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Research Participation in Collider Based Particle Physics Stefan Spanier

Research Participation in Collider Based Particle Physics Stefan Spanier University of Tennessee, Knoxville. Experiments 111 years ago …. J.J. Thompson : Cathode rays are material constituents of atoms! bend in electric and magnetic field.

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Research Participation in Collider Based Particle Physics Stefan Spanier

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  1. Research Participation in Collider Based Particle Physics Stefan Spanier University of Tennessee, Knoxville

  2. Experiments 111 years ago … J.J. Thompson: Cathode rays are material constituents of atoms! bend in electric and magnetic field Nobel Prize 1906 G.P. Thompson: electrons have wave character Nobel Prize 1937 "Could anything at first sight seem more impractical than a body which is so small that its mass is an insignificant fraction of the mass of an atom of hydrogen?" Cathode Ray Tube  electron fundamental building block of matter

  3. Particle Accelerator as Microscope Length to be resolved R R  1/Particle Energy ~ keV 1eV = kinetic energy an electron gains in a electric field of 1 Volt > 10 MeV - > 100 MeV > 100 GeV 1.0 V - +

  4. The Standard Model _ _ _ _ _ _ _ _ _ Latest addition 1995 Tevatron at Fermilab Building Blocks particles anti-particles Charge + 2/3 - 1/3 Charge + 1/3 - 2/3 uctd s b d s bu c t e-m- t -nenm nt nenm nt e+m+ t+ Quarks -1 0 0 +1 Leptons mass Standard Model does not ‘predict’ any of the masses (parameters); How do masses come about?

  5. The Higgs Field How particles acquire masses … The Higgs particle mass generation

  6. Forces ~ 1015 GeV ? GUT scale coupling constants unify Higgs mechanism Electric MagneticPhotons m= 0 WeakW+,W -,Z0 m= 80, 90 GeV Strong Gluons m = 0 Gravity Gravitons ? Maxwell electroweak Planck energy~ 1019 GeV ~100 GeV Standard Model today’s accelerators just about … Seems unnatural ?

  7. GUT Force relative coupling Strong aS 1  0.12 Electromagnetic a 1/137  1/128 Weak aW 10-6 Gravity aG 10-39 1 strength least understood • Behavior of coupling constants supports idea, • but no common intersection? • introduce e.g. Supersymmety ? weak strong

  8. Supersymmetry ??? • Boson  Fermion symmetry • Spin ½ quarks  spin 0 squarks • Spin ½ leptons  spin 0 sleptons • Spin 1 gauge bosons spin ½ gauginos • Spin 0 Higgs spin ½ Higgsino •  Many particles to search for! What mass scale? • Supersymmetry is broken ...no scalar with mass of electron • Observation: • as missing mass (energy) if non-interacting • (lightest neutralino) • from decay into the lower mass standard • particles Simplest super-symmetric model has 105 new parameters …

  9. The Cosmic Connection • What is dark matter? • How are particle physics & cosmology connected? • What is dark energy? • Where did the anti-matter go? • (CP Violation) Stars and galaxies are only 0.1% Neutrinos are ~0.1–10% Electrons and protons are ~5% Dark Matter ~25% Dark Energy ~70%

  10. The LHC Machine and Experiments Proton-proton collisions at 14 TeV 27 km in circumference, 50-150m deep LHCf totem High Energyfactor 7 increase w.r.t. present accelerators High Intensity (# events/reaction/time)  factor 100 increase

  11. LHC Superconducting magnets: 1232 dipole magnets (bending) T=1.9 K (superfluid Helium) B – field > 8 Tesla ~500 quadrupole (focus)magnets LHC in LEP tunnel superconducting dipole magnet Energy stored/beam: 360 MJ Energy stored in magnets: 700GJ  Particle losses fatal !

  12. LHC – Beam 1 first + second turn

  13. A Higgs Event in the Compact Muon Solenoid m+ m- p p m+ m- Luminosity = 1034 cm-2s-1 = 107 mb-1Hz Interaction rate = 8 x 108 Hz Interactions/crossing = 25 (~1000 charged particles) Higgs event + ~25 minimum bias events Simulation H Z

  14. The CMS Detector Hadron Calorimeter Brass + scintillator Very forward calorimeter Vacuum chamber Central Tracker 66M Si-Pixel 10M Si-Strip Area: 220 m2 EM Calorimeter #80k PbWO4 crystals Superconducting coil 4Tesla, 20000A, -270oC Width: 22m Diameter: 15m Weight: 12,500 tons Muon chambers RPCs, DT(barrel), CSC(end) Iron return yoke

  15. The Pixel Detector z ~1 m 0.3 m • Barrel layers at radii = 4.3cm, 7.3cm and 10.2cm • Disks at +/-z = cm and cm • Pixel cell size = 100x150 µm2  ~1m2 of silicon /66 Million pixels • ~15k front-end chips and

  16. The Pixel Detector Principle B z After 1st year ~285mm MIP  29000 e- Primary signal electrons; Lorentz force smears charges Resolution: within square: ~25mm Charge sharing: 10 – 15 mm

  17. Pixel Diamond Detector – New Technology Pixel Luminosity Telescope prototype pixel readout at UTK

  18. Computing 15 Million Gigabytes of data each year (about 20 million CDs!) GRID Node at UTK 10 GBit/s connection; 246 processors + 50TByte storage

  19. The Commissioning / Operation

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