2. Targets of our work group Simple lessons with BC photographs History of BC Overview of 50-minutes lesson FAQs

4. To create simple lesson with BC photographs To update webpage on history of BC To create 50 minutes modular lesson for teaching BC concepts To create webpage of frequently-asked questions (FAQs)

6. You can make your own cloud chamber and see tracks of particles produced by cosmic rays Click here for instructionshere When a charged particle goes through a superheated liquid, it ionises atoms along its path and makes the liquid boil, creating a trail of bubbles Click here for a simulation of bubble formationhere

7. A plane in the sky causes water vapour in the air to condense Charged particle in BC causes superheated liquid to boil

8. The different coloured tracks are produced by different charged particles – Bright Green kaon K  – Red electron e  – Blue proton p Why are tracks curve? Click here for discussionhere

9. A particle of charge q travelling through a magnetic field B with a velocity v experiences a force, given by We use the formula for the Lorentz force to calculate the value and direction of the force exerted on charged particles by the magnetic field

10. The thumb points in the direction of the force F First finger points in the direction of the magnetic field B Second finger points in the direction of motion of the positive charge v

11. In principle, the momentum of a charged particle is obtained using the formula

12. Spiralling tracks are common in BC photographs, caused by e  or e + An e  loses energy at a considerable rate as it travels through BC liquid All other charged particles, unless they collide with a nucleus, slow down very gradually – get more curved – as they lose energy by ionisation

13. e  are able to lose energy more quickly by another process in which all accelerated charges radiate Click here for more informationhere

15. Dark tracks belong to a slow particle Spiralling tracks are because of their very small mass Spiralling tracks are e  because of their very small mass

16. Particles with large momenta are less curved Particles with small momenta are more curved

17. All physical laws must be fulfilled in every BC event – Momentum conservation – Charge conservation – Energy conservation – Behaviour of moving charged particles in magnetic field – Other physics laws

18. The primary (orange) beam has –ve charge while one of the two secondary beams has –ve charge (green) and the other +ve charge (bright green) We also know that the two outgoing tracks have low momentum because they curve significantly in B-field

19. What is the direction of the momentum of the primary beam?

20. Estimate the momenta of the secondary tracks What is the total momentum after interaction?

21. Clearly the total momentum of the outgoing charged particles does not equal to the momentum of the beam particle Draw an arrow to show the “missing” momentum Click here for more infohere

22. In all BC photographs, the charge of the particle can be only +e or  e Sign of particles can be determined by the direction of the track’s curvature

23. Click here to find thishere The primary beam is K  What are the charges of secondary particles? [Hint: the red spiral is produced by an electron] Green is negative and bright green is positive

24. If this event do not involve other particle, total charge before interaction (  e) is not equal to the total charge after it (0) But the collision involves a proton (+e), so the total charge is conserved

25. Here is another picture that could be used for a similar exercise Here

27. Improve and publish a webpage on history of BCwebpage – Birth and evolution of BC and its main discoveries – Important photographs – 2 articles on history of BC and personal experience PowerPoint on history of BC

28. Cloud chamber Anderson (1932), positron (e + ) Nuclear Emulsion Powell (1947), pion   

29. It’s faster to reactivate than cloub chambers The expansion of BC can coincide with the accelerator cycle BC were very small initially; only a few cubic centimetre of liquid Big European Bubble Chamber (BEBC) in 70’s has a diameter of 3.7 m

30. 1956. Discovery of  0 in a propane BC 1964. Discovery of   which gives acceptance of Gell- Mann theory of ordering all subatomic particle “eight- fold way” 1973. Neutral current discovered at CERN’s 25-ton Gargamelle 1975. Discovery of “charmed” baryon in 7-foot Brookhaven

31. Research on earlier particle detectors – cloud chamber & nuclear emulsions Design a PowerPoint presentation using the contents of the webpage Short biographies of the people who developed the BC

33. Lesson 1 – “Introduction to BC and Basic Feature of the Interactions” Lesson 1 – Photographs, Worksheet 1 PhotographsWorksheet 1 Lesson 2 – “Identifying the Particles and Conservation of momentum & Charge” Lesson 3 – “Particle Interactions – Collisions & Decays” Lesson 4 – “Principle of determination of momentum”

34. Lesson 5 – “Principle of determination of energy” Lesson 6 – “More complex BC photographs”

36. What does LHC stand for? Large Hadron Collider. Click here for further detail.here What are antiparticles? To every particle that has a non-zero value of some quantity such as electric charge, it is possible to create another particle with the opposite value – this is the antiparticle of the original one. For an example, click here. here

38. Profile of Jonni FulcherJonni Fulcher An example of a collisioncollision Jonni Fulcher Stunts You may need to install the xvid codec - you can download it from herehere