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Nonperturbative study of generalized ladder graphs in a ϕ^2χtheory

Taco Nieuwenhuis·J. A. Tjon
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Abstract

The Feynman-Schwinger representation is used to construct scalar-scalar bound states for the set of all ladder and crossed-ladder graphs in a ϕ^2χtheory in (3+1) dimensions. The results are compared to those of the usual Bethe-Salpeter equation in the ladder approximation and of several quasi-potential equations. Particularly for large couplings, the ladder predictions are seen to underestimate the binding energy significantly as compared to the generalized ladder case, whereas the solutions of the quasi-potential equations provide a better correspondence. Results for the calculated bound state wave functions are also presented.

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Taco Nieuwenhuis, J. A. Tjon. 1996-06-21. Nonperturbative study of generalized ladder graphs in a ϕ^2χtheory. https://doi.org/10.1103/physrevlett.77.814

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