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Black Holes, the LHC and the God Particle Dr Cormac O’Raifeartaigh (WIT) The Big Bang, the LHC and the God Particle Cormac O’Raifeartaigh (WIT) Overview I. LHC What, why, how II. A brief history of particles From the nucleus to the Standard Model III. LHC Expectations The God particle Beyond the Standard Model Cosmology at the LHC E = mc2 The Large Hadron Collider (CERN) Particle accelerator Head-on collision of protons Huge energy density Create short-lived particles Detection No black holes Why I. Explore fundamental constituents of matter Investigate inter-relation of forces that hold matter together II. Study early universe Highest energy since BB T = 1019 K t = 1x10-12 s V = football • Puzzle of antimatter • Puzzle of dark matter Cosmology E = kT → T = How Ultra-high vacuum Low temp: 1.6 K v = speed of light E = 14 TeV (2.2 µJ) LEP tunnel: 27 km Superconducting magnets 600 M collisions/sec (1.3 kW) Particle detectors 4 main detectors • CMS multi-purpose •ATLAS multi-purpose •ALICE quark-gluon plasma •LHC-b antimatter decay UCD group Particle detectors Tracking device measures momentum of charged particle Calorimeter measures energy of particle by absorption Identification detector measures velocity of particle by Cherenkov radiation Matter and Energy Matter is a form of energy E = mc2 Energy is a form of matter m = E/c2 → Create matter and antimatter from energy Antimatter Predicted by Dirac Equation Electron of opposite charge Detected 1932 All particles have opposites Why is universe dominated by matter? Black Holes • Huge mass shrunk to tiny volume • Extreme gravitational field • Light, matter ‘trapped’ Huge energy required m = E/c2 II Particle physics (1930s) • Atoms (1909) Brownian motion • The atomic nucleus (1911) Rutherford Backscattering • Proton (1918) • Neutron (1932) Protons and the Periodic Table • Fundamental differences in atoms no. protons in nucleus • Determines electron configuration • Determines chemical properties What holds nucleus together? What causes radioactivity? Strong force (Yukawa, 1934) strong force >> em charge indep (p+, n) short range Heisenberg Uncertainty massive particle 3 charge states Yukawa pion (1947) Yukawa Weak force (Fermi, 1934) Radioactivity (B decay) Electrons from nucleus? no p+ + e- ? But: energy, momentum missing New particle; tiny mass, zero charge neutrino no p+ + e- + (confirmed 1956) Four forces of nature Force of gravity Holds cosmos together Long range Electromagnetic force Holds atoms together Strong nuclear force: holds nucleus together Weak nuclear force: Beta decay Walton: accelerator physics Cockcroft and Walton: linear accelerator Protons used to split the nucleus (1932) 1H 3Li 2He + 2He + → 1 6.9 4 4 Verified mass-energy (E= mc2) Verified quantum tunnelling Nobel prize (1956) Cavendish lab, Cambridge New particles (1950s) Cosmic rays π+ → μ+ + ν Particle accelerators LINACS (Walton) synchrotrons Particle Zoo (1950s, 1960s) Over 100 particles Quarks (1960s theory) p not fundamental new periodic table symmetry arguments new fundamental particles quarks Up, down, strange prediction of - Gell-Mann, Zweig Quarks (experiment, 1970s) Stanford experiments 1969 Scattering experiments Similar to RBS SF = interquark force! defining property = colour confinement infra-red slavery The energy required to produce a separation far exceeds the pair production energy of a quark-antiquark pair Quark generations (1970s –1990s) 30 years experiments Six different quarks (u,d,s,c,t,b) Six leptons (electron sisters) (e, μ, τ, υe, υμ, υτ) Gen I: all of ordinary matter Gen II, III redundant? Electro-weak force (1970s) Electromagnetic + weak forces = e-w force Single interaction above 100 GeV Mediated by new particles W, Z Higgs mechanism to generate mass Predictions: Detected: W+-,Z0 bosons CERN, 1983 Rubbia, Van der Meer Nobel prize 1984 Glashow, Salaam and Weinberg Nobel prize 1979 The Standard Model (1970s) EM + weak force = electroweak Strong force = quark force (QCD) Force between quarks caused by colour Matter particles: fermions Force particles: bosons Standard Model: 1980-1990s • experimental success but Higgs boson outstanding key particle: too heavy? III LHC expectations (SM) Higgs boson Determines mass of other particles Set by known mass of top quark, Z boson 120-180 GeV Search…surprise? Main production mechanisms of the Higgs at the LHC Ref: A. Djouadi, hep-ph/0503172 Higgs search: summary Ref: hep-ph/0208209 Expectations II: Beyond the SM Unified field theory Grand unified theory (GUT): 3 forces Theory of everything (TOE): 4 forces Supersymmetry symmetry of fermions and bosons improves GUT (circumvents no-go theorems) gravitons: makes TOE possible LHC Supersymmetric particles? Extra dimensions? Expectations III: Cosmology 1. Superforce: SUSY particles? 2. SUSY = dark matter? neutralinos? double whammy 3. Missing antimatter ? LHCb High E = photo of early U LHCb (UCD) • Where is antimatter? • Asymmetry in M/AM decay • CP violation Tangential to ring B-meson collection Decay of b quark, antiquark CP violation (UCD group) b-quarks, W,Z bosons June 2010 Summary Higgs boson (God particle) Close chapter on SM Supersymmetric particles Open chapter on unification Cosmology Missing antimatter Nature of dark matter Surprises New dimensions - string theory? Further reading: ANTIMATTER Epilogue: CERN and Ireland European Organization for Nuclear Research World leader 20 member states 10 associate states 80 nations, 500 univ. Ireland not a member No particle physics in Ireland…..almost