Lesson Plan

Describe quarks and explain their relationship to hadrons and to the other fundamental particles

Distinguish hadrons from leptons by the forces they feel and by their internal structure

Distinguish matter from antimatter and explain pair production and annihilation

Describe the Standard Model — its particle types, families, and the forces it organizes

Define the Higgs boson and the Higgs field and explain their importance to particle physics

23.2

"According to the Standard Model, there are three types of fundamental particles: leptons, quarks, and carrier particles." "At first, physicists expected that, with sufficient energy, we should be able to free quarks and observe them directly. However, this has not proved possible, as the current understanding is that the force holding quarks together is incredibly great and, much like a spring, increases in magnitude as the quarks are separated." "The fractional charge of quarks, which are ±(2/3)qₑ and ±(1/3)qₑ, are the only structures found in nature with a nonintegral number of charge q." "Hadrons are particles that feel the strong nuclear force, whereas leptons are particles that do not." "Annihilation is the process of destruction that occurs when a particle and its antiparticle interact. As soon as two particles (like a positron and an electron) coincide, they convert their masses to energy through the equation E = mc²."