Collision of atomic nuclei at an appreciable portion of light speed is the typical source of origin. The high velocity supplies sufficient energy to form the more exotic particles.
How Kaons originate from an exotic condensate? of hydrogen poses new questions. A Kaon’s mass turned to energy is better than half that of a Proton. The source of the energy of formation, the route of a process for particle generation under cold matter conditions remains.
You call it “ cold matter conditions” but it might be sumthin more akin to RELATIVE cold conditions.
Ferinstance, one of the researchers who hit the highest COPs, used h1 gas rather than h2 gas. H1 gas wants to form into h2 gas before it does anything else, In an ENDOthermic reaction.
Generating RELATIVE cold conditions.