Why the research of unstable collision particles not present in ordinary stable matter is important in high-energy physics? What is the point and merits of researching artificial made collision product unstable non natural occurring and not present in ordinary stable matter particles?
Like for example leptoquarks. Wikipedia says that they are not present in ordinary matter.
If they are not present in ordinary matter and not related with ordinary matter what use they can have in explaining natural occurring matter?
 A: The history of physics experimental research shows that the higher the energy of the particles used in interactions the more one learns how to build theoretical models that fit and are predictive of new data. The aim of particle research now is to find a mathematical theory that fits all known forces and is predictive of new situations.
The higher energy experiments and the finding  new particles that need high energy to be created, will choose between various present theories the one that predicts this particle. If the leptoquarks become well defined statistically, a particular GUT theory will be chosen.
Please note that the fact that we sit exchanging ideas presently over the internet, is very dependent on research in the middle of 20th century in elementary particles of the time. They kept extending the theories and also demanding the best possible computer technology and data gathering methods , that were later used widely in the industry.
A: Here is another reason for studying high-energy particle collisions, which produce unstable particles not found in ordinary matter.
There was a time immediately after the big bang when all the particles present had truly gigantic energies, and were experiencing constant collisions with all their neighbors at those high energies.
This meant that within that very early slice of time, unstable particles were all over the place and their collisions and interactions determined the later fate of the universe as it was expanding.
Then, as things were cooling off, the unstable particles decayed into ever-more-stable states, leaving only stable particles from which to eventually construct matter (in the form of hydrogen and helium).
To understand the earliest moments of the universe's history and thereby understand why our universe looks the way it does today, we must understand the dynamics of unstable particles that were present way back then. This is done by simulating the way back conditions using particle accelerators.
