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PASI2006: Beyond the Standard Model in Cosmology, Astroparticle and Particle Physics

PASI2006: Beyond the Standard Model in Cosmology, Astroparticle and Particle Physics. Marleigh Sheaff University of Wisconsin. DPyC/SMF June 14-16, 2006.

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PASI2006: Beyond the Standard Model in Cosmology, Astroparticle and Particle Physics

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  1. PASI2006:Beyond the Standard Model inCosmology, Astroparticle and Particle Physics Marleigh Sheaff University of Wisconsin DPyC/SMF June 14-16, 2006

  2. This Pan-American Advanced Studies Institute will be held in conjunction with the Sixth Latin American Symposium on High Energy Physics (VI-Silafae) and the Twelfth Mexican School of Particles and Fields (XII-MSPF), October 23 - November 8, 2006. Marleigh Sheaff, Wisconsin

  3. PASI2006 ORGANIZING COMMITTEE • Marleigh Sheaff (University of Wisconsin, USA), chair • Marcela Carena (Fermilab, USA) • Daniel Chung (University of Wisconsin, USA) • Joao dos Anjos (CBPF, Brazil) • Miguel-Angel Perez (CINVESTAV, Mexico) Marleigh Sheaff, Wisconsin

  4. MOTIVATION • Present the evidence for physics beyond the Standard Model (SM). • Demonstrate that these three fields are not disjoint, but that results in each inform the others. • Showcase the very fine work going on in these fields in the Americas. • Bring together young physicists (Post Docs and Advanced Graduate Students) working in the three fields throughout the hemisphere. • Foster future collaborations that are both multidisciplinary and multinational. Marleigh Sheaff, Wisconsin

  5. PLANS • Start with eight Days of Lectures given by physicists who are not only experts in each area but also have excellent presentation skills • Discussion sessions following each day's lectures where students can ask questions. A number of Mexican physicists with expertise in these fields have agreed to help us with these sessions. • Joint program for PASI2006, VI-Silafae, and XII-MSPF for the next eight days. Mostly research seminars given in plenary sessions. Marleigh Sheaff, Wisconsin

  6. LECTURERS • Marcela Carena (Fermilab, USA) - Electroweak Symmetry Breaking, SM and Beyond, Higgs Physics at the LHC/ILC • Daniel Chung (U. of Wisconsin, USA) - Particle Cosmology Fundamentals • Daniel de Florian (Buenos Aires U., Argentina) - QCD, a Background to New Physics • Andre de Gouvea (Northwestern U., USA) - Neutrino Physics, Phenomenology • Scott Dodelson (Fermilab and U. of Chicago, USA) Cosmology • Joao dos Anjos (CBPF, Brazil) - Neutrino Physics, Experiment • Boris Kayser (Fermilab, USA) - Neutrino Physics, Theory • Alex Kusenko (UCLA, USA) - cosmology/astroparticle physics • Mattias Neubert (Cornell U., USA) - B/K Physics • Abdel Perez-Lorenzana (CINVESTAV, Mexico) - Extra Dimensions at LHC/ILC • Carlos Wagner (Argonne Lab and U. of Chicago, USA) - SUSY, including LHC/ILC Physics Marleigh Sheaff, Wisconsin

  7. DISCUSSION LEADERS • Guilermo Contreras (CINVESTAV, U. Merida) • Jens Erler (IF-UNAM) • Ricardo Lopez (CINVESTAV, Mexico) • Omar Miranda (CINVESTAV, Mexico) • Eduardo Ponton (Columbia U., USA) • Sarira Sahu (ICN-UNAM) • Alberto Sanchez (CINVESTAV, Mexico) Marleigh Sheaff, Wisconsin

  8. What is the SM? • Gauge theory. • Describes strong, electromagnetic, and weak interactions. • SU(3) x SU(2) x U(1) • Explains the results of all experiments to date. (Well, almost!) • Basic theory is massless. Marleigh Sheaff, Wisconsin

  9. What does the SM tell us? • Basic Building Blocks found in ordinary matter or in all particles produced in experiments to date are the 3 families of quarks and leptons and their antiparticles. • To each quark and lepton there corresponds an antiquark or antilepton for which all additive quantum numbers are of the opposite sign. These are not found in ordinary matter but can be produced in experiments. • Forces between the quarks and leptons can be understood as the exchange of force carriers (gauge bosons) for three of the four known forces (Weak, EM, and Strong). Marleigh Sheaff, Wisconsin

  10. What does the SM NOT tell us? • What about the fourth known force, gravity? Can we incorporate it into the theory? Can we realize Einstein's dream of a Grand Unified Theory? • The gravitational force is much weaker than the other three. Energy scale is very high. • MPL (ch/GN)1/2 ~1019 GeV. Marleigh Sheaff, Wisconsin

  11. Electroweak Unification Data from the HERA ep Collider • Two of the four known forces are seen to be unified. • Scale is ~(300 GeV)2. • The masses of the gauge bosons are very different. The carriers of the weak force (W,Z) have masses ~100 GeV. The carrier of the em force, the photon, is massless. • Range of weak force is very short <10-17 cm. Marleigh Sheaff, Wisconsin

  12. What does the SM NOT tell us? • Why are the masses of the gauge bosons so different? • Why are the masses of the various quarks and leptons so different, spanning many orders of magnitude? • Why are there three families of quarks and leptons? Ordinary matter is made up only of u and d quarks and electrons. Marleigh Sheaff, Wisconsin

  13. HIGGS Field • Breaks electroweak symmetry by spontaneous symmetry breaking giving masses to the W and Z. • Also gives masses to the quarks and leptons (slows them down so they do not travel at c). • Must permeate all space in order to do this. • Its couplings are proportional to mass. • Simplest interpretation, the SM Higgs, is a single scalar boson, but this is only one of the many possibilities proposed. Marleigh Sheaff, Wisconsin

  14. Properties of SM Higgs • W Boson Scattering grows with energy A ~ GFE2 and violates unitarity at 1.8 TeV • Unitarity can be restored by adding a single spin 0 particle (scalar boson) with couplings that are precisely those of the SM Higgs Marleigh Sheaff, Wisconsin

  15. Expected Mass of the Higgs LEPEWWG fit at the Zo pole from electroweak precision data and SM theory • mH = 126 +73/-48 GeV • mH  260 GeV (95% c.l.) Marleigh Sheaff, Wisconsin

  16. SM Higgs at the LHC • Finding the Higgs is the primary goal of the two main experiments being built for the the Large Hadron Collider at CERN, CMS and ATLAS. • The LHC is expected to come on line and to be commissioned sometime in Fall 2007. Marleigh Sheaff, Wisconsin

  17. From Joe Lykken at Pheno 06 - Marleigh Sheaff, Wisconsin

  18. Compact Muon Solenoid Marleigh Sheaff, Wisconsin

  19. SM Higgs in CMS Marleigh Sheaff, Wisconsin

  20. SM Higgsin ATLAS Marleigh Sheaff, Wisconsin

  21. Is discovery really the Higgs? • Is its coupling proportional to mass? • How about its spin and parity - is it JP = 0+? • Does it condense in the universe? • To answer these detailed questions it is felt that we will need both the LHC and the ILC, the International Linear Collider. Marleigh Sheaff, Wisconsin

  22. The International Linear Collider • e+ e- Collider with 500 GeV center-of-mass energy. • To be upgraded to 1 TeV later on. • Must be linear collider at this energy to avoid huge losses to synchrotron radiation. • Beams accelerated along path  15 km. • Beams focused down to a few nanometers in the collision region to get the luminosity required for the measurements. L ~ 1034 cm-2 sec-1. • Need for high precision places stringent requirements on the detectors. Marleigh Sheaff, Wisconsin

  23. The International Linear Collider Marleigh Sheaff, Wisconsin

  24. Measure properties of the Higgs • Study SM Higgs (assuming discovery at the LHC). • Precise measurement of branching fractions proves that Higgs is responsible for masses of SM particles, i.e., couplings  mass. • Bands show SM theoretical errors. Error bars show expected experimental errors for 500fb-1 at 350 GeV. Marleigh Sheaff, Wisconsin

  25. The Hierarchy Problem • Mass of Higgs at the scale where electroweak symmetry is broken must be of order MW to restore unitarity through cancellation of diagrams. • This is many orders of magnitude below the mass of the GUT scale where the strong interaction becomes unified with the electroweak, MGUT ~ 1015-1016. Squared mass of Higgs shows a quadratic divergence as we run it up to this scale. • The scale of the gravitational interaction is even higher, MPL ~ 1019. Marleigh Sheaff, Wisconsin

  26. Supersymmetry (SUSY) • Each SM fermion has a superpartner that is a boson and each SM boson has a superpartner that is a fermion. (Boson-Fermion Symmetry) • Superpartners have the same quantum numbers and couplings as their partner SM particles. • Contributions to loop diagrams for radiative corrections to the Higgs mass are of opposite sign and cancel removing the quadratic divergence as we run the mass up to GUT scale. • Naturalness requires that |m2B -m2f| ≤ O(1 TeV2). • With SUSY, couplings for SM forces meet at common energy scale ~1015-1016 within current experimental bounds. Marleigh Sheaff, Wisconsin

  27. History Repeats Itself • Electron is pointlike, at least down to ~10-17 cm. • Since like charges repel, how can electron's charge be confined to such a small volume? • Energy required to do this is ∆mec2 ≈ e2/re and e2/re ≈ GeV(10-17cm/re). • ∆mec2 > mec2 for re smaller than 10-13. • Electromagnetism doesn't work below re of 10-13. Marleigh Sheaff, Wisconsin

  28. Solution - double the number of particles by adding antiparticles • Vacuum polarization - electron continuously emits and reabsorbs virtual photons, which produce e+ e- pairs, thus shielding electric charge. • ∆me ≈ me(/4)log(mere). • Only 10% of me even at Planck scale rPL ~ 10-33. Marleigh Sheaff, Wisconsin

  29. Higgs is Pointlike • Higgs self-coupling causes similar problem. • Energy required to contain it in its pointlike size is ∆mH2c4 ~ (hc/rH)2. • Weak force breaks down at order 1 TeV. Marleigh Sheaff, Wisconsin

  30. Add superpartners which doubles number of particles • Vacuum bubbles of superpartners cancel energy due to Higgs self-coupling. • ∆mH2~(/4)m2SUSYlog(mHrH). • Takes us to GUT scale, i.e., shorter distances. Marleigh Sheaff, Wisconsin

  31. SUSY must be a broken symmetry • If SUSY were an exact symmetry, superpartners would have exactly the same mass as their SM counterpart. • No superpartner has yet been discovered, although searches have been carried out up to the highest masses achievable in present experiments. • We expect that, if SUSY particles do exist, the lowest mass states are likely to be discovered at the LHC. Marleigh Sheaff, Wisconsin

  32. R-Parity • R-parity was introduced to forbid couplings that violate baryon number or lepton number conservation, which allow a proton decay rate well above that allowed by experiment. • R = (-1)2j+3B+L, where j=spin, B=baryon number, and L=lepton number. R=+1 for SM particles and -1 for superparticles. • Superparticles must be produced in pairs. • The lowest mass superpartner will be stable since it can't decay to SM particles,. Marleigh Sheaff, Wisconsin

  33. The Cosmology Connection • Universe started with the (hot) Big Bang some 15 billion years ago. • BB was followed by a period of rapid expansion called inflation. • Expansion has continued since then at a slower rate with a continual decrease in temperature and stretching of the scale. • Hubble constant, H=72 km sec-1 Mpc-1. Velocity at which distant objects recede from us is proportional to their distance. We can measure by their red shift. • Accelerator energies are now getting high enough to reach the energy present in the very early universe. Energy related to temperature through Boltzmann's constant, kB. Marleigh Sheaff, Wisconsin

  34. History of the Universe • LHC Energy is above the energy of the universe at the time when EW symmetry was broken. • Takes us closer to the Big Bang than 10-11 sec! • Allows us to explore the scale where we expect to see SUSY particles. Marleigh Sheaff, Wisconsin

  35. SUSY at the LHC and ILCGaugino Mass Unification • LHC is expected to discover SUSY particles that couple through the strong interaction squarks and gluinos and their decay products. • ILC is expected to measure all the SUSY particle masses and couplings precisely. • 1 TeV energy, 1000 fb-1, and high beam polarization needed to fully characterize SUSY and to discover the forces that break SUSY. Marleigh Sheaff, Wisconsin

  36. What does the SM NOT tell us? • What everything else is. • Cosmological observations indicate that SM particles comprise only ~ 5% of the energy budget of the universe. • Since cosmological observations and particle physics must agree, new physics (i.e., physics beyond the SM) is needed to explain this. Marleigh Sheaff, Wisconsin

  37. Energy Budget of the Universe • Stars and Galaxies ~ 0.5% • Neutrinos ~ 0.1-1.5% • Rest of Ordinary Matter (protons, neutrons,electrons) 4.4% • Antimatter 0% • Dark Matter 23% • Dark Energy 73% Marleigh Sheaff, Wisconsin

  38. Evidence for Dark Matter Rotational Curves of Galaxies and Galactic Clusters • Expect vc ~ r -1/2 outside luminous region • Find vc a constant • Inconsistency resolved by postulating Dark Matter. • Confirmed by measurements of gravitational lensing NGC 2403 Marleigh Sheaff, Wisconsin

  39. Distribution of Dark Matter Marleigh Sheaff, Wisconsin

  40. Could the LSP explain Dark Matter? • Dark Matter feels gravitational interaction since it clumps in the vicinity of luminous (SM) matter. • The properties of the least massive superpartner (LSP) make it a likely candidate to be Dark Matter. Typically it's a mixture of electoweak gauginos and Higgsinos called the neutralino, . • LSP mass expected to be ~100 Gev - 1 TeV. • Would interact only weakly (WIMP). • LSP would have relic abundance of the correct size to match the Dark Matter abundance. Marleigh Sheaff, Wisconsin

  41. The Neutralino as Dark Matter Jonathan Feng - Frontiers in Contemporary Physics 2005 Marleigh Sheaff, Wisconsin

  42. Evidence for Dark Energy • Supernovae Ia are Standard Candles - luminosity scales with the inverse of the distance squared. • Recession velocity measured by red shift depends on distance of SN from us. • SN with largest red shift have lower luminosity than expected indicating that the expansion of the universe is accelerating. SDSS II Marleigh Sheaff, Wisconsin

  43. Evidence for Dark Energy • Dark Energy is equivalent to Einstein's cosmological constant, . • Fits to WMAP data show it is needed to describe temperature fluctuations observed in CMB. • Temperature fluctuations are the result of perturbations that occurred during Inflation. Marleigh Sheaff, Wisconsin

  44. What does the SM NOT tell us? • Why there is a complete asymmetry between matter and antimatter in the universe. Where did all the antimatter go? • The relatively small CP violation seen in the quark sector does not appear to be large enough to produce this. • The discovery of large mixing angles in the lepton sector indicate we are seeing new physics. More experiments are needed to elucidate it. Marleigh Sheaff, Wisconsin

  45. Other Evidence for Physics Beyond the SM - The Neutrino Revolution • Over the past 8 years, neutrino experiments have become precise (and clever) enough to discover that neutrinos oscillate. • This means that neutrinos have mass. • SM neutrinos are only left-handed. This can't be if they have mass. OK if neutrinos are their own antiparticles. • SM neutrinos conserve lepton number, but not if they are their own antiparticles. Marleigh Sheaff, Wisconsin

  46. Properties of Neutrinos e • Neutrinos have mass and therefore no longer travel at c. • If we boost ourselves to near c and look back, the neutrino will appear to be right-handed. • Anti-neutrinos are right-handed, so if neutrinos are their own anti-particles this can be accommodated in the SM. Marleigh Sheaff, Wisconsin

  47. Solar Neutrino Problem finally resolved after 40 years • Ray Davis was a chemist at Brookhaven National Laboratory. • He placed a very large tank of cleaning fluid deep in the Homestake mine to detect electron neutrinos from the Sun using the reaction e+Cl37e-+Ar37. • The number of e's detected with energy above threshold for this reaction, 814 keV, was only ~1/3 of the flux expected in the Standard Solar Model of Bahcall. • Ray Davis received the 2002 Nobel Prize for this landmark measurement. Marleigh Sheaff, Wisconsin

  48. (-) (-) For   , P(   ) = sin2 2 sin2 (m2 ) . For no flavor change P(   ) = 1 - sin2 2 sin2 (m2 ) . L L 4E 4E Appearance (-) (-) Disappearance Neutrino Oscillations? When only two species of neutrino contribute - m2 = (m2 - m2)2. Gives difference but not the sign. Marleigh Sheaff, Wisconsin

  49. FLUX of  +  FLUX of e Missing Neutrinos Found by SNO! • e+Dp+p+e- (CC - e only) x+Dp+n+x (NC - all 3) • CC/NC=0.306±0.026±0.024 • Full flux of 8B e predicted in SSM seen, 5x106 cm-2s-1. • Consistent with MSW effect (matter effects in the Sun) and neutrino oscillations. • Adding KamLAND data makes oscillation parameters more precise. Data from D2O with NaCL added Marleigh Sheaff, Wisconsin

  50. Mikheyev-Smirnov-Wolfenstein Effect • Neutrinos produced in the sun are all e. SNO 8B detection threshold is 5MeV. • e survival probability is just e fraction of 2 (LMA solution). • Neutrinos do not oscillate as they travel from the Sun to the Earth, since they have gone through an adiabatic matter resonance and leave the Sun in the mass eigenstate 2. Marleigh Sheaff, Wisconsin

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