Robert Mann - An Introduction to Particle Physics and the Standard Model · Problem 15.1
Testing the Quark Model — Robert Mann
Physics — Particle Physics · quark-quantum-numbers-existence
Problem
Do the following exist? Why or why not? ((a)) an antibaryon with charge ((b)) a positive meson with strangeness ((c)) a spin-0 baryonIntuitive explanation
Particle existence hinges on conservation laws and the fundamental building blocks available. Baryons are made of three quarks (or three antiquarks for antibaryons), mesons from quark–antiquark pairs, and each quark carries specific quantum numbers like charge and strangeness. The key is to check whether the required quantum numbers can actually be constructed from these ingredients while respecting the rules—for instance, antibaryons flip the signs of their constituent quarks' charges and strangeness, and spin combines according to quantum mechanics. Work through each case by asking: can I build this from the available quarks, and do the quantum numbers add up correctly?
Intuitive explanation
Particle existence hinges on conservation laws and the fundamental building blocks available. Baryons are made of three quarks (or three antiquarks for antibaryons), mesons from quark–antiquark pairs, and each quark carries specific quantum numbers like charge and strangeness. The key is to check whether the required quantum numbers can actually be constructed from these ingredients while respecting the rules—for instance, antibaryons flip the signs of their constituent quarks' charges and strangeness, and spin combines according to quantum mechanics. Work through each case by asking: can I build this from the available quarks, and do the quantum numbers add up correctly?