Bound states from the spectral Bethe-Salpeter equation
Gernot Eichmann, Andrés Gómez, Jan Horak, Jan M. Pawlowski, Jonas Wessely, Nicolas Wink
Abstract
We compute the bound state properties of three-dimensional scalar <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:msup><a:mi>ϕ</a:mi><a:mn>4</a:mn></a:msup></a:math> theory in the broken phase. To this end, we extend the recently developed technique of spectral Dyson-Schwinger equations to solve the Bethe-Salpeter equation and determine the bound state spectrum. We employ consistent truncations for the two-, three- and four-point functions of the theory that recover the scaling properties in the infinite coupling limit. Our result for the mass of the lowest-lying bound state in this limit agrees very well with lattice determinations. Published by the American Physical Society 2024