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Re-creating the Big Bang. Experiments at the Large Hadron Collider. Dr Cormac O’ Raifeartaigh (WIT). Overview. I What II Why III How IV A brief history V Beyond the Standard Model. A particle accelerator ‘Atom smasher’ Particles created Detected.
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Re-creating the Big Bang Experiments at the Large Hadron Collider Dr Cormac O’ Raifeartaigh (WIT)
Overview I What II Why III How IV A brief history V Beyond the Standard Model
A particle accelerator ‘Atom smasher’ Particles created Detected I The Large Hadron Collider LHC at CERN, Geneva
How High speed proton beams Opposite directions - collisions Huge energy of collision Create short-lived particles Detection and measurement
27 km Energy: 14 TeV Low temp: 1.6 K Ultra high vacuum HOW
Explore fundamental constituents of matter Investigate forces that hold matter together Glimpse of early universe Highest energy since BB Why Are the forces of the universe related ?
Newton (1642-1727) Newton’s gravity • Planet orbits due to gravity • Gravity caused by sun’s mass • Terrestrial gravity due to earth’s mass
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: radioactivity The atom
Atoms: chemistry • Democritus (600 BC): matter made of atoms • Dalton (19th ct): • Mendeleev (19th ct): chemical reactions
Atoms: physics • Maxwell (19th ct): atomic theory of gases • Einstein: (1905): Brownian motion due to atoms? • Perrin (1908): verified Brownian motion Perrin Einstein
The atomic nucleus • Most projectiles through • A few deflected backwards • Atom has nucleus • Electrons outside Rutherford (1911)
Nuclear model of the atom Atom • Nucleus (+ve): • Electrons (-ve): orbiting • Force: electromagnetic Nucleus • Protons (1909) • Nucleus (1911) • Neutrons (1932)? nNu Nuclear force: stronger than electromagnetic?
Splitting the nucleus Cockcroft and Walton: particle accelerator Particles used to split the nucleus (1932) He + Li = Nobel prize (1956)
Nuclear fission • Meitner, Hahn: nuclear fission • Huge energy released • Chain reaction • Nuclear bomb • Nuclear power • Nuclear power stations
New particles • Cosmic rays New particle accelerators cyclotron
108 particles New periodic table Not fundamental Inner structure Symmetry arguments Quarks The quark model Murray Gellmann
Six different quarks (u,d,s,c,t,b) Six leptons (e,μ,τ, υe,υμ,υτ) Particles of matter: fermions Two extra generations Quarks and leptons
Matter: leptons and quarks Force carriers: bosons The Standard Model • EM + weak = electroweak • Stong force = quark force Higgs field Particle masses Higgs boson
Higgs boson 120-180 GeV Set by mass of top quark, Z boson LHC and the standard model
Unification of 3 forces Grand unified theory Supersymmetry Supersymmetric particles? Unification of 4 forces Theory of everything String theory Extra dimensions Beyond the standard model
LHC and cosmology √ 1. Exotic particles 2. Mini BB = photo of early U 3. Nature of dark matter? 4. Missing antimatter 5. Superforce
Higgs boson Close chapter on SM Supersymmetric particles Open chapter on unification WIMPS Explain Dark Matter Unexpected particles Revise theory low temperature 3. Summary: expectations
20 member states 10 associate states Ireland not a member Epilogue: CERN Organization for Nuclear research No particle physics in Ireland