1997/03/12 by J. Bijtebier · 11 citations
Mathematics · Physics and Astronomy · #Bethe–Salpeter equation #Bound state #Combinatorics #Conjecture #Function (biology) #Limit (mathematics) #Mathematical analysis #Mathematical physics #Mathematics #Particle physics theoretical and experimental studies #Physics #Quantum Chromodynamics and Particle Interactions #Quantum many-body systems #Quantum mechanics #Spurious relationship #Wave function #hep-th #nucl-th
paper · pdf · doi:10.1016/s0375-9474(97)00462-4
published in Nuclear Physics A 623(3-4), 498-518 (Elsevier BV) · 11 pages Latex, 1 figure Postscript. Submitted to Journal of Physics G
arxiv created 1997/03/12 · openalex publication_date 1997/09/01 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We show that the 3D reductions of the Bethe-Salpeter equation have the same bound state spectrum as the original equation, with the possible exception of some solutions for which the corresponding 3D wave function vanishes. The abnormal solutions of the Bethe-Salpeter equation (corresponding to excitations in the relative time-energy degree of freedom), when they exist, are recovered in the 3D reductions via a complicated dependence of the final potential on the total energy. We know however that the one-body (or one high mass) limit of some 3D reductions of the exact Bethe-Salpeter equation leads to a compact 3D equation (by a mutual cancellation of the ladder and crossed graph contributions), which does not exhibit this kind of dependence on the total energy anymore. We conclude that the exact Bethe-Salpeter equation has no abnormal solution at this limit, or has only solutions for which our 3D wave function vanishes. This is in contrast with the results of the ladder approximation, where no such cancellation occurs. We draw the same conclusions for the static model, which we obtain by letting the mass of the lighter particle go also to infinity. These results support Wick's conjecture that the abnormal solutions are a spurious consequence of the ladder approximation.