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.

What is fundamental?

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.

What is the world made of?

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.

What holds it together?

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.

How do we detect what's happening?

18. Explain how physicists apply the concepts of momentum

     and wavelength to study particles.

PART IV.

How do we experiment with tiny particles?

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