Hadronic bound states in SU(2) from Dyson-Schwinger equations.

Milan Vujinovic,Richard Williams

doi:10.1140/epjc/s10052-015-3324-x

Milan Vujinovic, Richard Williams

Open Access

https://doi.org/10.1140/epjc/s10052-015-3324-x

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Abstract

By using the Dyson–Schwinger/Bethe–Salpeter formalism in Euclidean spacetime, we calculate the ground state spectrum of Jle 1 hadrons in an SU(2) gauge theory with two fundamental fermions. We show that the rainbow-ladder truncation, commonly employed in QCD studies, is unsuitable for a description of an SU(2) theory. This we remedy by truncating at the level of the quark–gluon vertex Dyson–Schwinger equation in a diagrammatic expansion. Results obtained within this novel approach show good agreement with lattice studies. These findings emphasize the need to use techniques more sophisticated than rainbow-ladder when investigating generic strongly interacting gauge theories.

Highlights

Quantum chromodynamics (QCD) is a strongly interacting gauge theory whose study has proven to be one of the most formidable challenges of modern theoretical physics
We wish to concentrate on the situation with two fundamentally charged Dirac fermions [1,8,10,11]. Such a theory may be interesting in the context of a unified description of cold asymmetric Dark Matter (DM) and dynamical electroweak (EW) symmetry breaking [12,13,14], wherein the ground state hadronic spectrum at T = 0, μ = 0 is of great importance
We can test the sensitivity of the truncation by varying the solution of the quark–gluon vertex within the constraints imposed by chiral symmetry breaking and the axial-vector Ward–Takahashi identity (axWTI)

Summary

Introduction

Quantum chromodynamics (QCD) is a strongly interacting gauge theory whose study has proven to be one of the most formidable challenges of modern theoretical physics. We wish to concentrate on the situation with two fundamentally charged Dirac fermions [1,8,10,11] Such a theory may be interesting in the context of a unified description of cold asymmetric Dark Matter (DM) and dynamical electroweak (EW) symmetry breaking [12,13,14], wherein the ground state hadronic spectrum at T = 0, μ = 0 is of great importance. It is exactly this hadronic spectrum that will be the central focus of our study

Results

Discussion

Conclusion