1- Brane Sources for the Lightcone Worldsheet: Q-branion - {bar Q}-branion Scattering to One Loop

This paper extends the study, initiated by Rozowsky and Thorn [1], of gauge fields in interaction with Dirac fields living on separated parallel 1-branes. In a lightcone description, replacing static point sources by 1-brane sources allows p^+ conservation to be maintained in their presence, which simplifies the lightcone quantization procedure. Here we calculate on-shell branion scattering amplitudes through 1 loop in lightcone gauge, and thereby resolve a puzzling ambiguity encountered in the off-shell calculations of [1]. We confirm that infrared divergences cancel in properly defined scattering probabilities. This work lays the groundwork for the incorporation of 1-brane sources in the lightcone worldsheet formalism.