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Little Higgs Dark Matter and Its Implications at the LHC

Little Higgs Dark Matter and Its Implications at the LHC. Chuan-Ren Chen (NTNU) HEP Seminar @ AS, 5 /30/2014. In collaboration with H-C Tsai, M-C Lee, 1402.6815[ hep-ph ]. predictions explanations. Outline. EXP, OBS. BSM. constraints evidences. LHT. Higgs boson.

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Little Higgs Dark Matter and Its Implications at the LHC

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  1. Little Higgs Dark Matter and Its Implications at the LHC Chuan-Ren Chen (NTNU) HEP Seminar @ AS, 5/30/2014 In collaboration with H-C Tsai, M-C Lee, 1402.6815[hep-ph]

  2. predictions explanations Outline EXP, OBS BSM constraints evidences LHT CRC (NTNU)

  3. Higgs boson July 4 2012 @ CERN Higgs boson is discovered, a significant step for understanding of EWSB! CRC (NTNU)

  4. Naturalness “Problem” Higgs is naturally ~ 200 GeV CRC (NTNU)

  5. e.g. Supersymmetry CRC (NTNU)

  6. Little Higgs Model , Kaplan… 100 CRC (NTNU)

  7. Littlest Higgs Model CRC (NTNU)

  8. Littlest Higgs Model gauge symmetries are embedded in global SU(5) kinetic term top sector CRC (NTNU)

  9. Cancellation CRC (NTNU)

  10. Little Higgs Model CRC (NTNU)

  11. Little Higgs Model w/ T-parity CRC (NTNU)

  12. Yukawa Sector CRC (NTNU)

  13. Top Sector CRC (NTNU)

  14. particle spectrum T-parity Even T-parity Odd SM * parameters: f, kq, kl, λ1, mh * The lightest T-odd particle is stable dark matter candidate CRC (NTNU)

  15. EW constraints CRC (NTNU)

  16. Unitarity Belyaev, CRC, Tobe, Yuan, hep-ph/0609179 constraining λ’s CRC (NTNU)

  17. T-odd Fermions Cao, CRC, 0707.0877 CRC (NTNU)

  18. Higgs Pheno. CRC, Tobe, Yuan, hep-ph/0602211 mh(GeV) t, T+, q- gg -> h production is always suppressed CRC (NTNU)

  19. Higgs Pheno. CRC, Tobe, Yuan, hep-ph/0602211 Han, Wang, Yang, Zhu, 1301.0090 gg -> h -> γγ is suppressed CRC (NTNU)

  20. Dark Matter Some evidences A nonbaryonic, “dark”, charge-neutral object which interacts weakly with normal matters CRC (NTNU)

  21. Dark Matter at LHT two possible candidates: heavy photon, T-odd neutrinos T-odd partner of photon T-odd partner of neutrino dark matter: CRC (NTNU)

  22. Dark Matter & LHT HOWEVER Planck+WMAP Ωh2 >> XENON100 Direct search of DM excludes can fit relic density data well. CRC (NTNU)

  23. Dark Matter & LHT two possible candidates: heavy photon, T-odd neutrinos T-odd partner of photon T-odd partner of neutrino dark matter: dark matter: CRC (NTNU)

  24. Dark Matter & LHT Mh = 125 GeV solution? Yes, MAH ≳Mh/2 For heavier AH, co-annihilations with T-odd fermionsare needed! CRC (NTNU)

  25. co-annihilation w/ T-odd leptons (T-odd quarks are heavy!) CRC (NTNU)

  26. w/ light T-odd leptons Mh = 125 GeV Planck2013 + WMAP-9yrs are so light! LHC should be able to produce lots of them. CRC (NTNU)

  27. light T-odd leptons at LHC 8 TeV lepton + met dilepton + met met only f (GeV) large production cross section 1 ~ 10 pb 100% CRC (NTNU)

  28. dilepton + MET search at LHC: slepton pair or chargino pair in SUSY NO Constraint dilepton + met arbitrary Pt(e) (GeV) CRC (NTNU)

  29. dilepton + MET search at LHC: slepton pair or chargino pair in SUSY NO Constraint dilepton + met MT2 (GeV) kill all signals arbitrary CRC (NTNU)

  30. lepton + met one lepton + MET search at LHC: search for W’ one high pt lepton + large MT f (GeV) MT > 1 TeV kill signal NO constraint from current data MT (GeV) CRC (NTNU)

  31. light T-odd leptons at LHC 8 TeV lepton + met soft dilepton + met soft met only f (GeV) charged lepton is soft! arbitrary direct search is very challenging! can contribute mono-jet + met signal at LHC Pt(e) (GeV) CRC (NTNU)

  32. w/ light T-odd leptons Mh = 125 GeV Direct search: CRC (NTNU)

  33. co-annihilation w/ T-odd quarks (T-odd leptons are heavy!) CRC (NTNU)

  34. w/ light T-odd quarks degenerate case 3 down-type: 3 up-type: ∵ ( Mt_ - MAH ) < MW<Mtop However, top partner ONLY has 4-body decay channel, decay life time is too long! inconsistent with stable heavy quark search at colliders CRC (NTNU)

  35. w/ non-degenerate T-odd quarks projective LUX 2014 can explore MAH up to ~190 GeV, future expts can explore whole parameter space. CRC (NTNU)

  36. light T-odd quarks at the LHC arbitrary HUGE production cross section, jet pT is very soft! dijet + MET search is very challenging! Pt(j) (GeV) CRC (NTNU)

  37. light T-odd quarks at the LHC soft contributes to mono-jet BSM search at LHC. CRC (NTNU)

  38. light T-odd quarks at the LHC 95% C.L. exclusion 2.8 pb allow one other jet > 35 GeV 0.02 pb 0.16 pb 0.05 pb f < ~1.4 TeV (MAH< ~ 220 GeV) is DISFAVORED. CRC (NTNU)

  39. Summary • With Mh = 125 GeV, co-annihilation is needed for heavier (not ~ Mh/2) dark matter in LHT model to explain current universe. • In co-annihilation region, T-odd new heavy fermions should be very light, large production cross section at the LHC. • The small mass difference between dark matter and T-odd leptons makes collider search very difficult. • light T-odd top quark partner decays “too late” -> not allowed by collider searches. • mono-jet + MET from light T-odd quarks + 1jet production at the LHC exceed current limit if MAH< 220 GeV. • Future DM direct search exps can explore whole parameter space. CRC (NTNU)

  40. Back UP CRC (NTNU)

  41. Little Hierarchy Problem Effective SM Schmaltz et al, hep-ph/0502182 and references therein New Physics should be larger than 5 TeV tension between 1 TeV and 5 TeV!! CRC (NTNU)

  42. CRC (NTNU)

  43. CRC (NTNU)

  44. EW constraints CRC (NTNU)

  45. “heavy neutrino” can NOT be a dark matter elastic scattering w/ nuclei KK neutrino in UED model relic density same as SM coupling ~ 2x10-3pb >> 10-9pb (current limit) Servant, Tait, hep-ph/0206071 Servant, Tait, hep-ph/0209262 CRC (NTNU)

  46. mono-jet +MET at LHC 95% C.L. exclusion 2.8 pb 0.02 pb 0.16 pb SR3: jet Pt > 350 GeV 0.05 pb NO constraint from current data CRC (NTNU)

  47. “Solution” CRC (NTNU)

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