Lectures recorded at : cern.ch/wlap

1. Lectures recorded at : http://www.cern.ch/wlap Egil Lillestøl, CERN & Univ. of Bergen

2. Physics at the LHC 2. What did we get from LEP ? Egil Lillestol, 8 February 2001 Egil Lillestøl, CERN & Univ. of Bergen

3. Can not use light microscopes to study atoms !!! Quantum mechanics tells us that particles behave like waves and visa versa: electron l =h/p Use electron microscopes LEP the world’s biggest electron microscope Egil Lillestøl, CERN & Univ. of Bergen

4. High Energy electron-proton scattering quark electron Jet of Particles New Stuff fromE=Mc2 New, unstable particles, can NOT be explained as made of up and down quarks only. Egil Lillestøl, CERN & Univ. of Bergen

5. Practical Units U=1 eV = 1.6x10-19J (speed at positive plate 18 000 km/s) electron (energy U) 1 keV = 103 eV 1 MeV = 106 eV 1 GeV = 109 eV 1 TeV = 1012 eV LEP = 209 GeV LHC = 14 TeV - + 1 Volt Egil Lillestøl, CERN & Univ. of Bergen

6. Einstein:E = Mc2 use units such that c =1 E (GeV or MeV) p (GeV/c or MeV/c) M (GeV/c2 or MeV/c2) Special Relativity: ( E2= (pc)2 + (M0c2)2 ) pc E Mproton = 0.931 GeV/c2 ≈ 1 GeV/c2 Melectron = 0.5 MeV/c2 ( Mtop = 170 GeV/c2 ) M0c2 proton diameter = length scale: 10-15 m = 1 fermi (femtometer) Egil Lillestøl, CERN & Univ. of Bergen

7. Creating New Matter with LEP fully described by the Standard Model : Egil Lillestøl, CERN & Univ. of Bergen

8. Ingredients of the Standard Model To explain all matter we needthree generationsof quarks We also havethree generationsof leptons. THE COMPLETE PICTURE: Quarks Leptons charges: 2/3 -1/3 0 -1 updown neelectron (e) charmstrange nmmuon (m) topbottomnttau (t) Two different sorts of Matter particles: -composite particles made up of quarks (called HADRONS) -non composite particles like electrons and neutrinos (LEPTONS) Egil Lillestøl, CERN & Univ. of Bergen

9. “Fundamental” Matter Particles heavier Charge +2/3 t u c quarks (q) s b d -1/3 nm ne nt 0 leptons e m t -1 Egil Lillestøl, CERN & Univ. of Bergen

10. Composite Matter Particles(hadrons) made out of quarks ( q ) and anti quarks ( q ) hadrons Baryons Mesons q q q q q Anti Baryons Hundreds of possible combinations orparticles q q q Egil Lillestøl, CERN & Univ. of Bergen

11. Forces of Nature name of field (wave)force carrier (particle) gravitational field graviton (?) electromagnetic field (a)g(photon) weak field Z0, W+, W- strong (color) field 8 gluons, g higgs field (*) h0, H0, H+, H-.. (*)Unifying the weak and the electromagnetic fields giving mass to the Z and the W’s - all other particles !!! (a) Electric and Magnetic Fields Unified by Maxwell (1864) Big Question: Can all Force Fields be unified ? (*) Egil Lillestøl, CERN & Univ. of Bergen

12. How the forces work the Strong Field (gluons)couple toQuarks the Weak field (W’s and Z)couple toLeptons the Electromagnetic fieldcouple toCharge (classical: F = qE) the Gravitational fieldcouple toMass (Newton: F = mg) the Higgs field couple to Mass ! ! ! In fact the Higgs field is responsible for the mass ! Can detailed studies of large number of Higgs Particles give us the explanation why we have three families of quarks and leptons, and why they have such enormous mass differences ?? LHC will tell us ! Egil Lillestøl, CERN & Univ. of Bergen

13. The Forces and Particles as Fields Newton and Gravity Faraday and Fields Forces as “Exchange” Particles Particles as Fields Forces and Particles as Quantum Fields Quantum Fields are part of Space itself ! Egil Lillestøl, CERN & Univ. of Bergen

14. How does a point in empty space know exactly the variety of particles it can produce and all their properties and their forces .... ??? Back to Heisenberg and Faraday: Particles and Forces are Quantum Fields filling every pointof “Empty” Space (or the “Vacuum”). The Fields materialize as Particles when Energy is fed into this Vacuum. Egil Lillestøl, CERN & Univ. of Bergen

15. Heisenberg’s Uncertainty Relation: (Dx)(Dp) ≈ h/(2p)or(Dt)(DE) ≈ h/(2p) (valid for the Fields as well as the Vacuum) h is Planck’s constant - a very small number, (6.6x10-34Js) x is position, p is momentum, t is time, and E is energy. (Dx) means uncertainty in position, etc Egil Lillestøl, CERN & Univ. of Bergen

16. In every Point of “Empty” Space there is full Information on all possible particles and all the fundamental forces ! Particles are produced when energy is fed into the Vacuum. Particles appear and disappear, but the “memory” remains Structuresare temporary, thePatternlasts for ever ! Egil Lillestøl, CERN & Univ. of Bergen

17. With LEP Blowing into the Vacuum producing the Z0 particle Collision Probability resonance curve resonance width (DE) Energy (e+ + e-) Z0-mass Egil Lillestøl, CERN & Univ. of Bergen

18. Z0 Decays : 3 jets e- e+ anti lepton e- e+ lepton Egil Lillestøl, CERN & Univ. of Bergen

19. 1989-1995: The4 LEP experiments collected and studied 17 million Z particles Z particles decays “democratically” into all possible quark-anti quark pairs (sometimes accompanied by one or more gluons) and all possible lepton-anti lepton pairs. Quarks and gluons seen as jets, and charged leptons as single tracks neutrino-anti neutrino pairs are NOT observed However, the number of different neutrino species can be found from the resonance width (or lifetime) of the Z particle Egil Lillestøl, CERN & Univ. of Bergen

20. Z0 resonance (line shape): E (or M) = 91.2 GeV DE (or DM) = 2.5 GeV Heisenberg: (DE) (Dt) = h/2p (h = 4x10-24 GeVs) (Dt) is the lifetime t and (DE) the resonance width giving t = 10-25 s corresponding to Only three light neutrino species, i.e. only three lepton generations, and three quark generations. Egil Lillestøl, CERN & Univ. of Bergen

21. Lifetime of Z0 like water in a leaking bucket: Z0 the more and bigger the holes - the shorter the lifetime a hole = a decay channel; Sizes of the holes can be calculated using the Standard Model Egil Lillestøl, CERN & Univ. of Bergen

22. How many “Holes” ? Quark pairs: charge number d-d, s-s, b-b 1/3 3 (x3) u-u, c-c 2/3 2 (x3) Lepton pairs: charge number e--e+, m-- m+, t-- t+, 1 3 n e- n e, n m- n m , ? 0 2+? Autumn 1989: Perfect match with 3 different neutrino species. Egil Lillestøl, CERN & Univ. of Bergen

23. LEP, the Top and the Higgs H g t t The “tune” of the bb-note has a nearly imperceptible “overtone” due to the presence of the higgs and the top quarks b b jets This overtone can be measured and calculated from the Standard Model with the higgs mass and the top mass as free parameters Predictions: top mass ≈ 175 GeV and higgs mass < 1000 GeV Egil Lillestøl, CERN & Univ. of Bergen

24. LEP and the Higgs Fermilab found the top with mass as predicted from LEP: Standard Model Higgs: MH < 1000 GeV Lightest Super Symmetric Higgs Mh < 200 GeV Best fit : Mh ≈ 100 GeV Within reach of LEP200 ! Egil Lillestøl, CERN & Univ. of Bergen

25. Is the Higgs Idea falsified ? Egil Lillestøl, CERN & Univ. of Bergen

26. Higgs Hunting with LEP (Total energy 206.6 GeV) (e- + e+) -----> (Z0 + H) -----> 4 jets two Higgs jets containing B-particles two Z jets H (115 GeV) e- e+ Z (91 GeV) 2.5 s effect for a Higgs Particle at 115 GeV Egil Lillestøl, CERN & Univ. of Bergen

27. ALEPH DELPHI Egil Lillestøl, CERN & Univ. of Bergen

28. B - Particles in DELPHI Egil Lillestøl, CERN & Univ. of Bergen

29. Questions for the LHC - Does Higgs Particles exist ? - Can all the Forces and Particles be unified ? (Super Symmetry) - Is Dark Matter made of Super Symmetric Particles ? - What happened to the Antimatter in the Universe ? - Did the Universe go through a Phase of Quark-Gluon Plasma ? - Are the Fundamental Particles two-dimensional Strings ? - Does the Universe have more than three Spatial Dimensions ? - Are there more Forces and Particles to be discovered ? - Accelerating Expansion of the Universe and Dark Matter - Could everything be just wrong ? The LHC Experiments will be very Exciting ! Egil Lillestøl, CERN & Univ. of Bergen