I have been watching Prof Susskind's lectures on String Theory. I am trying to understand a little more about D branes. I am trying to reproduce a basic quark-gluon interaction. I have the following:http://www.firstcoasttutors.com/images/pf.jpg [Broken] I think this might describe the right hand side of the Feynman diagram but am not sure. If so, is the incoming side just more or less the green and red arrows inverted. Am I even remotely close here.?