Aim: How can we explain the four fundamental forces and the standard model?

1. Aim: How can we explain the four fundamental forces and the standard model? Do Now: List all the subatomic particles that you can think of

3. Weakest Strongest Gravitational Weak nuclear Electromagnetic Strong nuclear Four Fundamental Forces

4. Gravitational • Responsible for shaping the large scale structure of the universe (galaxies, stars, etc.)

5. Weak Nuclear • Responsible for • Radioactive decay • Fusion of the sun • Conversion of neutrons into protons in the nuclei

6. Electromagnetic • Includes electrostatic and magnetic forces

7. Strong Nuclear • Holds the nucleus together by resisting the repulsion of protons. • Very short range.

9. The Standard Model • All matter is composed of Hadrons and Leptons

10. Leptons • Made up of charged and neutral matter • Cannot be broken down (as of now); it is a fundamental particle • Experience weak force interactions

11. Charged Leptons electron muon tau Neutral Leptons electron neutrino muon neutrino tau neutrino

13. Hadrons • Subatomic particles composed of quarks (the fundamental particles of the Standard Model) • Experience strong force interactions

15. Mesons • Unstable • Consist of one quark and one anti-quark

16. Baryons • Mass is equal to or greater than a proton • Consists of protons and neutrons (the most common), and other types of matter

17. Quarks • Smallest known unit of matter • Cannot be isolated • Exists as: • baryon (3 quarks) or • meson (quark and anti-quark)

18. Fundamental Rule of Standard Model: For every particle, there exists an anti-particle

19. Quark Types

20. Antiquarks • Same mass, opposite charge • Represented with a line on top • Represents an anti-up quark • Charge is -

21. Protons and Neutrons • Are made of up and down quarks • Proton: charge is +1 • up, up, down (uud) • (+2/3) + (+2/3) + (-1/3) = +1 • Neutron: charge is 0 • up, down, down (udd) • (+2/3) + (-1/3) + (-1/3) = 0