Light and Strange Vector Resonances from Lattice QCD at Physical Quark Masses

Area of Science:

• * Nuclear Physics and Quantum Chromodynamics
• * Hadron Spectroscopy and Scattering Theory

Background:

• * Understanding the strong force interactions between the lightest pseudoscalar mesons is crucial for nuclear physics.
• * Short-lived resonances like the rho(770) and K*(892) are key manifestations of these interactions.
• * Previous ab initio calculations at physical quark masses for these specific scattering channels were limited.

Purpose of the Study:

• * To perform the first ab initio calculation of scattering amplitudes for lightest pseudoscalar mesons interacting via the strong force in the vector channel.
• * To determine the defining parameters (mass and width) of the rho(770) and K*(892) resonances.
• * To provide precise postdictions of resonance properties using lattice quantum chromodynamics.

Main Methods:

• * Utilized lattice quantum chromodynamics (LQCD) to compute the finite-volume energy spectrum of two-hadron systems.
• * Employed the Lüscher formalism to derive scattering amplitudes from the calculated energy spectrum.
• * Incorporated a data-driven systematic error analysis by scanning fit ranges and models.

Main Results:

• * Calculated the mass and width for the rho(770) resonance: M_ρ=796(5)(50) MeV, Γ_ρ=192(10)(31) MeV.
• * Determined the mass and width for the K*(892) resonance: M_K*=893(2)(54) MeV, Γ_K*=51(2)(11) MeV.
• * Results obtained by analytically continuing multiple parametrizations into the complex energy plane.

Conclusions:

• * The study successfully performed the first ab initio calculation of vector channel scattering amplitudes for lightest pseudoscalar mesons at physical quark masses.
• * Precise values for the rho(770) and K*(892) resonance parameters were determined, validating theoretical models.
• * The methodology provides a robust framework for future investigations into hadron spectroscopy and strong force dynamics.