Is it true that for any vertex that occurs in the Standard Model, that same vertex with two of the particles replaced with their superpartners will be allowed by supersymmetry?

Just to clarify (since the first question was a bit brief) I know that this works in many cases, but wasn’t sure if it’s a general rule.

Is this what you are refering to?

** Basic Supersymmetry **

Regret I am of little if any help otherwise.

Hmph. To me, a “basic” supersymmetry question would be: what the hell is it?

Supersymmetry isn’t my area of expertise, but I do believe that this is the case. However, I have a feeling that this would be the case only if the background solution you’re working around is itself supersymmetric; in other words, this wouldn’t be the case in the real world.

I’ll drag out my copies of Wess & Bagger and Bailin & Love when I get in to work tomorrow if nobody’s posted a more definitive answer by then.

Yeah, I guess what I mean is it’s (I think) a basic question for people who’ve studied supersymmetry.

In answer to your *more* basic question, Supersymmetry is a theory that says that for each of the fundamental particles of the “Standard Model” of particle physics there is an as-yet-undetected particle that corresponds to it (its “superpartner”), which differs from the original particle by half a unit of spin.

As far as the *reasons* for believing these particles exist, I’m sure there are other people on this board who are more qualified to tell you than I am.

Off the top of my head - running through the allowed cases I can remember in the minimal SSM - I agree with **MikeS**: graphically, any such vertex produced by such a substitution will be a possible vertex.

There is presumably a two-line proof of the assertion, but I don’t quite see it.

MikeS–I looked in Bailin & Love, and it wasn’t much help.

I can’t wait to find out the answer to this–I’ve been studying supersymmetry for two quarters now and it’s embarassing that I don’t know the answers to simple questions like this one.

I asked Michael Dine, my advisor, about this today and he says that for every standard model vertex there is an equivalent supersymmetric vertex, with any two of the standard model particles replaced by their superpartners, just like the OP said.

For example, he claims that the interaction (electron + positron -> photon) can be replaced by (selectron + antiselectron -> photon), and a similar replacement can be made for all vertices.