1. Particle Physics: building blocks of the universe Dr. James Catmore, Lancaster University Physics Dept.

2. 2 What is particle physics? The study of the basic constituents of matter and their interactions What is the Universe made of? How is it held together? People have been systematically studying matter for at least 2500 years 460BC: Concept of the atom is developed by Democritus 1803AD: Concept of the chemical element 1898: Measurement of the electron 1900: Birth of quantum mechanics 1911: Atomic nucleus is discovered; proton 1919, neutron 1931 1929: First cyclotron 1943: First nuclear reactor; nuclear weapons used in 1945 1946: Muon identified 1952: Bubble chamber invented 1968: First evidence for quarks 1974: Birth of the modern Standard Model 1983: Discovery of the W and Z bosons 1989: Discovery of the Top quark 2008: Switch-on of the Large Hadron Collider

3. 3 Current State of Knowledge

4. 4 The Quarks

5. 5 Current state of knowledge

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8. 8 Scale

9. 9 Unanswered questions What gives matter its mass? Why do ‘heavy’ quarks and leptons exist? Why are there so many particles? Are they really fundamental? Is there a more simple truth underpinning the Standard Model Where did all the antimatter go? How does gravity fit into particle physics?

10. 10 Through collisions of stable particles Through collisions of stable particles Energy is supplied using a particle accelerator Energy is supplied using a particle accelerator How do we obtain subatomic particles?

11. From cosmic rays.... You will see a cosmic ray detector today

12. 12 How do we study subatomic particles? Compu ter

13. 13 How do we study subatomic particles?

14. 14 How do we study subatomic particles?