Re-creating the Big Bang Experiments at the Large Hadron Collider Dr Cormac O’ Raifeartaigh (WIT) Albert Einstein Ernest Walton
Overview I What II Why IIIHow IV A brief history of atoms V Expectations
I The Large Hadron Collider A particle accelerator ‘Atom smasher’ Particles created Detected LHC at CERN, Geneva
How High speed proton beams Opposite directions - collisions Huge energy of collision Create short-lived particles Detection and measurement E = mc 2
HOW 27 km Energy: 14 TeV Low temp: 1.6 K Ultra high vacuum
Why Explore fundamental constituents of matter Investigate forces that hold matter together Glimpse of early universe Highest energy since BB Are the forces of the universe related ?
Gravity caused by sun’s mass Newton ( ) Planet orbits due to gravity Newton’s gravity 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
A brief history of atoms Democritus (600 BC):matter made of atoms Dalton (19 th ct): Mendeleev (19 th ct): chemical reactions
A brief history of atoms Maxwell (19 th ct):atomic theory of gases Einstein: (1905):Brownian motion due to atoms? Perrin (1908):verified Brownian motion Einstein Perrin
The atomic nucleus Most projectiles through A few deflected backwards Atom has nucleus Electrons outside Rutherford (1911)
Nuclear model of the atom nNunNu Nucleus (+ve): Electrons (-ve): orbiting Force: electromagnetic Protons (1909) Nucleus (1911) Neutrons (1932)? Atom Nucleus Nuclear force: stronger than electromagnetic?
Splitting the nucleus Cockcroft and Walton: particle accelerator Particles used to split the nucleus (1932) Nobel prize (1956) H + Li = He + He Verified mass-energy (E= mc 2 ) Verified quantum tunnelling
Nuclear fission Meitner, Hahn: nuclear fission Energy released Chain reaction Nuclear bomb Nuclear power Nuclear power stations
New particles Cosmic raysNew particle accelerators cyclotron
Particle Zoo Over 100 particles
The quark model New periodic table New fundamental particle Proton not fundamental Inner structure Symmetry arguments Quarks Murray Gellmann
Quarks and leptons Six different quarks (u,d,s,c,t,b) Six leptons (e, μ, τ, υ e, υ μ, υ τ ) Particles of matter: fermions Two extra generations
The Standard Model Matter: leptons and quarks Force carriers: bosons EM + weak = electroweak Strong force = quark force Higgs field Particle masses Higgs boson
LHC: expectations Higgs boson GeV Set by mass of top quark, Z boson Explain masses for other particles
Beyond the standard model Unification of 3 forces Grand unified theory Supersymmetry Supersymmetric particles? Unification of 4 forces Theory of everything String theory Extra dimensions
LHC and cosmology √ 1. Exotic particles √ 2. Unification of forces 3. Nature of dark matter? 4. Missing antimatter? LHC = photo of early U
3. Summary Higgs boson Close chapter on SM Supersymmetric particles Open chapter on unification WIMPS Explain Dark Matter Unexpected particles Revise theory
Epilogue: CERN World centre for particle physics 20 member states 10 associate states Ireland not a member No particle physics in Ireland Organization for Nuclear research