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Supersymmetry Without Prejudice

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, …. Additional work on the pMSSM.

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Supersymmetry Without Prejudice

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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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