Particle Demolition Derby
Subatomic particles are detected using colliders. A focused beam of specific particles, such as electrons or protons, is accelerated via electromagnetic jostle, then aimed to collide into an opposing beam. The heavier the particle, the more energy it takes to accelerate a beam. Then there is the need for speed. The faster the accelerator, the more spectacular the results in generating bits for boffins.
The latest generation of collider is The Large Hadron Collider (LHC), located near Geneva Switzerland. The LHC was built to hunt the Higgs boson by smacking protons, at a cost of €7.5 billion (euros) ($9 billion US). Like all human endeavors of significant scale, getting the Collider up and running collided with serious glitches and cost overruns.
Particle collisions create detectable tracks of decay. A hammered hadron decays into its constituent quarks and other lower-energy elementals.
Higher-generation particles, created by high-energy collisions, have greater mass and less stability. They decay into lower-generation particles by means of weak interactions.
Fermion decay can be rather directly observed, as these are chunks of matter. Bashed bosons are more mysterious. Their presence must be inferred from what they decay into.
The W boson may decay in many ways, which it does in less than 1 billion-trillionth of a second. If it dissolves into a puddle of neutrinos, it cannot be detected. If instead a W collapses to an electron or muon, it may be measured.
Computer simulations are run based on the equations that characterize a model; typically, the Standard Model. Transformations and decays at different energy levels are predicted.
Repeatedly matching telltale tracks from collisions with predictions builds confidence that a model is on track. Uncertainty propagates in each analysis. Many repetitive runs with similar results are necessary for validation.
