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Searches For Supersymmetry with the DZero Detector at the Fermilab Tevatron

Searches For Supersymmetry with the DZero Detector at the Fermilab Tevatron. Mark S. Cooke (Columbia U.) on behalf of the D0 collaboration. SUSY10 Bonn, Germany 23 rd August, 2010. Tevatron: collisions at TeV. Over 9 fb -1 has been delivered in Run II !.

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Searches For Supersymmetry with the DZero Detector at the Fermilab Tevatron

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  1. Searches For Supersymmetry with the DZero Detector at the Fermilab Tevatron Mark S. Cooke (Columbia U.) on behalf of the D0 collaboration SUSY10 Bonn, Germany 23rd August, 2010

  2. Tevatron: collisions at TeV Over 9 fb-1 has been delivered in Run II ! DZero: well understood, multi-purpose detector Designed with the flexibility to observe beyond SM signatures in a variety of final states DZero and the Tevatron SUSY Searches at D0, M.S. Cooke (Columbia U.)

  3. Charginos & neutralinos in trileptons + • GMSB signature in • Hidden Valley SUSY, “lepton-jets” + • Bottom squarks in • Top squarks in • Sneutrinos as an resonance in R-parity violating SUSY D0 has recently performed SUSY motivated searches in several interesting final states, (also interpreted in a UED context) (also interpreted in a leptoquark context) Outline SUSY Searches at D0, M.S. Cooke (Columbia U.)

  4. Search for charginos and neutralinos in the trilepton final state 2.3 fb-1[PLB 680 (2009) 34] • “Classic” SUSY signature: • 3 isolated leptons+MET • Small SM backgrounds Major challenge is to achieve high efficiency in 3 lepton selection: 3rd leading lepton can be quite soft • Search categories: • 2 leptons (e.g. ee, μμ, eμ) + isol. track (l) • μτ + isol. track (l) • μτ + τhad SUSY Searches at D0, M.S. Cooke (Columbia U.)

  5. Trileptons (cont’d) Results No evidence for signal, limits “just above” Neutralino/chargino mass relations generally (1) 3 body decays: 2 cases shown, slepton masses “just” and “way” above chargino mass “way above” (2) Scan mSUGRA model mass relations, 2 and 3 body decays possible (3) BR to τ increases with tan(β) (2) (3) SUSY Searches at D0, M.S. Cooke (Columbia U.)

  6. Search for gauge mediated supersymmetry in the final state New! 6.3 fb-1[arXiv:1008.2133] Chargino/Neutralino production and cascade decays as in trilepton analysis, but also In GMSB, SUSY masses Gravitino doesn’t carry SM gauge very light (LSP) NLSP (prompt decay) Estimated with data SM Backgrounds: • No genuine • Genuine SM γγ, γ+jet, multi-jet missed ele track (W+γ,jet) W/Z+γγ (MC) SUSY Searches at D0, M.S. Cooke (Columbia U.)

  7. (cont’d) GMSB Results  For , expect: 6.9 ± 1.0 events observe: 4 events SPS8 GMSB: 5.2 ± 0.4 events @ Λ=120 TeV Consistent w/ SM expectation, In SPS8 context, limit (95% C.L.) excludes: SUSY Searches at D0, M.S. Cooke (Columbia U.)

  8. (cont’d) UED interpretation UED predicts a tower of KK states for each SM field, separated in mass by If UED in higher dim. space, grav. decays are induced. Assume: 1st Level Kaluza-Klein (KK) States after rad. corr. 95% C.L. limit excludes: SUSY Searches at D0, M.S. Cooke (Columbia U.)

  9. Search for Hidden Valley SUSY in final states with “lepton-jets” and 5.8 fb-1[D0 Note 6079-CONF] • Hidden valley models predict a weakly • coupled sector with a “dark photon” • force carrier which decays to “lepton-jets”. • Can appear in SUSY context in decay chains: Lepton-jet Dark LSPs PRL 103 081802 (2009) Previous search for Here D0 Preliminary SUSY Searches at D0, M.S. Cooke (Columbia U.)

  10. Search for bottom squark production in the final state 5.2 fb-1[arXiv:1005.2222] • Strong production of sbottom pairs • assumed • Decay kinematics set by Challenging Final State! • After b-tagging and selections to reduce MET mismeasurements, major backgrounds are from: • W/Z+cc/bb • top processes 0 SUSY Searches at D0, M.S. Cooke (Columbia U.)

  11. (cont’d) SUSY Results Exclude at 95% C.L. Leptoquark interpretation Charge ⅓ 3rd Generation Leptoquark for 100% for equal couplings SUSY Searches at D0, M.S. Cooke (Columbia U.)

  12. Search for top squark production in the final state 3.1 fb-1[D0 Note 5937-CONF] • Strong production • of stop pairs • Assume, 3-body eμ sample After cut, sensitivity assessed in 2D plane: depending on diff. rejection of WW and top vs. SUSY Searches at D0, M.S. Cooke (Columbia U.)

  13. Search for R-parity violating (RPV) production of a sneutrino resonance in the final state 5.3 fb-1[arXiv:1007.4835] Process probes trilinear RPV couplings: • Jet veto reduces top bkgd. • Events with • rejected if Remaining bkgd primarily DY(ττ) at low Meμ and diboson at high Meμ. SUSY Searches at D0, M.S. Cooke (Columbia U.)

  14. Chargino and neutralino pair production (tri-lepton, GMSB diphoton) • Stop and bottom pair production • Some special scenarios - RPV and Hidden Valleys • + new interpretations outside the SUSY context See also talks by F. Couderc (SUSY Higgs), S. Banerjee (long-lived) With a large dataset and a well understood detector, D0 continues the hunt for SUSY! No signals so far, but... best limits to date in several channels. Reported here today D0 searches for: Conclusions Tevatron to run through 2011, expected to deliver 12 fb-1 And new searches and further updates are also on the way! SUSY Searches at D0, M.S. Cooke (Columbia U.)

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