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Exotics at the LHC Sam Harper (RAL, STFC) UK HEP Forum 08/09/11

Exotics at the LHC Sam Harper (RAL, STFC) UK HEP Forum 08/09/11. EXO Searches at LHC. correct! (and thanks for inviting me to give this talk Ian  ). from Ian’s EXO HEP Forum UK talk last year: Huge number of Exotic results out ATLAS: 15 papers CMS: 20 papers

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Exotics at the LHC Sam Harper (RAL, STFC) UK HEP Forum 08/09/11

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  1. Exotics at the LHC Sam Harper (RAL, STFC) UK HEP Forum 08/09/11 Sam Harper - Exotics - HEP Forum UK

  2. EXO Searches at LHC correct! (and thanks for inviting me to give this talk Ian  ) • from Ian’s EXO HEP Forum UK talk last year: • Huge number of Exotic results out • ATLAS: 15 papers • CMS: 20 papers • will only focus on results with 2011 data • some interesting results missed sadly • 7 ATLAS, 18 CMS results with 2011 data Sam Harper - Exotics - HEP Forum UK

  3. Exo 2011 Searches see recent “Implications of LHC results for TeV-scale physics” https://indico.cern.ch/conferenceOtherViews.py?view=standard&confId=141983 for a more detailed set of talks • New Gauge Bosons • di-lepton, di-jet, ttbar, di-lepton+di-jet final states, lepton+MET, WZ • Extra Dimensions • di-fermion, di-photon, jet+MET, photon + MET • Long Lived • displaced muons/electrons • stopped gluinos • 4thGeneration fermions • t’, b’, T • The Truly Exotic…. • blackholes, heavy stable charged particles, W+dijet Sam Harper - Exotics - HEP Forum UK

  4. New Gauge Bosons Sam Harper - Exotics - HEP Forum UK

  5. Z’->ee / µµ UK effort both ATLAS + CMS! *ATLAS accxeff quoted at 1.5 TeV but should be similar at 1 TeV • classic discovery channel: • inclusive search: mass of 2 leptons |η|<2.5, no cuts on MET / other activity in event • no OS required eles / OS required muons • excitement early on this year but sadly died away • no significant excess: • highest in CMS: 970 GeV, local: 2.1sigma • with LEE effect, 0.2 sigma • ATLAS doesn’t quote highest excess, its either ~570 GeV or ~950 GeVwith similar significance to CMS Sam Harper - Exotics - HEP Forum UK

  6. Z’->ee / µµ • classic discovery channel: • inclusive search: mass of 2 leptons |η|<2.5, no cuts on MET / other activity in event • no OS required eles / OS required muons • excitement early on this year but sadly died away • no significant excess: • highest in CMS: 970 GeV, local: 2.1sigma • with LEE effect, 0.2 sigma • ATLAS doesn’t quote highest excess, its either ~570 GeV or ~950 GeV with similar significance to CMS *ATLAS accxeff quoted at 1.5 TeV but should be similar at 1 TeV Sam Harper - Exotics - HEP Forum UK

  7. Z’->ee / µµ: Limits Z’ SSM limits • limits: • ATLAS/CMS about the same ele • CMS does much better muons • note: CMS missed the cu–cd from this update due to lack of time but will happen for next update Sam Harper - Exotics - HEP Forum UK

  8. 35pb-1 to 1.1fb-1 • Z’->ee/µµ exclusion from 0.05pb to 0.002pb • large jump in sensitivity • thanks LHC! Sam Harper - Exotics - HEP Forum UK

  9. Z’/W’->di-jet • search di-jet resonance • CMS |η|<2.5, |Δη|<1.3, ATLAS, |η|<2.8 |y*|<0.6 • good agreement with data to fit parameterisation • no evidence of any significant excess Sam Harper - Exotics - HEP Forum UK

  10. Z’/W’->di-jet excited quark limits CMS also quotes W’ limit of: 1-1.55 TeV • limits are final state dependent • FSR reduces resolution • gg final states: more FSR, worse resolution, worse limits • ATLAS better jet resolution means they are slightly ahead Sam Harper - Exotics - HEP Forum UK

  11. Z’/W’->dijet: Wide Jets combine into single ‘wide jet’ • inspired by recent jet grooming algos • aim is to improve FSR recovery and therefore resolution • previously used Anti-kT 0.7 jets • wide jet algo starts with anti-kT 0.5 jets • identifies two leading jets • for each of these jets, sums in all surrounding jets in ΔR cone of 1.1 • gg states have more FSR • wide jet algo improves resolution • reduces differences between qq, qg and gg limits Sam Harper - Exotics - HEP Forum UK

  12. Z’->ttbar UK effort on ATLAS here! • top particle can be special in BSM theories • new physics can preferentially couple to it • important channel to study • current analyses: • semi-leptonic • di-lepton modes • fully hadronic (boosted) Sam Harper - Exotics - HEP Forum UK

  13. Z’->ttbar • top particle can be special in BSM theories • new physics can preferentially couple to it • important channel to study • current analyses: • di-lepton modes • semi-leptonic • fully hadronic (boosted) Sam Harper - Exotics - HEP Forum UK

  14. W’->eν / μν • non-resonant signature due to MET • look for excess in high end tail • similar to Z’ analysis, just replace 1 lepton with MET • efficiency: ~80% in both channels • CMS uses particle flow based MET • excellent agreement between SM + data • no hint of any excess in 1fb-1 • see what 2011 dataset offers • set limits using Bayesian cut and count above MT threshold optimized on signal samples Sam Harper - Exotics - HEP Forum UK

  15. W’->eν / μν W’ mass limits • σ.Br limits both very similar • ATLAS slightly better expected, CMS better obs • ATLAS: • ~8fbat 1 TeV to ~10fb at 2.5 TeV • CMS: • ~7fb at 1.4 TeV to ~9fb at 2.5 TeV Sam Harper - Exotics - HEP Forum UK

  16. W’->WZ->3lν, l=e,μ HT Cut for 600 GeV W’ • event selection: • 2 same flavour opposite charge leptons with 60<Mll < 120 • 1 more high pT lepton + MET > 30 GeV • HT cut, optimised for each W’ mass • analysis motivated by technicolor • limits set by Bayesian cut and count technique Sam Harper - Exotics - HEP Forum UK

  17. W’->WZ->3lν, l=e,μ HT Cut for 600 GeV W’ • event selection: • 2 same flavour opposite charge leptons with 60<Mll < 120 • 1 more high pT lepton + MET > 30 GeV • HT cut, optimised for each W’ mass • analysis motivated by technicolor • limits set by Bayesian cut and count technique Sam Harper - Exotics - HEP Forum UK

  18. WR + Heavy Neutrino • searches for WR to heavy ν predicted by L-R SM extension • require 1 lepton > 60 GeV • accxeff: 50% ele, 60% muons Sam Harper - Exotics - HEP Forum UK

  19. Planck TeV Bulk (y) Extra Dimensions Sam Harper - Exotics - HEP Forum UK

  20. Di-Photon UK effort on ATLAS here! RS Graviton Mass Limits (TeV) • favoured channel for ED • factor 2 high BR to photons over eles/muons • requires two photons with ET > 70 GeV, |η|<1.44 • data driven background estimates of jet background • di-photon background from pythia reweighted by mass dependent NLO k-factor from DIPHOX+GAMMA2MC • searches for both warped (resonant) and ADD (non-resonant) scenarios Sam Harper - Exotics - HEP Forum UK

  21. Mono Jet UK effort on ATLAS + CMS! • searches for jet + MET • benchmark model: ADD extra dim • main background: Z->νν+ jets • estimate from Z->μμ + jet events • limits are cut and count above optimised jet/ MET thresholds Sam Harper - Exotics - HEP Forum UK

  22. Mono Photon • searches for γ + MET • pho ET > 95 GeV, |η|<1.44 + MET> 80 GeV • benchmark model: ADD extra dim • main background: Z->νν+γ • estimate direct from MC • estimate jet backgrounds from data Sam Harper - Exotics - HEP Forum UK

  23. fourth family Sam Harper - Exotics - HEP Forum UK

  24. t’->bW • search for t’t’ ->bWbW • iettbar search but with higher mass • done in lepton+jets, di-lepton channels • uses mass techniques used in top mass methods Sam Harper - Exotics - HEP Forum UK

  25. t’->bW • limits set using CLS method on measured mass spectra • t’ mass limit: • dilepton: 422 GeV • lepton + jet: 450 GeV Sam Harper - Exotics - HEP Forum UK

  26. T->tZ • search for vector like charge 2/3 quark decaying to tZ • can appear in UED, composite Higgs models, Little Higgs • signature: • Z->ee/μμ + 1e/μ + 2 jets • eles > 20 GeV, jets > 25 GeV, muons > 15 GeV • search variable: • ST = Σ jet + leppT • cut ST > 80 GeV • total acc: • 14-35% from 250 to 550 GeV Sam Harper - Exotics - HEP Forum UK

  27. b’->tW • signature: • 2 same sign leptons + 2 jets (1 b-tag) • 3 lepton (2 opp sign) + 1 b-tag jet • looks for excess in ST distribution Sam Harper - Exotics - HEP Forum UK

  28. Long Lived Sam Harper - Exotics - HEP Forum UK

  29. Displaced leptons UK effort on CMS here! from MC cosmic data data / MC difference leads to 20% uncertainty on displaced track eff • search for neutral objects decaying to ele/mu pairs • eg H0-> 2X, X->l+l- • look for tracks with large transverse impact parameter Sam Harper - Exotics - HEP Forum UK

  30. Displaced Leptons estimate backgrounds from extrapolation of decay length significance • signal selection: • high transverse impact cut significance • pT > 38 GeV (ele), 25 GeV (mu) • have dedicated trackless triggers • muons: expect 0, obs 0 • electrons: some bkg around Z Sam Harper - Exotics - HEP Forum UK

  31. Stopped SUSY UK effort on CMS here! • looks for long lived particles stopping in CMS • specifically the central region of HCAL • 40-50% gluinos, 30-20% stops stop • trigger on 50 GeV jets when there is no beam • main bkgs: beam halo, comics, detector noise • cuts reduce event rate to O(10-5Hz) • 12-13% efficient for stopped particles • probes lifetimes from 75ns to ~2 weeks Sam Harper - Exotics - HEP Forum UK

  32. Exotic Exotics Sam Harper - Exotics - HEP Forum UK

  33. Same Sign Muon Pairs • a catch all exo search • same sign di-lepton signatures come from variety of models • main motivation is double charged Higgs • searches for two SS muons, pT > 20/10 GeV, |η|<2.5 • sets model independent limits total cross-section above mass M Sam Harper - Exotics - HEP Forum UK

  34. W+2jets • follow up on the CDF bumpusing cuts as close as possible to CDF • no excess observed Sam Harper - Exotics - HEP Forum UK

  35. Blackholes UK effort on ATLAS here! CMS UK also starting out 9 jet candidate with ST =2.6 TeV • searches for high ST events • ST: ΣpT of all objects > 50 GeV in event (including MET) • low multiplicity (N=2,3) control region • ST shape of QCD bkg independent of number of final state objects • fit to this region to get bkg shape • search for new physics in high multiplicity region (N>3) Sam Harper - Exotics - HEP Forum UK

  36. Blackholes no evidence of any signal set limits on various black hole types Sam Harper - Exotics - HEP Forum UK

  37. Summary • CMS + ATLAS have produced many many exotic searches for new physics • huge phase space explored where new physics could have been lurking • no significant deviation seen in any channel • slightly concerning • but on other hand shows we understand our detectors very well • but good news: the LHC is delivering lots of lumi, our detectors are working perfectly • all we need now is nature to be kind to us  (and to make sure we trigger on it…) Sam Harper - Exotics - HEP Forum UK

  38. References • for much more information please see: • https://twiki.cern.ch/twiki/bin/view/AtlasPublic/ExoticsPublicResults • https://twiki.cern.ch/twiki/bin/view/CMSPublic/PhysicsResultsEXO Sam Harper - Exotics - HEP Forum UK

  39. Backups Sam Harper - Exotics - HEP Forum UK

  40. Z’->ττ EXO-10-022 • actively being worked for 2011 • stay tuned… • low backgrounds but complicated final state • acceptance: of order ~15% at 1 TeV over all channels • MET in final state means Z’ is wide, signal will not be as clear cut as in light leptons • Bayesian binned likelihood for limits Sam Harper - Exotics - HEP Forum UK

  41. W’->eν / μν • non-resonant signature due to MET • look for excess in high end tail • similar to Z’ analysis, just replace 1 lepton with MET • 0.4 < pT/ ETmiss<1.5 , Δϕ > 2.5 • acceptance: 80% in both channels • excellent agreement between SM + data • no hint of any excess in 1fb-1 • see what 2011 dataset offers • set limits using Bayesian cut and count • exclusion W’ up to 2.27 TeV Sam Harper - Exotics - HEP Forum UK

  42. W’/Z’ Summary *limit at 0.9 TeV Sam Harper - Exotics - HEP Forum UK

  43. e*/μ* arXiv:1107.1773 • searches for excited states of composite fermions with scale Δ • pp->ll*->llγ • update in progress for 2011 Sam Harper - Exotics - HEP Forum UK

  44. Leptoquarks • search for pair production of lepto quarks • not yet updated to 2011 data • search in following channels: • eejj, μμjj, eνjj • no excess is found Sam Harper - Exotics - HEP Forum UK

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