We compute the bound state properties of three-dimensional scalar ϕ4 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.
G. Eichmann, A. Gómez, J. Horak, J. M. Pawlowski, J Wessely, N Wink, “Bound states from the spectral Bethe-Salpeter equation”, Oct. 25, 2023, arXiv:2310.16353 (2023).
Related to Project A02, B03, C01