Abstract

Amongst the bound states produced by the strong interaction, radially excited meson and nucleon states offer an important phenomenological window into the long-range behavior of the coupling constant in Quantum Chromodynamics. We here report on some technical details related to the computation of the bound state's eigenvalue spectrum in the framework of Bethe-Salpeter and Faddeev equations.

Highlights

  • Amongst the bound states produced by the strong interaction, radially excited meson and nucleon states offer an important phenomenological window into the longrange behavior of the coupling constant in Quantum Chromodynamics

  • A great deal of research activity in hadron physics is concerned with hadron structure and revolves around two fundamental questions: what constituents are the hadrons made of and how does Quantum Chromodynamics (QCD), the strong interaction component of the Standard Model, produce them? These are simple questions which, may not entail simple answers

  • To understand the measurable content of QCD, spectroscopy is a valuable and time-honored tool — suffice it to mention the inestimable progress made in the computation of atomic or molecular spectra and subsequent comparison with experiments that lead to a deeper understanding of Quantum Electrodynamics

Read more

Summary

Introduction: excited states as an eigenvalue problem

A great deal of research activity in hadron physics is concerned with hadron structure and revolves around two fundamental questions: what constituents are the hadrons made of and how does Quantum Chromodynamics (QCD), the strong interaction component of the Standard Model, produce them? These are simple questions which, may not entail simple answers. The Bethe-Salpeter equation’s Poincaré-invariant solutions can be cast in the form, Γ0− (p, P) = γ5 i IDE0− (p, P) + P/ F0− (p, P) + /p(p · P) G0− (p, P) + σμν pμPν H0− (p, P) , (3) Note that this Euclidean-metric basis, Aα(p, P) = γ5 i ID, P/ , /p(p · P), σμν pμPν , is nonorthogonal with respect to the Dirac trace. This is the most basic method of computing the largest eigenvalue λ0(P2) and its associated eigenvector to any required accuracy and is referred to as power or von Mises iteration The trajectory of this eigenvalue function for a range of P2 values yields the ground-state meson mass, that is one finds λ0(P2) = 1 when P2 = −m20

Gram-Schmidt orthogonalization
Krylov subspace and Arnoldi iteration
A note on orthogonality
Examples in hadron physics

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.