system
Given the following post, respond as if you're commenting on Reddit:
human
Why has no theory on baryogenesis considered that particles in the early universe could've collided in more than pairs, explaining why there is more matter than antimatter in the Universe?

In the early Universe there should've been an equal amount of matter and antimatter particles, as matter and antimatter particles always form in pairs as we've learned from experiments at the Large Hadron Collider and elsewhere; yet there appears to be more matter than antimatter in the universe.

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No one, it seems, has been able to figure out why this imbalance, dubbed the baryon asymmetry problem (or the matter-antimatter asymmetry problem) occurred, and many proposed theories, from hypothetical X and Y bosons that can violate the symmetry and lead to baryogenesis (the creation of matter independent of antimatter), to entire areas of the universe dominated by antimatter that are too far away to see, explaining away the missing antimatter; all of which so far have fallen flat in the search for experimental evidence.

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Yet all those theories, to my understanding, seem to take a strange assumption: that particles can only collide in pairs.

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What if in the early universe some of the matter and antimatter particles collided in groups of three?  In my amateur research into the topic, I've read up that particle and antiparticle collisions are 100% efficient, and produce their entire mass worth of energy when equal amounts of particle are collided.  Under a collision of three particles, however, there seems to be little research I could find, most likely because such collisions are so rare in nature and experimentation (which as a side note could explain why so few matter particles, about one in a billion, survived).

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Extrapolating what I know of how matter collisions work (please correct me if I'm wrong, I don't do this for a living), if a collision of 3 particles, let's say a certain particle *P* and two identical antiparticles *Q* such that the two *Q* particles' properties "add" up to be equivalent to the properties of the antimatter counterpart of *P*, then shouldn't all three particles get converted into energy just as if the particle-antiparticle pair of *P* would've collided instead?  The example may be a ways off from how it works, I'm no physicist, but I hope the gist of it comes through.

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If such a scenario that I've described above is impossible, then is there another scenario such that an odd number of particles and its associated antiparticles can collide and completely be converted into energy with 100% efficiency?  If so, then could such three-particle collision be common enough to result in the slight difference in the ratio of matter to antimatter from baryogenesis?
gpt
If you have a process as you describe, you also have a process of the 3 antiparticle partners of those particles undergoing a process that destroys an antiP and two Qs annihilating to create energy. That process would provide the opposite contribution you’re imagining, unless the process itself is symmetry violating.  But there isnt enough symmetry violating strength in standard model processes like those you imagine.