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of quarks and leptons

flavor mixing. of quarks and leptons. quarks * leptons. reduced by 80 %. N. Cabibbo 1963 ( Cabibbo angle ). hypothesis: new (fourth) quark „charm“. 1970 GIM – mechanism ( Glashow, Iliopoulos, Maiani ). c: charmed quark.

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of quarks and leptons

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  1. flavor mixing of quarks and leptons quarks * leptons

  2. reducedby 80 %

  3. N. Cabibbo 1963 ( Cabibbo angle )

  4. hypothesis:new (fourth) quark „charm“

  5. 1970GIM – mechanism( Glashow, Iliopoulos, Maiani ) c: charmed quark

  6. November 1974: discoveryofthecharmedquark

  7. SLAC J/PSI e(+) e(-) M= 3.1 GeV

  8. SLAC MIT November 1974

  9. - flavor mixing angles fermion masses

  10. - - III 2 families flavor mixing II I

  11. (Cabibbo angle)

  12. mass matrices texture 0 u,c - d,s H. Fritzsch S. Weinberg 1978

  13. texture zeros in the electroweak gauge group SU(2,L) x SU(2,R) x U(1)

  14. SU(2,L) x SU(2,R) x U(1) grand unification SO(10)

  15. U(1) x U(1) symmetry

  16. - ==> mass matrix

  17. - mixing angles <=> masses

  18. Cabibbo angle Exp.: phase 90 degrees ( symmetry ! )

  19. Cabibbo angle ==>

  20. 1977: Fermilabb-quark

  21. CDF – detector Fermilab

  22. M(b) : ~ 4.2 GeV

  23. 1995 - FNAL t mass (t): 172.0±2.2 GeV

  24. - III 3 families II I

  25. Masses - Charged leptons and quarks (MeV) tau: 1 777 muon: 105.7 electron: 0.51 - t: 173 000 c: 1 200 u: 5.3 b: 4 300 s: 130 d: 7.8 (u, d, c, s - quark masses at 1 GeV)

  26. relations between quark masses ? • Observed: m(c) : m(t) = m(u):m(c) 1/207 1/207 m(s):m(b) = m(d):m(s) 1/23 1/23

  27. ln m

  28. - flavor mixing => CKM - matrix: three angles - one phase

  29. CKM matrix standard parametrization

  30. New parametrization: H. F. - Z. Xing

  31. - texture zeros:

  32. -

  33. - The angles and can be measured separately.

  34. SLAC DESY KEK FNAL CERN

  35. theory - x x theory -

  36. - unitarity triangle

  37. - - -

  38. Cabibbo angle Unitarity triangle (rectangular)

  39. Experiment:alpha 89.0 + 4.1/-4.2 degrees

  40. - Maximal CP-violation

  41. Unitaritytriangle:

  42. flavor mixing leptons

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