CDF D0 Supersymmetry at the Tevatron R. Demina University of Rochester

2 20 years of SUSY And still, no one is prettier… “We like the way she walks, We like the way she talks” but… God damn it, where is she?

3 Outline Data sets Tri-leptons Jets and missing energy –Straight up –With heavy flavor Gauge Mediated SUSY Breaking – photons with missing energy Long-lived particles Conclusions

4 Run II data taking Presented analyses are based on pre-shutdown data <200pb -1

5 SUSY production at Tevatron 200 pb -1 –10 13 collisions –80 chargino/ neutralino  (3l) events produced –800 squark/gluino events produced To control backgrounds searches based on “signatures”: 3 or more physics objects

6 Tri-leptons Chargino/neutralino production – three leptons and missing energy signature Main challenge - weak production  low cross sections –LEP limits are very restrictive Need extremely well controlled backgrounds 3e2e  33 2e2e ee(l) e  (l)  Leptonic branching are enhanced if sleptons are lighter than gauginos (l ) – isolated track = e,  

7 ee+lepton 2 Electrons: EM cluster+track match P T >12 (8) GeV |  |<1.1 (3.0) 1.Anti-Z –15<Mee<60 GeV –  (ee)<2.8 2.Anti-W  (e )+  –>=1hit in silicon or tighter electron likelihood 3.Anti tt –Veto jets with E T >80GeV 4.Anti-Drell Yan –Missing E T >20GeV –  (eMET)>0.4 Potential signal 175pb -1

8 ee+lepton 5.Lepton = isolated track: –P T >3GeV 6.Etmiss x PT(track)>250GeV  (signal)=2-3%

9 Tri-leptons Summary after all cuts: ChannelDataTotal SM background e e l10.27  0.42  0.02 e   0.37  0.18 e  l00.54  0.24  0.04   0.06  0.02 Add isolated track with P T >3 GeV

10 Combined tri-leptons Run 1 cross section limit much improved Soon will reach MSugra prediction (in the best scenario with low slepton masses)

11 Jets and missing energy Squarks and gluions: Strong production –larger cross section, –but really large instrumental backgrounds (2 orders of magnitude over SM processes) 4 events left 2.67 expected from SM sources (Z/W production) 17.1 event expected for M 0 =25,M 1/2 =100GeV 85 pb -1 2 jets E T >60 (50) GeV 30<  (jet,MET)<165 o Final cuts: Missing E T >175 GeV H T >275 GeV

12 Squarks and gluinos M 0 =25GeV; A 0 =0; tan  =3;  <0 M(gluino)>333GeV Run 1 – 310 GeV M(squark)>292GeV

13 B-jets and missing energy High tan(  ) scenario under study: sbottom is lighter than other squarks and gluino 4b-jets+missing energy >=3jets (E T >10 GeV) Missing E T >35 GeV 1 b-tag – events SM predicted - 4 observed 2 b-tags – events SM predicted - 1 observed

14  Met Gauge mediated SUSY breaking at scale  Gravitino – LSP NLSP (neutralino)   LSP Dominant SUSY mode:       185 pb -1 Signature – 2 photons, missing energy P T (photon)>20 GeV in |  |<1.1 1 event survived 2.5±0.5 expected from SM Missing E T >40 GeV

15 Long Live Particles! LSP – charged particle, or NLSP – charged particle (e.g. stop) with long decay time Signature – isolated track of a rather slow particle Use TOF system (CDF) BG prediction of 2.9 +/- 0.7 (stat) +/- 3.1 (sys), with 7 observed d

16 Conclusions Tevatron detectors produce solid physics results based on datasets of up to 185 pb -1 SUSY limits extended beyond run 1: –In trilepton signature –Missing energy and jets –Missing energy and b-jets –GMSB in diphoton final state New system (TOF) used to search for long lived particles