2. The Standard Model of Particle Physics Piet Mulders mulders@few.vu.nl http://www.nat.vu.nl/~mulders http://www.wyp2005.nl Studiedag Natuurkunde en Sterrenkunde Feb. 10, 2005

3. The Standard Model of particle physics The particle content Experiments; matter and antimatter The fundamental forces Force carriers Central theme of Standard Model: symmetry The history of the universe Remaining questions in the standard model Mass and structure of space-time The mass in the universe Neutrinos

4. The particle content http://www.nat.vu.nl/~mulders P.J. Mulders home Theory Experiment Application

5. Materie MATTER A bit more or less Hydrogen in metals like Yttrium-Palladium (Griessen) REFLECTING TRANSPARENT

6. Materie MATTER ELECTRON ATOM 10 -10 m

7. The periodic table

8. Materie MATTER ELECTRON ATOM 10 -10 m MATTER ELECTRON ATOM 10 -10 m NUCLEUS 10 -14 m NEUTRINO ATOM 10 -10 m ELECTRON MATTER NUCLEUS 10 -14 m NEUTRINO NUCLEON proton/neutron 10 -15 m

9. Atomic nuclei Island of stability

10. Atomic nuclei Isotopes Radioactivity alpha beta gamma after 15 min.

11. Neutrinos more on neutrinos

12. Building blocks of the subatomic world

13. Materie ELECTRON MATTER ATOM 10 -10 m NUCLEUS 10 -14 m NEUTRINO NUCLEON proton/neutron 10 -15 m ELECTRON MATTER ATOM 10 -10 m NUCLEUS 10 -14 m NEUTRINO NUCLEON proton/neutron 10 -15 m QUARK up/down

14. Basic building blocks of matter home

15. How do we know this? http://www.nat.vu.nl/~mulders P.J. Mulders home

16. By using the largest microscopes on Earth

17. Antiparticles

18. Standard model content 3 particle families

19. The fundamental forces http://www.nat.vu.nl/~mulders P.J. Mulders home

20. Forces in daily life Electromagnetism Gravity Two of four basic forces Both based on fundamental principles

21. Standard model 3 particle families 4 fundamental forces strong force quark  nucleon  atomic nucleus electromagnetic force atom  molecule  complexity weak force decay gravity UNIFICATION more on gravity

22. Standard model 3 particle families 4 fundamental forces Corresponding force particles And a consistent theoretical framework: a renormalizable non- abelian gauge theory Steven Weinberg Sheldon Glashow Abdus Salam Gerard ‘t Hooft Martinus Veltman

23. How is the action of force particles http://www.nat.vu.nl/~mulders P.J. Mulders home

24. Force carriers of weak interactions Force particles play a role in: Interactions Pair creation Annihilation

25. Example: neutron decay Neutron beta-decay At the quark level n  p + e  + e d  u + e  + e

26. Three kinds of neutrinos! Z 0 decay into: quark pairs (except top quarks!) lepton pairs  e  e ,    ,      neutrino pairs (‘invisible’) lifetime is inverse of decay probability     i collission probability energy (GeV)

27. weak electromagnetic Strength of interactions G F ~  /M W 2 strong

28. How do quarks and gluons give the proton its properties? A one-line theory: QCD Massless quarks and gluons Protons and neutrons: Basic constituents of atomic nuclei forming 99.5 % of the visible mass in the universe

29. QED versus QCD This implies a constant force T 0 = 1 GeV/fm = 20 Ton Permanent confinement of colored quarks short distances large distances Frank Wilczek David Gross David Politzer

30. Mass of nucleon Almost massless quarks: m u ~ 5 MeV and m d ~ 10 MeV constant force T 0 = 1 GeV/fm leads to confinement of color over distances of ~ 0.8 fm Pressure in bubble: B ~ 100 MeV/fm 3  E V = 4  BR 3 /3 ~ 200 MeV Momentum p ~ 1/R ~ 250 MeV Energy per quark: E Q ~ 250 MeV Total energy: E ~ 940 MeV = mass of nucleon duuudd proton neutron

31. Phase diagram of QCD quark-gluon plasma hadrons nuclear matter T  ud

32. A model calculation  q (MeV) T (MeV) Harmen Warringa Daniël Boer

33. Central theme of standard model: SYMMETRY http://www.nat.vu.nl/~mulders P.J. Mulders home

34. Mirror symmetry Mirror world? Example: top Mirror world exist Conclusion: mirror symmetry is a symmetry of our daily world

35. Broken mirror symmetry A pion decays into spinning particles For a neutrino only one spin direction exist! But how can we measure this? spin + charge  magnet Only   observed at N-pole of the magnet! lefthanded For neutrinos there exist L but not R mirror images righthanded

36. CP symmetry Mirror symmetry (P) is broken in the subatomic world Particle-antiparticle symmetry (C) is also broken But … the combination is indeed a symmetry almost ___ K 0 = ds, K 0 = sd have slightly different masses and decay in a different way

37. CPT symmetry

38. Time reversal CPT is (to our present knowledge!) indeed a good symmetry of the world CP is almost a good symmetry Thus also time reversal is almost a good symmetry, but not exact! This symmetry breaking allows for the surplus of matter over antimatter in the universe (even if this is only 1 : 10 9 ) Number of baryons  0,25 x 10 79 (~ 0,25 per m 3 ) But the number of photons and neutrinos  10 88 (~ 400 per cm 3 ) more on mass in universe

39. CP-violation in standard model CP-violation can be implemented in the standard model through complex phase(s) in CKM-matrix. This requires at least three families! Cabibbo Kobayashi Maskawa

40. The history of the universe http://www.nat.vu.nl/~mulders P.J. Mulders home

41. BIG BANG 13.7 billion years ago

42. inflation

48. and finally now….

49. Remaining questions in the standard model 3 particle families 4 fundamental forces corresponding force particles Glimp of the ‘Higgs particle(s)’? … and very many questions remaining! (Anti)matter in universe ?? Black holes ? Space and time ? Points ? Strings ? Chaos ? Phase transitions ? Complexity Hadrons Why 3 families ?? Neutrinos ? Their masses ? http://www.nat.vu.nl/~mulders P.J. Mulders home

50. Where to find the answers? http://www.nat.vu.nl/~mulders P.J. Mulders home

51. In accelerators ? Collissions in the Large Hadron Collider at CERN –New particles (Higgs, …) –New symmetries (Fermion-Boson symmetry) –Origin of mass –Origin of symmetry breaking (e.g. CP-violation)

52. ATLAS CMS LHCb (future) detectors at CERN

53. Super Kamiokande Underground ?

54. Atmospheric neutrinos oscillate over thousands of kilometers Solar neutrinos change flavor in the Sun Masses m ~ 0.01 eV (that is extremely small, but compare k ~ 10  4 eV/K) Sudbury Neutrino Observatory (SNO)

55. In the mediterranean? or the ice? Looking for high energy cosmic neutrinos –Supernovae –Neutron stars –Black holes ANTARES AMANDA

56. Answers in the sky? Cold Dark Matter Dark baryonic matter (3.5%) Normal matter: stars (0.4%) Dark Energy Cosmic Accelaration 73% 23%

57. WMAP satellite 2.7248K2.7252K Angular Power Spectrum Cosmic microwave background

58. EINDE home

59. Mass and the structure of space-time http://www.nat.vu.nl/~mulders P.J. Mulders home

60. Mass: energy and momentum Velocity of light: c = 3 x 10 8 m/s = 300 000 km/s If v much smaller than c

61. Mass: gravity rotatiesnelheden in galaxies omloopstijden en afstanden (planeten, dubbelsterren) zwaartekracht versnelling a c bij cirkelbeweging zware massa trage massa =

62. Mass: curvature of space-time Zonder kracht: rechtlijnige beweging Zwaartekracht wordt veroorzaakt door massa Massa bepaalt ook mate van respons (equivalentieprincipe) Algemene relativiteitstheorie: Beweging in zwaartekrachtveld is rechtlijnige beweging in een t.g.v massa gekromde ruimte GEEN KROMMINGPOSITIEVE KROMMING NEGATIEVE KROMMING

63. curvature Kromming van een bol: k = 1/R 2 Bijv voor voetbal: k = 50 /m 2 Bijv voor aarde: k = 2.8 x 10 -14 /m 2 Andere methode gaat via hoeken k =  /S(  )

64. The boomerang experiment 2 terra-cruisers back and forth!

65.  R = 42 min = 7.5 x 10 11 m of  = 20 m/s = 0.67 x 10 -7 R = (16 km)/  = 2.4 x 10 11 m k = 1/R 2 = 1.6 x 10 -23 /m 2 !!! Vergelijk met ‘bol’: space-time curvature home 1 s = 3 x 10 8 m

66. http://www.nat.vu.nl/~mulders P.J. Mulders home The matter in the universe

67. Matter in the universe Cold Dark Matter Dark baryonic matter (3.5%) Normal matter: stars (0.4%) Dark Energy Cosmic Accelaration 73% 23%

68. Evidence for Dark Matter Rotation of galaxiesGravitational lensesMicrowave background

69. Ultra High Energy Cosmic Rays Data beyond the GZK limit: new physics? CMB pion E E’

70. Neutrinos http://www.nat.vu.nl/~mulders P.J. Mulders home

71. Origin of neutrinos Weak decay of atomic nuclei (Sun/reactors): …n…  …p… + e  + e ( righthanded antineutrino ) …p…  …n… + e + + e ( lefthanded neutrino ) Cosmic rays (decay of the pion)      +  ( righthanded antineutrino )  +   + +  ( lefthanded neutrino ) Remnants of the big bang just as photons (T = 2.7 K background) for all three kinds of neutrinos ( e,  en  ) about 400 per cm 3

72. Questions around neutrinos What are the masses of neutrinos Where are the neutrinos from the Sun? Half of them is missing!

73. How to detect neutrinos?

74. Neutrino detectors Sudbury Neutrino Observatory (SNO)

75. Detection via cherenkov light emitted by particles moving “faster” than light (from antares experiment) Neutrino detection techniques

76. Neutrino detectors Super Kamiokande

77. Neutrino oscillations in the atmosphere Neutrinos in the atmosphere are created in the decay of pions. These are mainly  neutrinos If the  neutrino is a quantummechanical superposition of two neutrinos 1 en 2 it gives rise to oscillations Place and time of measurement Place and time of production

78. Neutrino oscillaties in atmosfeer Superkamiokande showed oscillations depending on the distance L to the detector Oscillation-wavelength is thousands of kilometers  mass smaller than 0.000 001 of that of the electron Nature of oscillations is   

79. Consequences of mass Particles with mass must come as righthanded and lefthanded! This is only possible if the neutrino is its own anti- particle (as the photon, but unlike the electron)

80. Dirac and Majorana neutrinos Fermion (general) P = spiegelen C = deeltje-antideeltje T = tijdomkeer

81. Dirac and Majorana neutrinos Dirac neutrino

82. Dirac and Majorana neutrinos Majorana neutrino

83. Neutrino oscillations in the Sun Oscillations arise because the interaction of e with matter differs from the interaction of  ( e ‘feels’ electrons,  doesn’t!) SNO showed that what is missing on e appears as a different kind of neutrino Most probably these are oscillations of the type e  

84. Neutrino mixing Mixing pattern of neutrinos as for quarks with possibly also complex phases and CP violation