Axial-Vector D_{1} Hadrons in D^{*}π Scattering from QCD.

Area of Science:

• * Quantum Chromodynamics (QCD) and hadron spectroscopy.
• * Theoretical particle physics.
• * Nuclear and subatomic physics.

Background:

• * Understanding the properties of heavy-light mesons is crucial for testing the Standard Model.
• * Lattice QCD provides a non-perturbative approach to study these properties.
• * Previous studies have explored D-meson properties, but detailed scattering amplitude analysis is ongoing.

Purpose of the Study:

• * To determine low-lying J^P=1^+ axial-vector D1 states and a J^P=2^+ tensor D2*.
• * To analyze I=1/2 D*π scattering amplitudes using lattice QCD.
• * To investigate the nature of resonances and bound states in heavy-light meson systems.

Main Methods:

• * Computation of finite-volume spectra at a specific light-quark mass (m_π ≈ 391 MeV).
• * Application of Lüscher's quantization condition to constrain coupled D*π and Dπ amplitudes.
• * Analysis of scattering amplitudes for poles to identify resonances and bound states.

Main Results:

• * Identification of two low-lying J^P=1^+ axial-vector D1 states and one J^P=2^+ tensor D2*.
• * Discovery of a near-threshold bound state in D*π (³S₁) and a D1 resonance in D*π (³D₁).
• * A single resonance found for the J^P=2^+ channel coupled to Dπ and D*π.

Conclusions:

• * The lightest D1 state exhibits a low mass and large coupling, suggesting it evolves into a broad resonance as quark mass decreases.
• * The results offer valuable comparisons with previous calculations of the scalar D0*.
• * This study advances the understanding of heavy-light meson spectroscopy and dynamics from first principles.