2. 1  High energy particles have extremely small wavelengths and can probe subatomic distances: high energy particle accelerators serve as super-microscopes.  The higher the energy the closer particles can come to each other, revealing the smaller details of their structure.  The energy of the collisions produces new particles : E=mc 2 The higher the energy the heavier the new particles that can be created. Particle Physics - High Energy Physics

3. 2 like smashing two cars together and getting a bulldozer out

4. 3

5. 4 21 st century particle physics (e.g.) Fermilab’s Tevatron is the highest energy accelerator in the world today. antiprotons Beams of protons collide with beams of antiprotons

6. 5 antimatter  particle accelerators create antimatter by smashing high energy particles onto metals  the total amount of antimatter produced in particle accelerators per year ~ 1 microgram  even one microgram of antimatter would provide enough energy to drive your car for a month (E=mc 2 )

7. 6 no mass?  Yes, photons are massless  We thought neutrinos were massless too  In 1998 underground experiments discovered that neutrinos have tiny masses The SNO detector is more than a mile underground

8. 7 extra dimensions? 6? 7?32? String theory demands extra dimensions. Experiments can actually discover them!

9. 8 positron in cloud chamber detection of high energy particles

10. 9 Pion picture in a streamer chamber; gas glows brightly along the tracks of the particles.   e

11. 10 “ I remember in 1949, on a bulletin board at the Princeton Institute for Advanced Study, a photomicrograph of a nuclear emulsion event, showing what is now known a a K-meson decaying into three pions. We all saw it. No doubt that something interesting was going on, very different from what was then known, but it was hardly discussed because no one knew what to do with it” Jack Steinberger

12. 11

13. 12 1 st circular accelerator (11 inches!) (11 inches!)  uses both electric and magnetic fields.  particles orbit in circles Lawrence and Livingston built the first cyclotron in 1932. It was about 30 cm across, in a magnetic field of about 5000 Gauss and accelerated protons to roughly 1.2 MeV

14. 13 professor’s view

15. 14 mechanical engineer’s view

16. 15 computer scientist’s view

17. 16 theoretical physicist’s view

18. 17 visitor’s view

19. 18 LBL McMillan Lawrence Synchro-cyclotron, Betatron, synchrotron

20. 19 3 GeV protons Brookhaven National Laboratory(1952) Cosmotron

21. 20  Strong Focusing (1952)  Colliding Beams (60s)  Superconducting magnets (80s)  Stochastic Cooling (80s) major invasions in accelerator technology

22. 21 P2K/NASATV movie excerpt

23. 22 After the pion a plethora of new particles called hadrons were discovered in accelerators

24. 23 the Big picture The universe is made out of matter particles and held together by force particles fermions bosons quarks leptonsgauge bosons graviton

25. 24 Feynman Graph The electron and quark interact electromagnetically by the exchange of a photon. The lines, wiggles and vertices represent a mathematical term in the calculation of the interaction.

26. 25 Quantum Weirdness  The interactions of particles obey the rules of quantum mechanic and of special relativity quantum fields  And particles aren’t really particles, they are quantum fields   The fermions (quarks and leptons) are especially weird…

27. 26 G u e s G u e s

28. 27 the Model precisely After 50 years of effort, we have a quantum theory which explains precisely how all of the matter particles interact via all of the forces — except gravity. For gravity, we still use Einstein’s General Relativity, a classical theory that has worked pretty well because gravity effects are so weak. What is a model?

29. 28 the Standard Model a list of particles with their “quantum numbers”, about 20 numbers that specify the strength of the various particle interactions, a mathematical formula that you could write on a napkin.

30. 29 g

31. 30 g

32. 31 g

33. 32 g

34. 33

35. 34 hierarchy of scales 10 -33 cm Planck scale 1/(M Pl ) 2 G N ~l Pl 2 = 1/(M Pl ) 2 10 -17 cm Electroweak scale range of weak force mass is generated (W,Z) strong, weak, electromagnetic forces have comparable strengths 10 28 cm Hubble scale size of universe l u 16 orders of magnitude puzzle What kind of physics generates and stabilizes the 16 orders of magnitude difference between these two scales 10 27 eV 10 11 eV 10 -33 eV

36. 35 unification of couplings The gauge couplings of the Standard Model converge to an almost common value at very high energy. what’s up with that?

37. 36 what does the Standard Model explain ? your body  atoms  electrons  protons, neutrons  quarks

38. 37 what does the Standard Model explain ?

39. 38 neutrino ( ) sky

40. 39 what does the Standard Model explain ?

41. 40 what does the Standard Model not explain ? HST image of an 800 light-year wide spiral shaped disk of dust fueling a 1.2x10^9 solar mass black hole in the center of NGC 4261  quantum gravity

42. 41 what does the Standard Model not explain ?  quantum gravity  dark matter and dark energy

43. 42 what does the Standard Model not explain ?  quantum gravity  dark matter and dark energy  Higgs Arrange it so delicately that it will fall down in 19 minutes.

44. 43 the Bigger Big picture The Standard Model describes everything that we have seen to extreme accuracy.

45. 44 Now we want to extend the model to higher energies and get the whole picture the Bigger Big picture For this we need new experiments and ideas supersymmetry strings (even) extra dimensions

46. 45 matter antimatter Dirac (1928) special relativity & quantum mechanics

47. 46 fermions bosons supersymmetry (SUSY) every particle has a superpartner particle

48. 47 fermions bosons supersymmetry every particle has a superpartner particle

49. 48 fermions bosons supersymmetry electron selectron quark squark photino photon gravitino graviton  most of the dark matter in the universe maybe the lightest sparticle  none of the sparticles have been discovered yet

50. 49 unification of couplings Ø SUSY changes the slopes of the coupling constants ØFor M SUSY =1 TeV, unification appears at 3x10 16 GeV

51. 50

52. 51 HST image of an 800 light-year wide spiral shaped disk of dust fueling a 1.2x10^9 solar mass black hole in the center of NGC 4261  quantum gravity what do explain ?

53. 52  require 7 extra space dimensions  and give us ways to hide them

54. 53 compactification

55. brane-worlds Standard Model particles are trapped on a brane and can’t move in the extra dimensions There could be other branes which would look like dark matter to us

56. 55 how do we see a hidden dimension? ? what particles can move in that dimension ? how big is that dimension ? what is its shape some dimensions are easier to detect than others slice of a 6 dimensional Calabi-Yau space

57. 56 gravitons are the most robust probe of extra dimensions gravity is so weak that we have never even seen a graviton. The gravitational attraction between two electrons is about 10 42 times smaller than the electromagnetic repulsion. F=G N m electron r 2 r m electron

58. 57 gravity gets stronger at extremely high energies (or short distances). force strength energy 4d gravity (4+n)d gravity it gets stronger at lower energies if there are extra dimensions…. think about this:

59. 58 gluon (becomes “jet” of hadrons) graviton quark antiquark …in which case high energy gravitons may be produced in collider experiments: these gravitons probably “escape” these gravitons probably “escape” into the extra dimension(s) into the extra dimension(s)

60. 59 graviton emission simulation:  we don’t see the graviton  we see a jet from the gluon

61. 60 Collider Detector at Fermilab

62. 61

63. 62 concentric cylindrical layers energy deposited from the particle debris of the collision in the middle

64. 63 “lego” event display

65. 64 Two events are graviton simulation and one is real CDF data: Can you pick the gravitons?

66. 65 two events are real CDF data and one is graviton simulation; Can you pick the graviton?

67. 66 Higgs simulation

68. 67 Large Hadron Collider (CERN, 2006) new accelerators for new physics Linear Collider (?,~2012)

69. 68 underground and in the sky SuperNova Acceleration Probe (SNAP)

70. 69 underground and in the sky KamLAND neutrino detector

71. 70 The coming experiments in particle physics, cosmology and astrophysics will answer (among many other questions) what is the physics that connects the gravitational scale and the scale of the typical mass of the elementary particles what is dark energy and what is dark matter do protons decay what is string theory what are the dimensions and dynamics behind spacetime

72. 71 If you ask questions about what happened at very early times, and you compute the answer, the answer is: Time doesn’t mean anything. S. Coleman Space and time may be doomed. E. Witten I am almost certain that space and time are illusions. N. Seiberg The notion of space-time is clearly something we’re going to have to give up. A. Strominger

73. 72 …for any important assertion evidence must be produced; …prophecies and bugaboos must be subjected to scrutiny; … guesswork must be replaced by exact count; ….accuracy is a virtue and inquiry is a moral imperative. To the hegemony of science we owe a feeling for which there is no name, but which is akin to the faith of the innocent that the truth will out and vindication will follow. In its purest form science is justice as well as reason. Jacques Barzun SCIENCE: The Glorious Entertainment

74. 73

75. 74 wednesday lunch oct 9 2002 maria spiropulu “let there be light” is what we say when the experiment starts taking data ; usually in particle physics and astronomy/cosmology