Hypothetically, gravitons have no charge, so they are their own antiparticles. I believe that is the thing: when gravitons are interacting, photons can't exist, for they are the uninteraction of gravitons. So when photons crash with a mass, if thia mass is a loosing electrons matter (metal), the electron will be produced, or better said accelerated by the enrgy taken from the photon by the atom. Whiles if the matter is electrong aining, the energy wil be retaine din the nucleus. What happens is that the photon is repelled with colour. I believe that because in the non-metals there are always more neutrons than protons or equal, then the number of up quarks is higher than te one of down quarks, that impplies that although the charge is still overall 0, the charge of the force that puts the quarks together is positive. Is this the weak force?
Basically, I mean that the electron is a product of graviton interaction and the photon a product of graviton noninteraction.