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The LHC Battle for Naturalness on the Top Charm Front

Final Report Summary - TOPCHARM (The LHC Battle for Naturalness on the Top Charm Front)

The field of particle physics is currently at an important historical junction. The Standard Model (SM) of fundamental particles and interactions seems to correctly describe nature at the microscopic level. It, however, cannot account for neutrino masses, the baryon asymmetry of the universe the existence of dark matter. In addition, the SM suffers from three kind of hierarchies issues: the first is related to the fine tuning of the Higgs mass; the second is related to the observed hierarchies in the elementary fermion masses, or basic matter fields, the third to the strong CP problem. On the other hand of the successful discovery of the Higgs at the LHC we are now facing with a complete incomplete theory, in the sense that it is mathematically fully consistent, however it does not have any basic missing ingredients to hint for what would be the ideal way to experimentally search for ways to address the above shortcoming of this closed-form structure, denoted as the standard model.
For several decades the leading strategy to look for new physics followed from the paradigm that these problem are unrelated and the Higgs fine tuning is solved via an independent symmetry principle. This principle predicts that the SM fields are part of a larger multiplet, invariant under some fundamental symmetry. We are generically expected these to be found at the Large Hadron Collider (LHC) era. However, despite an intense theoretical and enormous experimental effort done by the LHC experiments at the energy frontier, so far none of these partners was found.
The research done by us aimed towards tackling the very basic assumptions that lead the particle physics community to the above deadlock.
We have shown that flavor and naturalness are shown to possibly not being an independent concept, and there are concrete ways to test models where Higgs and flavor physics are connected to each others. We have further demonstrated that there are ways to study flavor physics using the Higgs, including new manners for which we can test the origin of light fermion masses at colliders.
We have provided set of preliminary studies showing that there are new type of new physics scenario, that goes beyond the conventional paradigms of new physics, that can be tested at collider, accelerators, at the luminosity frontier and even beyond, where one can see how flavor physics and the solution to the hierarchy problem are bundled together.