Worldgraph Approach to Yang-Mills Amplitudes from N=2 Spinning Particle
By coupling the N=2 spinning particle to background vector fields, we construct Yang-Mills amplitudes for trees and one loop. The vertex operators are derived through coupling the BRST charge; therefore background gauge invariance is manifest, and the Yang-Mills ghosts are automatically included in loop calculations by worldline ghosts. Inspired by string calculations, we extend the usual worldline approach to incorporate more "generalized" 1D manifolds. This new approach should be useful for constructing higher-point and higher-loop amplitudes.