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What’s Hot in High Energy Particle Physics

What’s Hot in High Energy Particle Physics. Study of the fundamental constituents & interactions of matter. What is the universe made of and by what rules do they play?. Masses on the subatomic scale. electron proton iron nucleus. 9.1093 10 -31 kg. 0.511 MeV. 938.28 MeV.

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What’s Hot in High Energy Particle Physics

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  1. What’s Hot in High Energy Particle Physics Study of the fundamental constituents & interactions of matter. What is the universe made of and by what rules do they play?

  2. Masses on the subatomic scale electron proton iron nucleus 9.109310-31 kg 0.511 MeV 938.28 MeV 1.672110-27 kg 52153.77 MeV 9.299010-26 kg

  3. Henri Becquerel(1852-1908) 1903 Nobel Prize discovery of natural radioactivity Wrapped photographic plate showed distinct silhouettes of uranium salt samples stored atop it. • 1896 While studying fluorescent & phosphorescent materials, Becquerel finds • potassium-uranyl sulfate spontaneously emits radiation that can penetrate •  thick opaque black paper •  aluminum plates •  copper plates

  4. 1930splates coated with thick photographic emulsions (gelatins carrying silver bromide crystals) carried up mountains or in balloons clearly trace cosmic ray tracks through their depth when developed fast charged particles leave a trails of Aggrains1/1000 mm (1/25000 in) diameter

  5. Nature 163, 82 (1949) C.F.Powell, P.H. Fowler, D.H.Perkins Nature 159, 694 (1947)

  6. e   HTTP://PDG.LBL.GOV Particle Data Group Created: 10/24/2002

  7.  0    150 mesons!! HTTP://PDG.LBL.GOV Particle Data Group Created: 06/18/2002

  8. n p HTTP://PDG.LBL.GOV Particle Data Group Created: 06/18/2002

  9. 121 baryons!!

  10. c d u p0 p+ s p+ n p QuarkCharge up +2/3e down -1/3e charm +2/3e strange -1/3e

  11. StateQuark contentMassSpin p uud 938.272MeV 1/2 n udd 939.565MeV 1/2  uds 1115.683MeV 1/2 + uus 1189.37 MeV 1/2  0 uds 1192.632 MeV 1/2  - dds 1197.449 MeV 1/2  0 uss 1314.9 MeV 1/2  - dss 1321.32 MeV 1/2 ++ uuu1230. MeV 3/2 + uud 1231 MeV 3/2  0 udd 1233 MeV 3/2  -ddd1234 MeV 3/2 *+ uus 1382.8 MeV 3/2 *0 uds 1383.7 MeV 3/2 *- dds 1387.2 MeV 3/2 *0 uss 1531.80 MeV 3/2 *- dss 1535.0 MeV 3/2  - sss1672.45 MeV 3/2 Baryon States can all be explained as combinations of 3 fundamental quarks Meson States can all be explained 2 quarks combinations + ud 139.57 MeV + ud 139.57MeV 0 uu 134.98MeV 0 dd 546.30 MeV

  12. E c B How do 2 (mutually repulsive) electrons sense one another’s presence? To be charged: means the particle is capable of emitting and absorbing photons  e  e

  13. electrostatic repulsion e- e-  e- e- nuclear binding u d g u d me e- W - m- “weak” decays

  14. The Detector in various stages of assembly

  15. 38 foreign institutions 3 national labs:BNL, LBL,FNAL 36U.S.university HEP groups

  16. The CMS Detector CERN, Geneva, Switzerland

  17. The Cosmic Questions Why are there so many particles? Are there yet any new laws to discover? What is this Dark Matter? What are massive neutrinos telling us about the world? What is the origin of particle masses? Are there dimensions beyond 4-dimensional space-time? Do the fundamental forces unify? How did the universe come to be? Where did all the antimatter go?

  18. Astronomers say that most of the matter in the Universe is invisible Dark Matter Supersymmetric particles ? Something we are actively looking for!

  19. mproton= 1836  melectron p+ p- e- e+

  20. SUPERSYMMETRY Particle Name Symbol Spartner Name Symbol gluon g gluino g charged Higgs H+ chargino W1,2 charged weak boson light Higgs h neutralino Z1,2,3,4 heavy Higgs Hpseudoscalar Higgs Aneutral weak boson Z photon  quark q squark qR,L lepton l slepton lR,L ~ ~ ~ ~ ~

  21. Charginos and Neutralinos ~ ~ Production of 1 02 will lead to trileptonfinal stateswithET perhaps thecleanestsignature of supersymmetry. ~ 01   q q ~ 1 02 ~~ ~ ~ pp  q, g  102  + ET W* W* Z* ~   ~ 01 ~ 01 ~ ~ q q 1 02 ~ 01 ~ ~ *  ~   02 ~ 1  q*  ~

  22. Squarks and Gluinoscan decay directly into the LSP (01)   01   01  q  g  q q q q or cascade down to the LSP q q  q q  g q  q   1  q  g q  02  q  q q q   01   01 q q    So that the dominant signature forppqq, qg, gg + Xisjets+ET

  23. Supersymmetry Searches at LHC LHC reach in supersymmetric parameter space `Typical’ supersymmetric Event at the LHC Can cover most possibilities for astrophysical dark matter

  24. String Theory • Candidate theory of quantum gravity • Point-like particles → extended objects • lengths of “string” • Requiresextra dimensions

  25. R Flat dimension

  26. Picking a fundamental particle for common reference If photons traverse our 3-dim space but gravitons spread out over 3+n… for r >> R

  27. So far NO distribution of measured particle characteristics or behavior show ANY effect attributable to extra dimensions.

  28. Hints on the Higgs Mass Best-fit value:mH = 91+45–32 GeV 95% confidence-level upper limit: mH < 219 GeV

  29. Best-fit value:mH = 91+45–32 GeV 95% confidence-level upper limit:mH < 219 GeV current limit fixed by direct searches mH > 114 GeV I’sexpected reach(before CERN’s LHC turns on) ~120 GeV

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