Question: if the Graviton were to be discovered how would it change the standard model of physics?

Monique Henson answered on 16 Nov 2015:

Hmm, good question. I’m not sure we know yet. I think the current theories that include the Graviton are all extensions to the Standard Model of particle physics as we know it, so any discovery would cause a significant change to that. As to what would change, I imagine it would probably depend on what the properties of the discovered graviton were.

Any attempt to include gravity in the Standard Model of particle physics would require a quantum theory of gravity. At the moment, our ideas about gravity are limited to large scales (bigger than atoms) and our theories about quantum physics are limited to small scales. To combine gravity into the standard model, we need to come up with a quantum theory of gravity.

I say all this as an astronomer – so I’m not all that knowledgeable on the topic! There’s some information about the graviton from someone who knows quite a bit more than me here.