We study hadrons through solving the coupled system of the gap equation for the quark propagator and the bound-state equation for the wavefunction. The gap equation and the bound-state equation are in fact members of infinitely coupled Dyson–Schwinger equations of QCD's Green functions. To make it solvable, the system must be truncated. The simplest rainbow-ladder truncation is widely used and very useful. But it also shows drawbacks in many aspects. To improve the simplest truncation, we analyze symmetries of the fundamental theory and solve the corresponding Ward–Green–Takahashi identities. Then, the crucial elements of the gap equation and the bount-state equation can be constructed, accordingly. The new truncation is capable of describing spectrum of light hadrons including ground and low-lying radially excited states, and potentially applicable for studies of hadron structures.
Argonne Physics Division Seminar Schedule