From Weinberg-Witten theorem, people say that the graviton (which has spin 2) can not be composite. But it seems that graviton can still be composite particle by combining spin-3/2 particles. Is there any reason why this is not possible?
The Weinberg-Witten theorem is used to deduce that the graviton is not composite using the fact that it has spin 2, not the other way around.
$\begingroup$ I believe OP is asking what the mechanism (analogous to W-W for spin 1/2 and 1) for preventing gravitons from being composed of spin 3/2 particles is $\endgroup$ Dec 3, 2020 at 4:36