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Search for new physics at the Tevatron

Search for new physics at the Tevatron. Pedro Mercadante IFT/UNESP. On behalf of DZero and CDF collaborations. Tev Energy Scale. Why is the TeV scale special? It is the scale of EW symmetry breaking We don´t know how masses are generated

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Search for new physics at the Tevatron

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  1. Search for new physics at the Tevatron Pedro Mercadante IFT/UNESP OnbehalfofDZeroand CDF collaborations Pedro Mercadante

  2. TevEnergyScale • Why is the TeV scale special? • It is the scale of EW symmetry breaking • We don´t know how masses are generated • In the Standard Model the Higgs mechanism is evoked (Barbara´s talk) • New Physics Beyond Standard Model? • Supersymmetry • Extra Dimensions • Other models Pedro Mercadante

  3. Past and Future Accelerators Pedro Mercadante

  4. Tevatron Run IIStill at the Energy Frontier Chicago  DØ CDF p Tevatron p Antiproton Injector Recycler • Accelerator • pp • 1.96 TeV • L = 4-5 fb-1 to be analyzed. In this talk 1-3 fb-1 results will be presented • Detectors • Good coverage • Good particle identification Pedro Mercadante

  5. Detectors DZero Detector CDF Detector Pedro Mercadante

  6. Integrated Luminosity 3 fb-1 Aug 2007 Pedro Mercadante

  7. Supersymmetry The MSSM Minimalsupersymmetricmodel Two Higgs doublet SM + Superpartners µ parameter tan  Superpotential Soft Terms Scalar Masses (m0) GauginosMasses (m1/2) Trilinear(A) Parameter Bilinear (B)Parameter Pedro Mercadante

  8. SupersymmetryWhich SUSY? • mSUGRA (Constrained MSSM) m0, m1/2, tan , A, sign μ • gluino + squark • gluino + sbotton • trilepton • AMSB and GMSB • R parityViolationModels Pedro Mercadante

  9. mSugragluinos (jet + missing ET)cdfarXiv:0811.2512 PLB 660,449 • General search: gluino + squarksproduction • Jets + missingET • MissingET • 2,3,4 Jets; pT > 25 GeV • Angles • Lepton veto Pedro Mercadante

  10. Results • Resultsonsquarkandgluinomass. • For squarkmass = gluinomass-> m > 392 GeV • Results in the plane m0 X m1/2 • DZerohas similar limits Pedro Mercadante

  11. mSugragluinos (b-jet + missing ET)http://www-cdf.fnal.gov/physics/exotic/r2a/20080821.bbmet_gluinosbottom/ • Gluino -> Sbottons • Jets + missing ET • 2 jets • 1 b tag • 2 b tag Pedro Mercadante

  12. mSugraCharginos(trileptons)D0 arXiv:0901.0646 • Cuts: • Two set ofpTcut • Invariantmass, angular cut • Transversemass, missing ET , jet veto • TrackpT • Invariantmassl-track • TrileptonSignal: Cleansignal • Modeldependent • 4 channelspTl > 12, 8 GeV • e,e, l • e,μ,l • μ, μ,l • μ ,τ, l • In allchannelsthe extra lepton is a track Pedro Mercadante

  13. mSugraCharginos(trileptons) Limits for σ X BR Best limitsonthecontextofmSugra Similar search from CDF publishedwith 2 fb-1 http://www-cdf.fnal.gov/physics/exotic/r2a/20080110.trilepton_dube/ Pedro Mercadante

  14. Extra DimensionsAre therenew extra Dimension? • Large Extra Dimensions (ADD models) • Onlygravitypropagates in the extra dimensions • Directsignal: missing ET fromthesumof KK states propagating in thebulk • Indirectsignal: sumof KK towersmodifytheproductionof SM particles • Universal Extra Dimensions • Allparticlescanpropagate in the extra dimensions. Allparticlehavenewexcited states • Signals are similar to thoseof SUSY • RandallSundrummodels • Excited states ofgravitons are heavy. Mightbeproducedanddecay in pairsof SM particles Pedro Mercadante

  15. Large Extra DimensionsDirectsignal: photon + missing ETD0 PRL 101, 011601 • Selection • pT> 90 GeV, missing ET > 70 GeV • Background • NonCollision • Miss identifiedjet • Z + gamma • No jets (pT > 15 GeV), no Leptons (muons, trackswithpT> 8 GeV) 51 Data Events 49.9 expected Pedro Mercadante

  16. Limits Limits are set dependingonthenumberof extra dimension For n=2,3,4 M > 970, 899, 867 GeV CDF has similar results(PRL 101, 181602) Pedro Mercadante

  17. LED Virtual Gravitonexchange: Diphotonsanddielectrons D0 arXiv:0809.2813 • Sensitive to thecutoff • Selection: • Eletromagnetic (EM) cluster with PT > 15 GeV • Central andendcap cluster (CC-EC) • Background • Drell Yan andγγproduction • Multijet Pedro Mercadante

  18. Randall-SundrumZZ resonance http://www-cdf.fnal.gov/~boveia/blessing/public/public.html • G -> ZZ • eeμμ • μμ μμ • eeee • eejj • Looserequirement for e andmuons • Trigger e orμ: pT > 20 GeV • Relaxedlepton (e, μ) + 2 jets (pT > 10 GeV) or 2 relaxedlepton • Estimatethebgfromsidebands Pedro Mercadante

  19. Results • Modelindependentresults for Mx > 300 GeV • In theRandallSundrum framework leads to M > 491 GeV (k/Mpl = 0.1) Pedro Mercadante

  20. Di Muon(RandallSundrum) CDF arXiv:0811.0053 • 2 Muonchannel • Selection • 2 muons • pt > 30 GeV • eta < 1 • Bg • Drell Yan • Results • Spin2 (RS) mass > 921 GeV (k/Mpl = 0.1) • Spin 1 (Z´) mass > 1030 GeV • Spin 0 (sneutrino) mass > 810 GeV (λ*BR=0.01) Pedro Mercadante

  21. Di Electrons(RandallSundrum) http://www-cdf.fnal.gov/physics/exotic/r2a/20080306.dielectron_duke/pub25/duke.html • Selection • 2 electrons • pT> 25 GeV • eta < 2 • Bg • Drell Yan • Results • Spin 2 (RS) mass > 850 GeV (k/Mpl = 0.1) • Spin 1 (Z´) mass > 955 GeV • Similar studyfromDZero • RS Gravitonmass > 900 GeV (k/Mpl = 0.1) • 1 .1 fb-1, ee+γγsignal PRL 100, 091802 Pedro Mercadante

  22. Leptoquarks(lepton + quark signal) • Leptoquarkscarriesbothcolor charge andleptonnumber • Are present in severalmodels • Compositness, GUT, Superstring • Provides a clear signature • l+ jets • From FCNC suppression l+q shouldbeofsamegeneration Pedro Mercadante

  23. ThirdGeneration LQ D0 arXiv:0806.3527 • LQ -> tau b • 2 b jets, 2 taus • Preselection • 2 jets, pT> 20 GeV, eta < 2.5 • 1 muon, pT > 15, eta < 2 • 1 hadronictau (dependondecaymode) • 1 pT >15 GeV • pT >15 GeV • pT > 20 GeV > 2 tracks • Background • Multijets • top pairproduction • W/Z + jets • Diboson Pedro Mercadante

  24. Results NN for tauidentification NN for b identification Leptoquarkmass > 210 GeV Pedro Mercadante

  25. AcoplanarTopologyLeptoquarksandT-odd quarks D0 arXiv:0806.3527 • Jets + Missing ET • ET > 75 GeV • pT1, pT2 > 35 GeV • Angles • J1, ET > 90o • J, ET > 50o • J, ET < 150o • Lepton Veto • Backgrounds • W/Z + jets • Ttpair • WZ pair • Results • Optimization in ETand HT • LQ mass > 205 GeV • T-odd quark mass > 400 GeV Pedro Mercadante

  26. Conclusions • TheTevatron is ourbest machine atthepresent • Atthepresent no evidence for newphenomena is observed (data for 2-3 fb-1 ) • The data is beingwellunderstood • New data is beinganalyzed (3-4.5 fb-1 ) 4.5 fb-1 Sep 2008 • Publicwebpages: • http://www-cdf.fnal.gov/physics/exotic/exotic.html • http://www-d0.fnal.gov/d0_publications/d0_pubs_list_runII_bytopic.html#np Pedro Mercadante

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