1. TO THE STANDARD MODEL particles and interactions The Physics studies the fundamental interactions among the elementary constituents of the matter. Constituents: bodies, fluids, particles Interactions: forces, fields Prof. Dr. Ion I. Cotaescu DISCRET PARTICLES CONTINUOUS WAVES

2. The first fundamental interaction Gravitation ideal point-wise particles Isaac Newton (1643-1727) Classical Mechanics INERTIA inertial frames Galileo Galilei (1564-1642) The Galilei transformations x’ = x – V t, t’ = t absolute frame

3. Electricity and Magnetism Michael Faraday (1791-1867) Magnetic induction Carl Friedrich Gauss (1777-1855) Electric flux Andre-Marie Ampere (1775 -1836) Magnetic effects of electric currents Hans Christian Ørsted (1777-1851)

4. James Clerk Maxwell (1831 -1879) predict the E-M waves discovered by Hertz in Heinrich Hertz (1857-1894) Electrodynamics The Maxwell equations 1887 oscillator receiver

5. The second fundamental interaction Electromagnetism electron Electric charges and currents elementary particles: Electromagnetic field (proton) Luminiferous ETHER ???? The EM radiation Electric field Magnetic field

6. Albert Michelson (1852 -1931) Edward Morley (1838-1923) The Michaelson and Morley experiment The ETHER does not exist Hendrik Lorentz (1853-1928) The Lorentz transformations 1887

8. The discovery of the atom structure 1909 nucleus Ernst Rutherford (1871-1937) Niels Bohr (1885-1962) Arno Sommerfeld (1868 -1951) Bohr’s model 1913 the fine structure of atomic spectra

9. Quantum Mechanics 1926 -1934 Louis de Broglie (1892-1987) the Davisson and Germer experiment Erwin Schrodinger (1887-1961) Werner Heisenberg (1901-1976) the fundamental equation of the Quantum Machanics uncertainty relations wave-particle duality

10. Wolfgang Pauli (1900-1958) electronic spin the Stern-Gerlach experiment Relativistic Quantum Mechanics positron Paul A. M. Dirac (1902-1984) predicting the antimatter Spin 1/2 Exclusion principle Dirac’s equation

11. The neutron and the nuclear reactions and fission 1932-1934 James Chadwick (1881-1974) Enrico Fermi (1901-1954) the role of the neutrino in beta decay - weak force proton neutron neutrino the first nuclear reactor Spin 1/2 Spin ½ (massless) Hideki Yukawa (1907-1981) strong nuclear forces

12. Four fundamental interactions Gravitation Electromagnetic interaction Weak nuclear forces (decay) Strong nuclear forces … an argument for unification…. Hadrons Leptons Elementary particles

13. Quantum interactions The consequences of the wave-particle duality: the elementary particles are field quanta matter fields gauge fields FERMIONS (spin ½) BOSONS (spin 1) DIRAC equation MAXWELL equation (electron/positron) (foton) GAUGE SYMMETRY Coupled through the U(1) Each type of conserved charge is given by a different symmetry em

14. Chen Ning Yang (1922) Tsung-Dao Lee (1926) New gauge symmetries Non-Abelian gauge fields Yang-Mills 1954 Parity non-conservation Robert Mills (1927-1999) U(1) SU(n) 1 charge n charges

16. Steven Weinberg (1933) Abdus Salam (1926-1996) Sheldom Glashow (1932) The Electro-Weak model SU(2) x U(1) 1970 - 1980 L

17. The Higgs mechanism of spontaneously breaking the gauge symmetry SU(2) x U(1) Peter Higgs (1929) L

18. leptons: neutrino, electron // positron Higgs field gauge bosons after the symmetry breaking the remaining symmetry is U(1) The theory of the gauge model SU(2) x U(1) L em

19. Quantum Chromodynamics Makoto Kobayashi (1944) Toshihide Maskawa (1940) Yoichiro Nambu (1921) The hadrons are constituted by quarks (antiquarks) : u, d, s, c, b, t The gauge particles are gluons SU(3) COLOR

20. The particles of the SU(3) QCD C quarks // antiquarks gluons Matter fields color // anticolor color - anticolor Gauge fields (strong forces) Fermions: Spin 1/2 Bosons: Spin 1 q = -1/3, 2/3 // 1/3, -2/3 massless and neutral massive with electric charges The color charges of the strong interaction (8 combinations) 2/3 -1/3 q = 0 etc…

21. Hadrons: baryons & mesons Baryons: Fermions Spin 1/2 Mesons: Bosons Spin 0

22. Standard Model SU(3) x SU(2) x U(1) Strong : gluon Weak : W, Z E-M : photon leptons interact E-M, W quarks interact E-M, W, S C L 3 generations L L

23. The masses of elementary particles Masa protonului ----- --- proton mass

24. Interactions – Feynman diagrams

25. THE STANDARD MODEL explains all the experimental data we know Unsolved problems 1. Where are the Higgs bosons? 2. Why the generations are independent ? 3. New particles may appear ? e.g. exotic quarks (with charges -4/3 and 5/3) or doubly charged bosons ?

26. Where we are…? New experimental data NON-RELATIVISTIC RELATIVISTIC SP. RELATIVISTIC G. CLASSICAL QUANTUM… Non-relativistic Classical Physics (mechaniacs E-M, etc....) Relativistic Classical Physics (relativistic classical fields) General relativity Cosmology Non-relativistic Quantum Mechanics Relativistic Quantum Fields Standard Model quantum gravity ? new sub -quantum level ? very high energies ? STRINGS ? M THEORY ?

27. The hope: The Large Hadron Collider (2010) principal ring - 27 km CERN

29. The detector ATLAS

30. We are waiting for new data Simulating the Hawking radiation (jets produced by the black-holes evaporation) ? Simulating a Higgs event ? ?