 fm.
• Employed the stochastic Laplacian-Heaviside method to obtain dense lattice spectra.
• Applied the relativistic finite-volume formalism for scattering amplitude analysis.

Main Results:

• First determination of three-particle scattering amplitudes with physical quark masses.
• Accurate results for maximal-isospin two-meson amplitudes (π⁺K⁺ and 2K⁺) at the physical point.
• Results show good agreement when compared to chiral perturbation theory and experimental data fits.

Conclusions:

• Lattice QCD calculations are capable of determining multi-particle scattering amplitudes at physical quark masses.
• The study provides valuable benchmarks for theoretical models and experimental interpretations.
• This work advances the understanding of meson interactions in the isospin-symmetric limit.