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Physics Beyond the SM

Physics Beyond the SM. Wim de Boer, KIT. Outline. Lecture I ( SM+Cosmology ) What are the essentials of a Grand Unified Theory (GUT)? Which predictions follow from a GUT? Dark energy and dark matter Inflation and accelerated expansion of the universe

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Physics Beyond the SM

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  1. PhysicsBeyondthe SM Wim de Boer, KIT

  2. Outline • Lecture I (SM+Cosmology) • What are the essentials of a Grand Unified Theory (GUT)? • Which predictions follow from a GUT? • Dark energy and dark matter • Inflation and accelerated expansion of the universe • Lecture II (Supersymmetry) • Gauge and Yukawa coupling unification in SUSY • Prediction of electroweak symmetry breaking in SUSY • Prediction of the top mass in SUSY • Prediction of the Higgs mass in SUSY • Prediction of Relic density • Prospects for discovering SUSY Details in Manylsummerschoollectureson Supersymmetry in: http://www-ekp.physik.uni-karlsruhe.de/~deboer/html/Lehre/Susy/ W. de Boer, hep-ph/9402266, arXiv:1309.0721

  3. Fundamental Questions Cosmology Particle Physics • Why more matter than antimatter ? • What is dark matter? • How did galaxies form? • What is the origin of mass? • Why hydrogen atom neutral? • Why forces so different strength? Magic solution: SUPERSYMMETRIC GRAND UNIFIED THEORIES

  4. What is SUSY? Supersymmetry is a Boson-Fermion symmetry, which allows to unify all forces of nature (including gravity). SUSY canexist in nature ONLY, ifthereareasmany bosonsasfermions Doubling the particle spectrum (Waw, Eldorado for experimental particlephysicists) In modern theories particles are excitations of strings in 10-dimensional space (String theory)

  5. SUSY Shadow World One half is observed! One half is NOT observed!

  6. Particle spectrum in SUPERSYMMETRY

  7. Gauge coupling unification

  8. - - - - - - - - + + + + + + + + - Grand Unified Theories How can one unify the different forces? Answer: forces are in principle equally strong. Difference at low energies by quantum fluctuations! Greetings from Heisenberg Field around a coloured quark reduced by screening of quark pairs, BUT enhanced by gluon pairs (gluons have self-interaction in contrast to photons) Antiscreening dominates-> field at large distance larger than at short distance-> Coupling at low energy larger than at high energy. Field around an electric charge reduced by screening from electron-positron and other fermion-antifermion pairs (Vacuumpolarisation)

  9. Why are gauge couplings running? Answer: couplings  charges, but bare charges shielded by quantum fluctuations Electric charge in electron Spatiolcharge distribution of electromagnetic charges (reduced at large distance because of screening by vacuum polarization)   Colour charge in proton In strong interactions: vacuum fluctuations from gluons->qq AND gluons->gg Latter dominates, thus enhancing colour charge at large distances (antiscreening)  Because of opposite screening effects, opposite running of electromagnetic and strong interactions! At higher energies also SUSY particles in vacuum -> change of running!

  10. Evidence for Running coupling constants Elektromagn. interaction increases at high energies. Finestructur constant 1/137 becomes 1/128 at LEP! Strong interaction decreases at high energies (= small distances)-> Asymptotic freedom of quarks in p,n.

  11. Gauge unification perfect for SUSY scales 1-4 TeV SM SUSY Update from Amaldi, dB, Fürstenau, PLB 260 1991

  12. mSUGRA: need to solve 28 coupled differential RGEs (From W. de Boer, Review, hep-ph/9402266)

  13. We like elegant solutions

  14. On the 1000+ citation list..

  15. Predictionof Higgsmechanism in SUSY

  16. TheHiggsMechanism Particlesslowed down by interactionswithHiggsbosons

  17. What is spontaneous symmetry breaking? Higgsfeld:  = 0 e i When phases arbitrary, thenaveraged vacuum-expectation-value< |> =0 When phases all equal, then v.e.v≠ 0! Spontaneous means if order parameter falls below a certain value, like temperature in superconductivityorfreezingofwater

  18. Higgs Mechanism

  19. SM SUSY Higgs Bosons 4=2+2=3+1 one degree of freedom left = 1 Higgs boson MSSM 8=4+4=3+5 = 5 Higgs bosons

  20. The Higgs Potential Solution Minimization At the GUT scale No SSB in SUSY theory !

  21. Masstermschangedbyradiativecorrection Common masses at GUT scale: m0for Scalars m1/2for S=1/2 Gauginos m1,m2for Higgs bosons m2 gets radiative corrections from top mass. Top mass has to be heavy enough to get m2 < 0 when running from GUT to EW scale: 140<mtop<190 GeV Lightest Supersymmetric Particle (LSP) =Neutralino

  22. Higgs-Boson-Masses in SUSY CP-odd neutral Higgs A CP-even charged Higgses H CP-even neutral Higgses h,H Excluded, but rad. corr. increase mass Mh 125 GeVfürmstop  few TeV(below 1 TeV in NMSSM)

  23. Higgs mass in MSSM and NMSSM WDB et al., arXiv:1308.1333 MSSM Higgs mass in MSSM 125 GeV for mstop  3 TeV NMSSM: mixing with singlet increases Higgs mass at TREE level for small tan and large  NO MULTI-TEV stops needed

  24. The giganticdarkenergyproblem Problem: VacuumenergyofHiggsfieldestimatedtobe 55-120 ordersofmagnitude larger than observeddensity. WHY IS THE UNIVERSE SO EMPTY??? Did EWSB provideanother burstofinflation, thusdiluting energydensityofHiggsfield?? Oristhiswayofestimatingenergydensitywrong? (Brodsky et al.) V(=0) = -mH2mW2/2g2 = O(108 GeV4) = 1026 g/cm3 1 GeV4=(GeV/c2 )(GeV3/(ħc)3) = 10-24 g 1042 cm-3 = 1018 g/cm3 Averagedensity in universe: crit= 2 x 10-29 g/cm3

  25. Summary on Higgs • The Higgs boson is a new class, at a pivot • point of energy, intensity, cosmic frontiers. • “Naturally speaking”: • It should not be a lonely particle; has an “interactive friend circle”: • and partners … • If we do not see them at the LHC, they may reveal their existence from Higgs coupling deviations from the SM values at a few percentage level. • An exciting journey ahead of us!

  26. Yukawa Unification

  27. Yukawa Coupling Unification

  28. Approximatetriple Yukawa couplingunificationfor large tan • SUSY not onlyprovides UNIFICATION ofgaugecouplings, but also unificationof Yukawa couplings. • Sincequarksandleptons in same multiplet in GUTs • Quark andleptonmassesrelated. • Indeed,correct b/massratio (in same multiplet in SU(5) • and in SO(10) also top mass (whichgetsmassfrom different Higgsdoublet) cangetcorrectmasswith same Yukawa coupling! for large tanratioof • vev‘sofHiggs d Yukawa coupling Unification wdb et al, PLB 2001, arXiv:hep-ph/0106311

  29. Relic Density

  30. Expansion rate of universe determines WIMP annihilation cross section T>>M: f+f->M+M; M+M->f+f T<M: M+M->f+f T=M/22: M decoupled, stable density (wennAnnihilationrateExpansionrate,i.e. =<v>n(xfr)  H(xfr) !) Thermal equilibrium abundance Actual abundance Comoving number density WMAP -> h2=0.1130.009 -> <v>=2.10-26 cm3/s DM increases in Galaxies: 1 WIMP/coffee cup 105 <ρ>. DMA (ρ2) restarts again.. Annihilation into lighter particles, like quarks and leptons -> 0’s -> Gammas! T=M/22 Only assumption in this analysis: WIMP = THERMAL RELIC! x=m/T Jungmann,Kamionkowski, Griest, PR 1995

  31. t t bb Annihilation cross sectionsin m0-m1/2 plane (μ > 0, A0=0) Annihilation cross sections can be calculated,if masses are known (couplings as in SM). Assume not only gauge coupling unification at GUT scale, but also mass unification, i.e. all Spin 0 (spin 1/2) particles have masses m0 (m1/2). For WMAP x-section of <v>2.10-26 cm3/s one needs relatively small LSP masses 10-24  WW mSUGRA: common masses m0 and m1/2 for spin 0 and spin ½ particles

  32. R-Parity

  33. R-Parity prevents proton decay R-Parity requires TWO SUSÝ particles at each vertex. Therefore proton decay forbidden, but DM annihilation allowed leading to indirect detection by observing stable annihilation products and also elastic scattering allowed leading to possible direct detection. No decay of lightest SUSY particle (LSP)in normal particles allowed->LSP is stable and perfect candidate for DM.

  34. WhatelseisknownaboutDM crosssections? x DM DM DM DM DM DM x II I III • < 10-8 pb DM from • tag by Z ormonojet • (Z-tag lessbg, more sens.) • ≈ 10pbfrom • relicdensityW • (assuming thermal relic) • < 10-8 pbfrom • direct DM searches p p p p p,b In blob: only Z orHiggsparticlestoexplain neutral andweakinteractions But 9 ordersofmagnitudebetween I and II mosteasilyexplainedby Higgsexchange, sinceHiggscouplesonlyweaklyto light quarks Need DM as SM singlet, so littlecouplingto Z, sinceelse I wouldbe large Higgs Portal models: in III Higgsisportalbetweenvisibleandinvis. sector! (seeKanemura, Matsumoto,Nabeshima, Okada arXiv:1005.5651) SUSY withsingletHiggs: NMSSM (DM = „singlino-like“) Or DM bino-likeneutralino, whichdoes not coupleto Z either (MSSM) p,b

  35. Higgs invisible Width in Higgs Portal Models Search for: pp-> ZH->2l+Emiss pp-> ZH->2b+Emiss pp-> qqH->2q+Emiss 1402.3244 1404.1344 Upperlimit on invisible width: 2-3 MeVfor DM mass < MH/2

  36. Status of NMSSM • NMSSM 1) solves m-problem • (mparameter =vev of singlet, so naturally small) 2) predicts naturally Mh>MZ, • so no need for radiative corrections from multi-TeV stop masses. Many papers since discovery of 125 GeV Higgs, see e.g. • arXiv:1408.1120, arXiv:1407:4134, arXiv:1407.0955, arXiv:1406.7221, • arXiv:1406.6372, arXiv:1405.6647, arXiv:1405.5330, arXiv:1405.3321, arXiv:1405.1152, arXiv:1404.1053, arXiv:1403.1561, arXiv:1402.3522, arXiv:1401.1878, arXiv:1312.4788, arXiv:1311.7260, arXiv:1310.8129, arXiv:1310.4518, arXiv:1309.4939, arXiv:1309.1665, arXiv:1405.5330, arXiv:1308.4447, arXiv:1308.4447, arXiv:1308.1333, arXiv:1307.7601, arXiv:1307.0851, arXiv:1306.5541, arXiv:1306.3926, arXiv:1306.3646,arXiv:1306.0279, arXiv:1305.3214, arXiv:1305.0591, arXiv:1305.0166, arXiv:1304.5437, arXiv:1304.3670, arXiv:1304.3182, arXiv:1303.6465, arXiv:1303.2113, arXiv:1303.1900, arXiv:1301.7584, arXiv:1301.6437, arXiv:1301.1325,arXiv:1301.0453, arXiv:1212.5243, arXiv:1211.5074, arXiv:1211.1693, arXiv:1211.0875, arXiv:1209.5984, arXiv:1209.2115, arXiv:1208.2555, arXiv:1207.1545, arXiv:1206.6806, arXiv:1206.1470, arXiv:1205.2486, arXiv:1205.1683, arXiv:1203.5048, arXiv:1203.3446, arXiv:1202.5821, arXiv:1201.2671, arXiv:1201.0982, arXiv:1112.3548, arXiv:1111.4952, arXiv:1109.1735, arXiv:1108.0595, arXiv:1106.1599, arXiv:1105.4191, arXiv:1104.1754, arXiv:1101.1137,

  37. Higgs mass in MSSM and NMSSM WDB et al., arXiv:1308.1333 MSSM Higgs mass in MSSM 125 GeV for mstop  3 TeV NMSSM: mixing with singlet increases Higgs mass at TREE level for small tan and large  NO MULTI-TEV stops needed

  38. Branching ratios in NMSSM may differ from SM • Total width of 125 GeV Higgs tot may be reduced somewhat by mixing with singlet (singlet component does not couple to SM particles) and new decay modes, like H3H2+H1 • Mixing depends on unknown masses, so deviations not precisely known. Expect O(<10%) deviations. • Higgs with largest singlet component usually lightest one. Since it has small couplings to SM particles, it is NOT excluded by LEP limit. Dark Matter candidate is Singlino instead of BINO in MSSM. Singlino mass typically 30-100 GeV.

  39. Lightest singlet Higgs at LEP? NMSSM consistent with H1=98 GeV, H2=126 GeV, motivated by 2 excess observed at LEP at 98 GeV with signal strength well below SM. (Belanger, Ellwanger, Gunion, Yian, Kraml, Schwarz,arXiv:1210.1976) H1 hard to discover at LHC, may be in decay mode H3H2+H1 , see e.g. Kang, Li, Li, Shu, arxiv:1301.0453 114.3 Aleph, Delphi, L3, Opal Phys. Lett. B565 (2003) 61 2

  40. Expectedcouplingprecision (SM)

  41. Time evolution of Universe Cosmologybadlyneeds evidenceforsymmetrybreaking via scalarfield. Idea: High vacuumdensityof such a scalarfield in earlyuniverse duringbreakingof GUT wouldprovide a burstof inflationby „repulsive“ gravity. Otherwisenoexplanation whytheuniversehas matter, is flat andisisotropic. Discovery ofHiggs fieldasoriginofewsbimportant

  42. IstheHiggs Field the „Origin ofMass“? Answer: YesandNo. Energyormass in Universehaslittleto do withtheHiggsfield. Higgs fieldgivesonlymasstoelementaryparticles. Mass in universe: Atoms: mostofmassfrombindingenergyofquarks in nuclei, providedbyenergy in colourfield, not Higgs field. (bindingenergy  potential energyofquarks  kinetic energieofquarks, ca. 1 GeV, but massofu,dquarksbelow1 MeV! 2) Massofdark matter: unknown, but in Supersymmetrybybreakingofthissymmetry, not bybreakingofelectroweaksymmetry.

  43. Summary on SUSY Higgs mass IS below 130 GeV, as PREDICTED by SUSY! • SUSY provides UNIFICATION ofgaugecouplings • SUSY provides UNIFICATION of Yukawa couplings • SUSY predicted EWSB for 140 < Mtop < 190 GeV • SUSY provides WIMP Miracle: • annihilation x-section -> correctrelicdensity • SUSY solveshierarchyproblem • SUSY providesconnectionwithgravity

  44. Whereis SUSY? Exp. for 3000/fb at 14 TeV3000 GeV Gluino sensitivity Now: 1200 GeV 1308.1333

  45. Radiativecorrectionstogauginos Gluino Chargino Neutralino Weaklyinteractingparticleshaveonlyweakradiativecorrections so charginosandneutralinosnaturallylighterthangluinos

  46. Whereis SUSY? Remind:Chargino/gluino ≈ 1/3 fromradiativecorrections So charginosmorelikelytobe in reachof LHC. However: Weakcrosssectionareweak: Observedat LHC: 250 WZ pairs (intoleptons) Expect: WinoZinopairswithmasses 5x as large: 250/5^4= 1/3 of an event. NEED MUCH MORE LUMI beforedeciding SUSY isdead. Expecttoreach 1 TeVcharginolimitonly after HL-LHC (≈ 2030 (3000/fb)

  47. Who cansee DM first? LHC ordirect DM Searches Answer: depends on model, seee.garXiv:1402.4650 CMSSM NMSSM XENON1T not sens. LHC 14 3000 /fb non-sens. region Higgs 125 allowed Higgs+W allowed LHC betterfor CMSSM (WIMP massrelatedtogluinomassbyrad. corr.) Direct DM searchesbetterfor NMSSM (WIMP massindep. of SUSY masses, sincesinglino)

  48. Example of SUSY production and decay chain

  49. Main SUSY signature: missing energy

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