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Comparing A ccelerator and direct Dark Matter searches

This presentation discusses the properties and possible origins of WIMPs in dark matter searches, examining various models and the effectiveness of theories in detecting dark matter at collider experiments like LEP, Tevatron, and LHC. References include key research by Bai, Fox, Harnik, Goodman, Busoni, Papucci, and the KICP workshop 2013. The discussion covers scenarios where WIMPs are in thermal equilibrium in the early universe and explains how effective theories are vital in interpreting missing momentum at colliders. The talk explores different portals, interactions, cross-sections, and operators related to WIMPs, providing insights into direct detection methods and the validity conditions of effective field theory. The presentation also delves into collider experiments, model-independent approaches, and the importance of EFT in interpreting dark matter phenomena.

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Comparing A ccelerator and direct Dark Matter searches

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  1. ComparingAccelerator and direct DarkMattersearches • WIMPS: • whatcanwesay about theirproperties? possible origins?  manymodels • Whatis an effective theory? • Detecting DM frommissingmomentumatcolliders: • LEP, Tevatron, LHC • Validity of effective theory • Some references: • Bai, Fox and Harnik, 1005.3797v2 • P. Fox et al., 1103.0240 • J. Goodman et al., 1008.1783, 1111.2359 • G. Busoni et al., 1307.2253, 1402.1275 • O. Buchmueller et al., 1308.6799 • M. Papucci et al., 1402.2285 • KICP workshop 2013: https://kicp-workshops.uchicago.edu/DM-LHC2013/presentations.php G. Azuelos Dark Matter workshop - Montreal

  2. Properties of WIMPS Dark Matter workshop - Montreal In earlyuniverse, WIMPS are in thermal equilibrium and annihilateuntil the densityistoolow  freeze-out Somepossibilities: LSP: neutralinos, gravitinos LKP: Kaluza-Klein state in Universal Extra dimensions LTP: Little Higgs with T parity also, in Technicolor, composite Higgs models Higgs portal Z’ portal fermion portal  useful to have a model-independentapproach In colliderexperiments: non-interacting, invisible particles missing ET

  3. Effective theories W Classic example: Fermi theory: Weak interaction is well approximated, in nuclear physics, by a contact interaction, when, in fact, it is an exchange of a heavy particle Dark Matter workshop - Montreal Assume new physics at some high energy scale L Energy scale at which measurement is performed: Q  Observed effect of new physics is small and needs to be calculated at 1st order only

  4. Effective approximation Propagator of the heavy particle: valid as long as (weak contact coupling) c q M c q (f = scalar mediator) Dark Matter workshop - Montreal

  5. Translate to Direct Detection time c q M c q Dark Matter workshop - Montreal

  6. Different kinematics Dark Matter workshop - Montreal

  7. Wimpsinteractingwithmatter c c c c c q c c h,H Z q q q q q q q c Dark Matter workshop - Montreal Assumingweak interactions (neutralinos): spin-independent: spin-dependent

  8. spin-dependent cross sections arXiv:1005.3797v2 atTevatron proton neutron Bai, Fox and Harnik Dark Matter workshop - Montreal

  9. Light mediator momentum and spin-dependent model arXiv:1005.3797v2 Bai, Fox and Harnik Dark Matter workshop - Montreal

  10. LEP shines light on Dark Matter 4 effective operators • single photon • cm energy ~ 200 GeV • central: 45o < q < 135o • forward: 12o< q < 32o • v. forward: 3.8o< q< 8o arXiv:1103.0240v1 simulated conditions, accounting for efficiencies as function of angle and resolutions P. Fox et al. Dark Matter workshop - Montreal

  11. DM nucleon scattering cross section arXiv:1103.0240v1 P. Fox et al. • also considered… • if lepton coupling only • limits on annihilation • lighter mediator effects strongconstraints on spin-dependentatlow mass: no A2dependence Dark Matter workshop - Montreal

  12. Operators Manycurvesobtained for the limits on L and for limitsderived on nucleon cross sections for the differentoperators arXiv:1008.1783v2 J. Goodman et al. Dirac Complexscalars Real scalars Dark Matter workshop - Montreal

  13. reach at colliders, in EFT spin-independent arXiv:1008.1783v2 J. Goodman et al. spin-dependent Dark Matter workshop - Montreal

  14. LHC ATLAS 1210.4391 Dark Matter workshop - Montreal

  15. Validity condition of EFT • Definition: ; Typically expect • condition for perturbativity: • mediator heavier than WIMP: • truncation of propagator expansion: • s-channel: arXiv:1307.2253 G. Busoni et al. The lower Q, the better the EFT approximation Dark Matter workshop - Montreal

  16. Momentum transfer Q k p1 p3 p2 p4 arXiv:1307.2253 G. Busoni et al. Dark Matter workshop - Montreal

  17. RL Fraction of cross section for which Q < L : for scalar operator: arXiv:1307.2253 G. Busoni et al. Dark Matter workshop - Montreal

  18. RL for scalar operator: arXiv:1307.2253 G. Busoni et al. Dark Matter workshop - Montreal

  19. Compared to ATLAS arXiv:1402.1275 G. Busoni et al. Dark Matter workshop - Montreal

  20. rUV/eff Ratio of cross sections obtained with UV completed theory (s-channel scalar mediator) and with EFT : arXiv:1307.2253 G. Busoni et al. The smalletpT and mc are, the better the EFT approximation. Dark Matter workshop - Montreal

  21. Beyond Effective Field Theory at the LHC • EFT is valid if • cross section enhanced if mediator is on-shell, for example • Consider CMS monojet analysis, as basis (7 and 8 TeV analyses) • Use Monte Carlo (MCFM 6.6) to simulate dark matter monojet process • includes full effects of mediator propagator and width, in s-channel • consider axial-vector and vector operators only: • apply CMS cuts • one hard jet: pT > 100 GeV • signal regions (best of their signal regions) • parton level cuts, with geometric acceptance • background simulated with MadGraph: • pythia showering and PGS detector simulation • compared results with CMS to validate their MC analysis arXiv:1308.6799 O. Buchmueller et al., Dark Matter workshop - Montreal

  22. Simplified model s-channel axial-vector interaction: applies also to Majorana DM, and more interesting spin-dependent limits EFT OK 2.5 TeV resonant production of mediator EFT OKwithin 20% resonant production of mediator EFT valid if M >> Q • Q > 500 GeV when pT(j) > 100 GeV, Etmiss > 400 GeV • find condition: M > 2.5 TeV Dark Matter workshop - Montreal

  23. Region 1: Very high mediator mass: EFT OK arXiv:1308.6799 O. Buchmueller et al., Dark Matter workshop - Montreal

  24. Region II : resonant enhancement • On-shell production of mediator if • production enhanced  EFT limit conservative arXiv:1308.6799 Region III for CMS conditions Region II for CMS conditions CMS EXO-12-048 PAS O. Buchmueller et al., see also Goodman & Shepherd, arXiv:1111.2359 Limit on L scales as ~ G-1/4 at the resonance peak Dark Matter workshop - Montreal

  25. Region III: very light mediator – EFT limit too strong • In the limit where the mediator is very light, • the cross section does not depend on its mass since • EFT assumes M is very large (and g small for the same L) arXiv:1308.6799 O. Buchmueller et al., Dark Matter workshop - Montreal

  26. Comparison to Direct Detection arXiv:1308.6799 O. Buchmueller et al., Dark Matter workshop - Montreal

  27. Recommendations and Conclusion • Validity of EFT depends a lot on the assumptions and parameters: • 4 parameters: • small dependence on width G in resonance region • LHC should provide limits on L in M-mcplane (in s-channel assumption?) • for few values of G/M Complementarity: M. Cahill-Rowley, 1305.6921 Dark Matter workshop - Montreal

  28. Extras Dark Matter workshop - Montreal

  29. tree level coupling to leptons only Dark Matter workshop - Montreal

  30. Assume coupling to leptons only Dark Matter workshop - Montreal

  31. Limits on Λ Dark Matter workshop - Montreal

  32. Upper limits on annihilation cross sections Dark Matter workshop - Montreal

  33. Annihilation cross section, compared to astronomicallimits LEP limitsbetterthan Fermi for low masses Dark Matter workshop - Montreal

  34. With different mediator masses strongdependence on width, if M > 2 mwimp, sinceitisproduced on-shell Dark Matter workshop - Montreal

  35. Wimp-Nucleus cross section Dark Matter workshop - Montreal

  36. Annihilation cross section Dark Matter workshop - Montreal

  37. Limits on L Bai, Fox and Harnik,arXiv:1005.3797 • monojetlimitsfrom CDF • ET(jet) > 80 GeV • Etmiss > 80 GeV • 2nd jet ET < 30 GeV • no add. jet with ET > 20 GeV Dark Matter workshop - Montreal

  38. spin-independent cross section Bai, Fox and Harnik,arXiv:1005.3797 proton very sensitive atlow masses tests alsocouplings to highergenerations Dark Matter workshop - Montreal need quark content of nucleon

  39. c c c c c q c c h,H Z q q q q q q q c http://www.worldscientific.com/doi/abs/10.1142/S0218301392000023?queryID=%24%7BresultBean.queryID%7D Dark Matter workshop - Montreal

  40. ATLAS 1210.4391 Dark Matter workshop - Montreal

  41. ATLAS 1210.4391 Dark Matter workshop - Montreal

  42. ATLAS 1210.4391 Dark Matter workshop - Montreal

  43. ATLAS mono-Z1404.0051 Dark Matter workshop - Montreal

  44. CMSEXO-12-048 PAS Dark Matter workshop - Montreal

  45. Bai, at DM workshop 2013 Dark Matter workshop - Montreal

  46. Bai, at DM workshop 2013 Dark Matter workshop - Montreal

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