Emergence of the π(1300) Resonance from Lattice QCD

Area of Science:

• * Quantum Chromodynamics (QCD)
• * Hadron Spectroscopy

Background:

• * The pion's mass is significantly lighter than the nucleon and its excited state, the π(1300).
• * This mass difference is crucial for understanding quark confinement and hadron structure.

Purpose of the Study:

• * To perform the first lattice QCD calculation of the π(1300) resonance parameters.
• * To investigate the structure of the lightest hadrons and quark confinement.

Main Methods:

• * Utilized advanced lattice QCD techniques, including three-hadron operators.
• * Mapped finite-volume spectra to infinite-volume amplitudes and analytically continued to complex energies.
• * Employed chiral perturbation theory constraints and model averaging for extrapolation to the physical point.

Main Results:

• * Successfully identified a clear signal of the π(1300) resonance in heavy pion mass ensembles.
• * Extrapolated results to the physical point using specific assumptions and constraints.
• * Extracted a pole position for the π(1300) of M_{π(1300)}=(1169±46)-i(62_{-62}^{+168})MeV.

Conclusions:

• * The calculated resonance parameters support existing phenomenological values.
• * This study offers crucial data for understanding the nature of the π(1300) and fundamental QCD principles.