[raxxorraxor]

There probably is a hard limit on how many elemental particles you can find in the first place. I don't know if there are further theories. Are there X or Y-Bosons? Lowfat quark anti-particles?

[gus_massa]

There are many enhancements of the Standard Model https://en.wikipedia.org/wiki/Physics_beyond_the_Standard_Mo... Some of them propose new particles, some of them make small changes to the particles we know.