INTRODUCTION By the mid-1960's, physicists realized that their previous understanding, where all matter is composed of the fundamental protons, neutrons, and electron, was insufficient to explain the myriad new particles being discovered. Gell-Mann's and Zweig's quark theory solved these problems. Over the last thirty years, the theory that is now called the Standard Model of particles and interactions has gradually grown and gained increasing acceptance with new evidence from new particle accelerators. In this PhysicsQuest you will investigate the Standard Model.
PROCESS AND RESOURCES - Visit the links to The Particle Adventure provided for each section and answer the questions. PART I. 1. This section discusses what is meant by fundamental in terms of the constituents of matter. Briefly describe the key ideas given in this section. 2. Discuss the concept of antimatter. 3. What are the three main components of the Standard Model? PART II. 4. How many types of quarks are there and what kind of charge do they have? 5. Quarks exist in groups called hadrons. Describe the two types of hadrons and what kinds of particles do they form. 6. Explain what is meant by the fact that only a very small part of the mass of a hadron is due to the quarks in it. 7. How many leptons are there and which are their characteristics? 8. Explain why the muon and the tau, are not found in ordinary matter at all. 9. What are the characteristics of neutrinos and what is their importance related to the expansion of the universe? 10. Draw a chart with the three generations of matter clearly labeled.
PART III. 11. Name the four fundamental interactions between particles. 12. What is the difference between a force and an interaction? 13. Explain the electromagnetic force and who is the carrier of this force. 14. Describe the strong force. 15. What are the gluons? 16. Explain what the color charge is and how it is assigned to particles, antiparticles and gluons. 17. Describe the weak interactions.
PART III. 18. Explain how physicists apply the concepts of momentum and wavelength to study particles. PART IV. 19. How does an accelerator work? 20. How do you obtain electrons, protons and antiparticles? 21. What are the types of collisions that can be produced in accelerators? 22. What is the difference between a linac and a synchrotrons? 23. What are the main advantages of a circular accelerator over a linear accelerator? 24. Explain what is meant by an event. 25. To analyze the collisions of particles in an event scientists use detectors. Explain why are detectors shaped in different forms. 26. Modern detectors consist of different components. Explain what is the purpose of having various components.
PhysicsQuest THE STANDARD MODEL