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Supersymmetry Without Prejudice: Dark Matter and LHC Searches in the pMSSM

Explore the comprehensive analysis of the phenomenological MSSM in the pMSSM framework with multiple constraints from collider, dark matter, and precision physics experiments. Discover the implications of LHC results on TeV-scale physics and the need for readiness to detect various signals.

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Supersymmetry Without Prejudice: Dark Matter and LHC Searches in the pMSSM

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  1. Supersymmetry Without Prejudice Dark Matter and LHC searches in the pMSSM Berger, Conley, Cotta, Gainer, JLH, Howe, Ismail, Le, Rizzo, Rowley arXiv:0812.0980, 0903.4409, 0909.4088, 1007.5520, 1009.2439, 1103.1697, 1105.1199, 1111.asap, ….

  2. Additional work on the pMSSM • A. Djouadi, J. L. Kneur and G. Moultaka, hep-ph/0211331 • Allanach etal: 1105.1024, 0904.2548 • Sekmen etal: 1109:5119 • Battaglia etal: 1110:3726 pMSSM = phenomenological MSSM

  3. Present Search Limits: Already Very Strong! Multi-Jet+MET Channel

  4. “Mq,g > 1 TeV”: Are we worried??? ~ ~

  5. Mq,g > 1 TeV: Are we worried??? ~ ~ Heck NO! • Only 1st fb-1 of a ~20 yr program • Only stop needs to be light to solve the hierarchy • Perhaps CMSSM is too simple and does not describe the Supersymmetry that Nature has realized • This is the maximum limit on squarks and gluinos

  6. LHC mSUGRA Discovery Reach (14 TeV)

  7. Only Stop-Squark Needs to be Light Barbieri @ Implications of LHC results for TeV-scale physics

  8. Supersymmetry With or Without Prejudice? • The Minimal Supersymmetric Standard Model has ~120 parameters • Studies/Searches incorporate simplified versions • Theoretical assumptions @ GUT scale • Assume specific SUSY breaking scenarios (mSUGRA, GMSB, AMSB…) • Small number of well-studied benchmark points • Studies incorporate various data sets • Does this adequately describe the true breadth of the MSSM and all its possible signatures? • The LHC is on, era of speculation is over ⇒ we need to be ready for all possible signals

  9. More Comprehensive MSSM Analysis • Study Most general CP-conserving MSSM • Minimal Flavor Violation • Lightest neutralino is the LSP • First 2 sfermion generations are degenerate w/ negligible Yukawas • No GUT, high-scale, or SUSY-breaking assumptions • ⇒ pMSSM: 19 real, weak-scale parameters scalars: mQ1, mQ3, mu1, md1, mu3, md3, mL1, mL3, me1, me3 gauginos: M1, M2, M3 tri-linear couplings: Ab, At, Aτ Higgs/Higgsino: μ, MA, tanβ These choices mostly control flavor issues producing a fairly general scenario for collider & other studies

  10. Perform 2 Random Scans 0812.0980 Log Priors 2x106 points – emphasize lower masses and extend to higher masses 100 GeV  msfermions  3 TeV 10 GeV  |M1, M2, |  3 TeV 100 GeV  M3  3 TeV ~0.5 MZ  MA  3 TeV 1  tan  60 10 GeV ≤|A t,b,|  3 TeV Linear Priors 107 points – emphasize moderate masses 100 GeV  msfermions  1 TeV 50 GeV  |M1, M2, |  1 TeV 100 GeV  M3  1 TeV ~0.5 MZ  MA  1 TeV 1  tan  50 |At,b,|  1 TeV 68422 survive 2908 survive

  11. Set of Constraints • Theoretical spectrum Requirements (no tachyons, etc) • Precision measurements: • Δ, (Z→ invisible) • Δ(g-2) • Flavor Physics • b →s , B →τν, Bs→μμ, Meson-Antimeson Mixing • Dark Matter • Direct Searches: CDMS, XENON10, DAMA, CRESST I • Relic density:h2 < 0.1210 → 5yr WMAPdata • Collider Searches: complicated with many caveats! • LEPII:Neutral & Charged Higgs searches, Sparticle production Stable charged particles • Tevatron:Squark & gluino searches, Trilepton search Stable charged particles, BSM Higgs searches • LHC: Higgs/SUSY searches, stable charged particles

  12. CMS Stable Particle Non-MET LHC searches are very important and have a significant impact on the pMSSM..but so far only in a negative way ! X ~ 8.1 k CMS A LHCb Bs X ~2.1 k X ~1.3 k

  13. Tevatron Squark & Gluino Search 2,3,4 Jets + Missing Energy (D0) Multiple analyses keyed to look for: Squarks-> jet +MET Gluinos -> 2 j + MET Feldman-Cousins 95% CL Signal limit: 8.34 events For each model in our scan we run SuSpect -> SUSY-Hit -> PROSPINO -> PYTHIA -> D0-tuned PGS4 fast simulation and compare to the data

  14. Perform NEW Random Scan Linear Priors 3x107 points 100 GeV  mL1,3/e1,3  4 TeV 400 GeV  mQ1,u1,d1  4 TeV 200 GeV  mQ3,u3d3  4 TeV 50 GeV  |M1|  4 TeV 100 GeV  |M2, |  4 TeV 400 GeV  M3  4 TeV |At,b,|  4 TeV 100 GeV  MA  4 TeV 1  tan  60 223,256 survive Performing LHC MET-based analyses now

  15. Perform NEW Random Scan Linear Priors 3x107 points 100 GeV  mL1,3/e1,3  4 TeV 400 GeV  mQ1,u1,d1  4 TeV 200 GeV  mQ3,u3d3  4 TeV + Gravitino LSP 1 ev  m3/2  500 GeV log scan 50 GeV  |M1|  4 TeV 100 GeV  |M2, |  4 TeV 400 GeV  M3  4 TeV |At,b,|  4 TeV 100 GeV  MA  4 TeV 1  tan  60 Need to include BBN constraints, include spin 3/2 in public codes: in process

  16. Uncertainties in Spectrum Generation Ratios of sparticle masses Suspect/Soft-SUSY Gluino eL uL

  17. New Scan Results (LSP=χ)

  18. New Scan Results (LSP=χ)

  19. New Scan Results (LSP=χ) Left Squarks Right Squarks

  20. New Scan Results (LSP=χ) g-2 b→sγ Bs→μμ B→τν tanβ Log Ωh2

  21. pMSSM Model Generation LHC & LC Fermi/Pamela Indirect Detection CDMS/XENON Direct Detection ICE3 ???

  22. Supersymmetry Without Prejudice @ the LHC • Issue: Can the LHC observe all the pMSSM model points? • Procedure: We asked whether or not a standard set of LHC • MET analyses, designed for the CMSSM, would see them. • To be as realistic as possible we worked closely w/ ATLAS • employing their SUSY analysis suite at the fast simulation • level. We obtained their pre-data SM background estimates • & employed their anticipated range of systematic errors. • We followed their search analyses in detail (same cuts, etc.) • as well as their statistical criterion for SUSY discovery for • direct comparisons.

  23. We first verified that we can approximately reproduce both • the 7 & 14 TeV ATLAS results for their benchmark CMSSM • models with our analysis techniques for each channel. • We then passed all of ~71k points through the full suite • of ATLAS MET analyses (~150 core-yrs of CPU) • SuSpect  SUSY-Hit  PROSPINO (~12M K-factors!)  • PYTHIA  ATLAS-tuned PGS4 fast simulation • Many results! • (ATLAS = ATool for Locating Any SUSY )

  24. ATLAS FEATURE SuSpect generates spectra with SUSY-HIT# for decays NLO cross section for ~85 processes using PROSPINO** & CTEQ6.6M PYTHIA for fragmentation & hadronization PGS4-ATLAS for fast detector sim ISASUGRA generates spectrum & sparticle decays NLO cross section using PROSPINO & CTEQ6M Herwig for fragmentation & hadronization GEANT4 for full detector sim ** version w/ negative K-factor errors corrected # version w/o negative QCD corrections & with 1st & 2nd generation fermion masses included as well as explicit small m chargino decays

  25. Comparison with ATLAS Benchmark Points 7 TeV 3j0l 4j0l 4j1l 2j0l

  26. 14 TeV 4j ^

  27. Signal Events Required for S=5 Depends on the Meff cut which is now ‘optimized’ 400 800 1200 1600 7 TeV

  28. pMSSM Model Coverage: Flat Priors Solid=4j, dash=3j, dot=2j final states Red=20%, green=50%, blue=100% background systematic errors

  29. Log-Priors Solid=4j, dash=3j, dot=2j final states Red=20%, green=50%, blue=100% background systematic errors

  30. Fraction of models that are found by n analyses @7 TeV (with B=20%)  The results are highly sensitive to the background uncertainty

  31. Search ‘effectiveness’: If a model is found by only 1 analysis which one is it?? B=20% 4j0l is the most powerful analysis…

  32. pMSSM coverage @ 7 TeV summed over all analyses The coverage is quite good for both model sets ! Log Flat  

  33. This S. Caron & A. Stuebing Freiberg ATLAS/SUSY study of our model sets The1st 500 Flat Models Preliminary

  34. Signal Significance (summed over all channels) L=10 fb-1 and B=20% Benchmark Models? We are working with both ATLAS & CMS SUSY groups in studying these low-S models in detail These models will be hard to find no matter what the lumi is… FLAT

  35. The Undiscovered SUSY Why are Models unobservable? • The most obvious things to look at first are : • small signal rates due to suppressed ’s • which can be correlated with large sparticle masses • small mass splittings w/ the LSP (compressed spectra) • decay chains ending in stable charged sparticles •  BUT there are many more subtle situations that have to • be examined on a case-by-case basis

  36. Cross Sections: Squark & gluino production cross sections @ 7 TeV cover a very wide range & are correlated with the search significance. But there are models with  ~100 pb that are missed by all ATLAS analyses while others with  below ~100 fb are found. Cross Sections: Squark & gluino production cross sections @ 7 TeV cover a very wide range & are correlated with the search significance. But there are models with  ~100 pb that are missed by all ATLAS analyses while others with  below ~100 fb are found. 4j0l 7 TeV

  37. Compressed Spectrum: Both 7 & 14 TeV models can be missed due to small mass splittings between squarks and/or gluinos and the LSP  softer jets or leptons not passing cuts. ISR helps in some cases…

  38. Missed vs Found Model Comparisons 47772-passes 38036-fails • 38036 (~2.5 pb) fails while 47772 (~1.7 pb) passes all nj0l • uR lighter (~500 vs ~635 GeV) & produces larger  in 38036 • & decays ~75% to j+MET • BUT due to the m w/ LSP difference ( eff ~13% vs ~3.5% ) • 38036 fails to have a large enough rate after cuts • Efficiency wins over cross section

  39. Missed vs Found Model Comparisons 21089-fails 34847-passes Florida Greenup, KY

  40. What went wrong ?? • 21089 ( ~ 4.6pb) & 34847 ( ~ 3.3pb) yet both models fail • nj0l due to smallish m’s. BUT 34847 is seen in the lower • background channels (3,4)j1l • In 34847, uR cascades to the LSP via 20 & the chargino • producing leptons via W emission. The LSP is mostly a wino • in this case. • In 21089, uR can only decay to the lighter ~Higgsino • triplet which is sufficiently degenerate as be incapable of • producing high pT leptons • Note that the jets in both uR decays have similar pT’s

  41. Missed vs Found Model Comparisons 10959-fails 68329-passes

  42. What went wrong ?? • 68329 passes 4j0l (~4.6 pb) while 10959 (~6.0 pb) fails all • In 68329, dR decays to j+MET (B~95%) since the gluino is • only ~3 GeV lighter. The gluino decays to the LSP via the • sbottom (B~100%) with a m~150 GeV mass splitting . The • LSP is bino-like in this model • In 10959, dR decays via the ~107 GeV lighter gluino (B~99%) • and the gluino decays (with m ~40 GeV) through sbottom • & 2nd neutralino to the (wino-like) LSP (with m~ 60 GeV). • Raising the LSP & b1 masses in 68239 by 50 GeV (the 2nd • set of curves) induces failure

  43. Missed vs Found Model Comparisons 8944 21089

  44. What went wrong ?? • 8944 seen in (3,4)OSDL while 21089 is completely missed • nj0l fail due to spectrum compression but with very similar • colored sparticle total  = (3.4, 4.6) pb • models have similar gaugino sectors w/ 1,20 Higgsino-like • & 30 bino-like • 30 can decay thru sleptons to produce OSDL + MET • However in 8944, the gluino is heavier than dR so that dR • can decay to 30 • But in 21089, the gluino is lighter than uR so that it decays • into the gluino & not the bino so NO leptons

  45. Missed vs Found Model Comparisons 9781 20875

  46. What went wrong ?? • 9781 seen in 2jSSDL while 20875 is completely missed • nj0l fail due to spectrum compression but with very similar • colored sparticle total  = (1.1, 1.3) pb • Both models have highly mixed neutralinos & charginos w/ • a relatively compressed spectrum • In model 9781, uR can decay to leptons+MET via the bino • part of 20 via intermediate e, sleptons • But in 20875, these sleptons are too heavy to allow for decay • on-shell & only staus are accessible. The resulting leptons • from the taus are too soft to pass analysis cuts

  47. A 14 TeV Example: Missed Found

  48. What went wrong ?? • In 43704: gluinos dR 20 W + ‘stable’ chargino (~100%) • as the 20 –LSP mass splitting is ~91 GeV • In 63170: gluinos uR 20  Z/h + LSP (~30%) as the • 20 –LSP mass splitting is larger ~198 GeV • Again: a small spectrum change can have a large effect on • the signal observability! •  Searches for stable charged particles in complex cascades • may fill in some gaps as they are common in our model • sets (Zanesville, OH) (St. Louis, MO)

  49. Fine-Tuning SUSY ? It is often claimed that if the LHC (@7 TeV) does not find anything then SUSY must be VERY fine-tuned & so ‘less likely’. Is this true for our pMSSM model sets?? FLAT

  50. A few results on Dark Matter

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