After the Higgs Boson, perhaps the biggest discovery of the Large Hadron Collider (LHC) at CERN is that it hasn't discovered any other major predicted particles. This has called into question several long-established theoretical conjectures, such as Super Symmetry. Essentially LHC has been systematically erasing 30 years of theorists work off the chalkboard.
The remaining blank slate is a bit alarming. Where is the explanation for dark energy, or dark matter? Why is there a matter-antimatter asymmetry? It seems we are no closer to the answer to these and other questions than we were decades ago. Career's worth of work has been disproven in the last 5 years. It's hard to overstate the carnage LHC has produced in the particle physics world, by simply not finding stuff.
It goes to show that in Physics, sometimes no result is interesting. The search for particles continues on. Check out this article to see what the LHC is up to now:
https://atlas.cern/updates/physics-briefing/searching-forces-beyond-standard-model
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