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H. Fritzsch. quantum chromo dynamics electroweak gauge theory.

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Presentation on theme: "H. Fritzsch. quantum chromo dynamics electroweak gauge theory."— Presentation transcript:

1 H. Fritzsch

2 quantum chromo dynamics electroweak gauge theory

3

4 Special quantum relativity mechanics

5 Standard Theory particle physics

6 1936 => matter atoms electrons + nuclei

7 Proton Electron

8 nucleus protons neutrons

9 electric force strong force

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11 1935 Heisenberg / Pauli

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13 1935 strong interactions - meson exchange - Hideki Yukawa meson

14 mass: 140 MeV nucleon

15 1932 Heisenberg Isospin

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17 pions: triplet eta: singlet

18 weak decay  elm. decay 

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20 LBL Berkeley Golden gate

21 1953 pion nucleon

22 delta quadruplet 1230 MeV

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24  1 discovery of new particles in cosmic rays Hyperons K-mesons

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26 pair production

27 6 hyperons

28 8 baryons

29 new mesons

30 8 mesons

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33 strangeness conserved in processes of strong interactions

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37 strangeness not conserved in processes of weak interactions

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39 S conserved elm. process S=-2  S=-1

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42 8 baryons

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44 8 mesons => octet

45 Isospin breaking about 1% _______________________________ SU(3)-symmetry breaking about 20% !

46 Group theory

47 U(n) group of complex unitary n x n matrices SU(n) n x n matrices det U = 1

48 U = exp (iH) H: Hermitean n x n matrix

49 det U = exp i (trH) SU(n): det U = 1 tr H = 0

50 SU(n) (n x n-1) generators SU(2): 3 SU(3): 8 SU(4): 15 SU(5): 24

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57 structure constants

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59  quarks triplet  fundamental representation

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62 quark triplet

63 steps p / q irreducible representations

64 each state is described by 3 numbers:

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72 1232 MeV 1530 MeV 1385 MeV Decuplet ???

73 Decuplet ?

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75 mesons singlets, octets baryons singlets, octets, decuplets triplets? sextets?

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77 77

78 Three quarks for Muster Mark! Finnegans Wake, page 383

79 Three quarks for Muster Mark! Drei Mark für Musterquark!

80 SU(3)

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83 Symmetry breaking quark masses m(u)=m(d)=m(s)  SU(3) unbroken

84 m(u): 5 MeV m(d): 7 MeV m(s): 110 MeV  SU(3) broken

85 m(u): 5 MeV m(d): 7 MeV m(d) > m(u)  isospin broken by quark masses m(neutron) > m(proton) !!!

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87 87

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90 strangeness: - minus number of strange quarks !

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108 scaling behaviour cross section

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111 partons quarks

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113 current commutators near the light cone abstracted from free quark model  explains scaling behaviour

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115 115 1 x x = quark-momentum / proton-momentum Expected: x => 1/3

116 observed

117 1974 : SPEAR Stanford

118 J/ψ

119 electron-positron-annihilation J/ψ: 3,1 GeV

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122 c: Charm - Quark

123 D-mesons ( masses ~ 1870 MeV )

124 D-mesons decay: weak interactions

125 1977 Fermilab discovery Y „upsilon“

126 upsilon meson (ϒ) 9.46 GeV ϒ=ϒ=

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128 128

129 discovery of t-quark

130 CDF-detector

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133 t-quark gold atom

134 t-quark decay very fast no time to form a hadron => No T-mesons No T-baryons

135


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