SUSY searches with ATLAS What did we learn with few fb -1?

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1 SUSY searches with ATLAS What did we learn with few fb -? Iacopo Vivarelli Universität Freiburg I. Vivarelli - Marseille - 09 Feb 0 Wednesday, February 8, 0

2 Is the Standard Model enough? The Standard Model has accumulated more than 30 years of striking successes in particle physics experiments, but: a) The Higgs sector suffers from quadratically divergent loop corrections mainly from top (the so called hierarchy problem) b) Cosmological data call for a dark matter candidate: no such candidate is present in the SM c) No further unification between the EW and QCD possible Supersymmetry (SUSY) offers an elegant solution for a), which can simultaneously address b) and c) Wednesday, February 8, 0 I.Vivarelli - Marseille - 09 Feb 0

3 Supersymmetry (SUSY) SUSY is a spin symmetry that relates bosons and fermions In the Minimal Supersymmetric Extension of the Standard Model (MSSM): a new set of fields differing in spin by / w.r.t. the SM partners (hierarchy problem solved naturally ) Running of coupling constants above the EW scale modified: unification possible If R-parity conservation assumed, the Lightest Supersymmetric Particle (LSP) is stable: natural Dark Matter candidate Mix into neutralinos and charginos R-parity = (-) 3(B-L) + s - for sparticles for particles Wednesday, February 8, 0 I.Vivarelli - Marseille - 09 Feb 0 3

4 Minimal SUSY extension of SM (MSSM) If SUSY is unbroken, Msparticle = Mparticle. Since sparticles are not yet observed, SUSY must be (softly) broken: LSUSY = LSUSY conserving + LSUSY soft breaking MSSM parameters: higgs doublets needed 5 Higgs bosons A total of 4 parameters. Constraints needed: SUSY conserving sector 3 coupling constants for SU(3) xsu()su() 4 Yukawa couplings per generation SUSY breaking sector 5 3x3 hermitian mass matrices (one per EW multiplet) 3 complex 3x3 matrices (Higgs trilinear couplings to sfermions) 3 mass terms for the Higgs sector + additional off-diagonal terms Higgs VEV expectation angle β Bottom up: separate lepton number conservation, FCNC suppression, CP violation constrain the MSSM parameters Top-down: Precise assumptions are made on the way SUSY is broken: msugra/cmssm GMSB AMSB Wednesday, February 8, 0 I.Vivarelli - Marseille - 09 Feb 0 4

5 (R-parity) conserving SUSY phenomenology Missing ET is the main signature (although not unique) General R-parity signatures: The LSP (typically χ 0 or ν in msugra) is stable and weakly interacting (dark matter candidate) large missing transverse momentum squarks and gluinos produced in pp collision large particle multiplicity typically produced in the decay. Large jet multiplicities and/or lepton produced in large regions of the parameter space (although not mandatory, e.g. pp q q qq χ 0 χ 0 ) Wednesday, February 8, 0 I.Vivarelli - Marseille - 09 Feb 0 5

6 Experimental setup 6 Wednesday, February 8, 0

7 Wednesday, February 8, 0 I.Vivarelli - Marseille - 09 Feb 0 7

8 Mt. Blanc Saleve Lac Leman Geneve Airport Wednesday, February 8, 0 I.Vivarelli - Marseille - 09 Feb 0 7

9 Mt. Blanc Saleve Lac Leman Geneve Airport Wednesday, February 8, 0 I.Vivarelli - Marseille - 09 Feb 0 7

10 Mt. Blanc Saleve Lac Leman Geneve Airport Wednesday, February 8, 0 I.Vivarelli - Marseille - 09 Feb 0 7

analysis so far use - fb -. results being updated for the winter conferences Large luminosity means large pileup.

11 LHC - performance of the machine About 5 fb - collected per experiment in 0 Most of which with more than 99% of the detectors operational (talking about millions of channels that need to be maintained and calibrated) Most of the analysis so far use - fb -. results being updated for the winter conferences Large luminosity means large pileup. Analysing data while implementing pileup suppression strategies fb - fb - Wednesday, February 8, 0 I.Vivarelli - Marseille - 09 Feb 0 8

12 The detector Wednesday, February 8, 0 I.Vivarelli - Marseille - 09 Feb 0 9

13 ATLAS in a nutshell From inside out: ID made up of three different detectors (Pixel, SCT, TRT): High resolution tracking down to PT > o(00) MeV, η <.5 EM calorimeter - two sections covering up to η 3.. High resolution on e/γ objects. HAD calorimeter - 3 sections covering up to η 5 Good containment, good resolution for jet measurement Muon system (4 different technologies) covering up to η =.7 Magnetic field: one solenoid surrounding the ID (T), three toroids (muon spectrometer - 4T peak) Wednesday, February 8, 0 I.Vivarelli - SUSY searches with ATLAS - Paris - March 3st 0 0

Jet measurement C o n s t a n t i m p r o v

14 Jet measurement C o n s t a n t i m p r o v e m e n t o n j e t measurement Jet energy scale known at few percent... and the in-situ measurements (gamma + jet balancing) not yet in the game... Last year Wednesday, February 8, 0 I.Vivarelli - Marseille - 09 Feb 0

15 Missing transverse energy Missing ET reconstructed from the vectorial sum of all final state objects (including non-associated clusters). Dedicated calibration for each type of object Fake MET Real MET Wednesday, February 8, 0 I.Vivarelli - Marseille - 09 Feb 0

16 The Standard Model in one slide Wednesday, February 8, 0 I.Vivarelli - Marseille - 09 Feb 0 3

17 ATLAS in a nutshell (II) A dileptonic ttbar event candidate Wednesday, February 8, 0 I.Vivarelli - SUSY searches with ATLAS - Paris - March 3st 0 4

18 An ATLAS event Wednesday, February 8, 0 I.Vivarelli - Marseille - 09 Feb 0 5

19 SUSY searches 6 Wednesday, February 8, 0

20 What are we sensitive to? LHC is a pp machine produce gluino and squarks with strong interaction size cross sections If squarks and gluinos are not accessible, then direct gauginos might be the only SUSY production (with weak interaction size cross section - order of magnitudes lower) - fb - Essentially sensitive to strong production set direct limits on q and g masses Need higher lumi for gauginos (one of the targets of the 5 fb - analysis) Wednesday, February 8, 0 I.Vivarelli - Marseille - 09 Feb 0 7

21 What we are typically doing Heavy sparticles produced in the primary collision They decay into lighter objects, emitting (high) PT jets and possibly other objects (leptons, photons) and MET (LSP) A typical SUSY event will have large MET and large HT Useful variables:!m " M!M H T = jets p jets T (+ l p l T +...) M eff = E miss T + H T Wednesday, February 8, 0 I.Vivarelli - Marseille - 09 Feb 0 8

What we are typically doing Heavy sparticles produced in the primary collision They decay into lighter objects, emitting (high) PT jets and possibly other objects (leptons, photons) and MET (LSP) A

22 What we are typically doing Heavy sparticles produced in the primary collision They decay into lighter objects, emitting (high) PT jets and possibly other objects (leptons, photons) and MET (LSP) A typical SUSY event will have large MET and large HT Useful variables:!m " M!M H T = jets p jets T (+ l p l T +...) M eff = E miss T + H T Wednesday, February 8, 0 I.Vivarelli - Marseille - 09 Feb 0 8

23 List all analysis A wide research program trying to cover all possible SUSY configurations 0-lepton, jets, MET all, simple and more complex gluino-squarks decay chains -lepton, jets, MET More complex decay chains of the g, q (involving, e.g., charginos) -leptons Long decay chains (also direct gaugino production) multilepton Long decay chains, very low background, very low signal acceptance b-jets Third generation squark production photons Mainly GMSB (Gauge Mediated Supersymmetry Breaking) taus Mainly GMSB, but also high tan β msugra Analysis in blue discussed in some detail in the following Wednesday, February 8, 0 I.Vivarelli - Marseille - 09 Feb 0 9

24 0-lepton analysis (ATLAS) Depending on the SUSY mass hierarchy, different production processes favoured ( g g, g q, q q ) Signal regions optimised to maximise sensitivity to different production processes m q m g =m q m g Wednesday, February 8, 0 I.Vivarelli - Marseille - 09 Feb 0 0

25 0-lepton analysis (ATLAS) Depending on the SUSY mass hierarchy, different production processes favoured ( g g, g q, q q ) m q Signal regions optimised to maximise sensitivity to different production processes 4 jets g g g q q χ 0 q m g =m q m g Wednesday, February 8, 0 I.Vivarelli - Marseille - 09 Feb 0 0

26 0-lepton analysis (ATLAS) Depending on the SUSY mass hierarchy, different production processes favoured ( g g, g q, q q ) m q Signal regions optimised to maximise sensitivity to different production processes 4 jets m g =m q g g jets q q m g g q q q χ 0 q χ 0 q Wednesday, February 8, 0 I.Vivarelli - Marseille - 09 Feb 0 0

27 0-lepton analysis (ATLAS) Depending on the SUSY mass hierarchy, different production processes favoured ( g g, g q, q q ) m q Signal regions optimised to maximise sensitivity to different production processes 4 jets m g =m q g g 3 jets g q jets q q m g g q q q χ 0 q χ 0 q Wednesday, February 8, 0 I.Vivarelli - Marseille - 09 Feb 0 0

0-lepton analysis (ATLAS) Depending on the SUSY mass hierarchy, different production processes favoured ( g g, g q, q q ) Signal regions optimised to maximise sensitivity to different production

28 0-lepton analysis (ATLAS) Depending on the SUSY mass hierarchy, different production processes favoured ( g g, g q, q q ) Signal regions optimised to maximise sensitivity to different production processes m q 4 jets 3 jets Trigger requirements Channel definition m g =m q jets m g Reduce QCD Enhance signal m eff = I.Vivarelli - Marseille - 09 Feb 0 n i= p jet i T + ET miss Wednesday, February 8, 0

29 0-lepton analysis (ATLAS) As much background information as possible extracted from the data: One example: Z νν is the dominant component of the total Z background Estimation done in CR (in both cases replacing the boson with MET): γ+jets events (use robustness of ratio between photon and Z production cross section) Z ( ee,μμ) + jets Entries / 00 GeV L dt ~.04 fb - Three Jet Channel Data 0 ( s=7 TeV) +jets ATLAS Preliminary Entries / 00 GeV L dt ~.04 fb - Three Jet Channel Data 0 ( s = 7 TeV) SM Total QCD multijet W+jets Z+jets tt and single top SM + SU(660,40,0,0) ATLAS Preliminary DATA/MC m eff [GeV] DATA / MC [GeV] m eff Wednesday, February 8, 0 I.Vivarelli - Marseille - 09 Feb 0

30 Entries / 00 GeV 6 0 Data 0 ( s = 7 TeV) - SM Total L dt ~.04 fb QCD multijet 5 0 W+jets Dijet Channel Z+jets tt and single top SM + SU(660,40,0,0) ATLAS Preliminary Entries / 00 GeV L dt ~.04 fb - Three Jet Channel Data 0 ( s = 7 TeV) SM Total QCD multijet W+jets Z+jets tt and single top SM + SU(660,40,0,0) ATLAS Preliminary DATA / MC [GeV] m eff DATA / MC [GeV] m eff Entries / 00 GeV 5 0 Data 0 ( s = 7 TeV) - SM Total L dt ~.04 fb QCD multijet 4 0 W+jets Four Jet Channel Z+jets 3 0 tt and single top SM + SU(660,40,0,0) Entries / 50 GeV L dt ~.04 fb - Four Jet High Mass Channel Data 0 ( s = 7 TeV) SM Total QCD multijet W+jets Z+jets tt and single top SM + SU(660,40,0,0) DATA / MC ATLAS Preliminary [GeV] Wednesday, February 8, 0 m eff DATA / MC ATLAS Preliminary [GeV] m eff 3

0-lepton analysis (ATLAS) excluded σx acc x eff (fb) 4 30 477 3 7 No discrepancy with respect to SM predictions.

31 0-lepton analysis (ATLAS) excluded σx acc x eff (fb) No discrepancy with respect to SM predictions. The result is interpreted as a 95% CL exclusion limit on effective cross sections Analysis giving best expected limit used in each point. Wednesday, February 8, 0 I.Vivarelli - Marseille - 09 Feb 0 4

0-lepton analysis (ATLAS) Simplified model (pheno MSSM) interpretation: LSP mass set to 0, all other sparticles (except gluinos and st and nd gen quarks) set to 5 TeV g qq and q qχ 0 with BR 00%

32 0-lepton analysis (ATLAS) Simplified model (pheno MSSM) interpretation: LSP mass set to 0, all other sparticles (except gluinos and st and nd gen quarks) set to 5 TeV g qq and q qχ 0 with BR 00% Limit as a function of the squark and gluino mass msugra limit (m0, m/) [GeV] m / 600 MSUGRA/CMSSM: tan = 0, A = 0, µ>0 0 ATLAS Preliminary int L - =.04 fb, s=7 TeV ± LEP D0 ~ g, ~ q, tan =3, µ<0,. fb CDF ~ g, ~ q, tan =5, µ<0, fb Theoretically excluded lepton 0 combined CL s observed 95% C.L. limit CL s median expected limit exp. limit 68%, 99% CL Reference point 00 data PCL 95% C.L. limit 500 ~ q (400) ~ g (00) 400 ~ q (000) ~ g (000) 300 ~ g (800) ~ q (600) 00 ~ g (600) Wednesday, February 8, 0 I.Vivarelli - Marseille - 09 Feb [GeV] m 0 5

33 Limits A lot of model-dependent limits obtained for strong production Wednesday, February 8, 0 I.Vivarelli - Marseille - 09 Feb 0 6

Limits A lot of model-dependent limits obtained for strong production [GeV] m LSP 00 000 800 600 400 00 CMS Preliminary, s = 7 TeV, L =.

300 tan$ = 0, A = 0, µ > 0 95% CL upper limit on σ [pb] SS Dilepton CMS Preliminary 700 NLO observed limit NLO expected OS Dilepton limit 600 00 NLO observed limit tan" = 0, Multi-Lepton A = 0, µ > 0

fb 00 400 600 800 000 00 400 LM6 m [GeV] g ~ 0 00 400 600 800 000 g 300 ~ (750) 00 CMS Preliminary 700 600 500 400 0 Limits 00 = LSP $ % LM $ # = LSP CMS Preliminary '& = LSP q ~ (50)GeV 95% C.L. Limits: Jets+MHT 0 MT 500 000 500 - Razor m(0.

98 fb - CDF g~, ~ q, tan"=5, µ<0, fb - D0 g~, ~ q, tan"=3, µ<0,.

34 Limits A lot of model-dependent limits obtained for strong production [GeV] m LSP CMS Preliminary, s = 7 TeV, L =. fb int pp ~ g ~ g, ~ g j + χ, χ 0 Z + LSP m( ~ q) >> m( ~ g) prod 500 σ = σ NLO-QCD prod σ = 3 σ NLO-QCD prod σ = /3 σ NLO-QCD ) (GeV/c m / ) (GeV/c m / (GeV) m / 00 Limits tan$ = 0, A = 0, µ > 0 95% CL upper limit on σ [pb] SS Dilepton CMS Preliminary 700 NLO observed limit NLO expected OS Dilepton limit NLO observed limit tan" = 0, Multi-Lepton A = 0, µ > (. fb LM6 m [GeV] g ~ g 300 ~ (750) 00 CMS Preliminary Limits 00 = LSP $ % LM $ # = LSP CMS Preliminary '& = LSP q ~ (50)GeV 95% C.L. Limits: Jets+MHT 0 MT Razor m(0.8 0 (GeV) fb ) Lepton q~ (500)GeV q~ (50)GeV 0 q~ (000)GeV q ~ (750)GeV q~ (750) q ~ (500) q~(750)gev q~(500)gev q~ (000) q~(000)gev LM3 q~(50)gev =. fb, s = 7 TeV,!! T L dt = 0.98 fb - CDF g~, ~ q, tan"=5, µ<0, fb - D0 g~, ~ q, tan"=3, µ<0,. fb ± LEP $ # ~ ± LEP l (GeV/c ) L int LS Observed Limit, CL s LS Median Expected Limit LS Expected Limit ± % 00 LS Observed Limit, FC - ) - m 0 s = 7 TeV tan! = 0, A = 0, µ > 0 0 g ~ (000)GeV g ~ (000) m 0 g ~ (500) CDF g ~,(500)GeV ~ q, tan!=5, µ<0 D0 g ~, ~ q, tan!=3, µ<0 ± LEP # " g ~ ~ (50)GeV ± LEP l s = 7 TeV, # Ldt " fb CDF - - g~, q ~, tan$=5, µ<0 D0 g~, ~ q, tan$=3, µ<0 g ~ (750)GeV ± LEP & % ~ ± LEP l g ~ (50)GeV (500)GeV g ~ (000)GeV g ~ (750)GeV g ~ (500)GeV (GeV/c ) Wednesday, February 8, 0 I.Vivarelli - Marseille - 09 Feb 0 6

35 In short... No sign of SUSY, yet. Where do we stand? LEP LHC Tevatron If gluinos and squarks (st and nd gen) exist, they have M > TeV Wednesday, February 8, 0 I.Vivarelli - Marseille - 09 Feb 0 7

36 Is then SUSY dead? No! (pretty consistent theoretical view on the subject) Gluinos and st and nd generation squarks can be heavy, provided that the superpartners of the heavy fermions are relatively light (still natural hierarchy) Higgsinos should also be light LHC N. Arkani-Ahmed (CERN Workshop, 3-Oct ) L. Hall (LBL Workshop, -Oct)... and this is not yet covered by LHC I.Vivarelli - Marseille - 09 Feb 0 Wednesday, February 8, 0 8

37 3 rd generation production The third generation squarks are special Mixing between L and R component of squarks proportional to the fermion partner mass large mixing for 3rd generation squarks generally expected to be the lightest squarks Previous limits on squark masses do not apply to sbottom and stop The stop directly counter-balance quadratically divergent top loop corrections to the Higgs mass Wednesday, February 8, 0 I.Vivarelli - Marseille - 09 Feb 0 9

3 rd generation (gluino mediated sbottom) stop, sbottom can be produced via gluino decay or directly in pairs Expected to produce abundance of b-jets in the final state

38 3 rd generation (gluino mediated sbottom) stop, sbottom can be produced via gluino decay or directly in pairs Expected to produce abundance of b-jets in the final state Existing analysis mainly probing gluino mediated production They set limits mainly on the gluino mass g b b b χ 0 Wednesday, February 8, 0 I.Vivarelli - Marseille - 09 Feb 0 30

3 rd generation (gluino mediated sbottom) Interpretation: g bb with BR: 00%, b χ 0 b with BR: 00% On-shell sbottom production: m g > m b (left), and all other sparticles with large mass

39 3 rd generation (gluino mediated sbottom) Interpretation: g bb with BR: 00%, b χ 0 b with BR: 00% On-shell sbottom production: m g > m b (left), and all other sparticles with large mass (beside LSP) Off-shell sbottom production (fixed sbottom mass at TeV) but still all other sparticles with even larger masses Wednesday, February 8, 0 I.Vivarelli - Marseille - 09 Feb 0 3

MET, large MT Main background: SM ttbar Results consistent with the Standard

40 3 rd generation (gluino mediated stop) stop, sbottom can be produced via gluino decay or directly in pairs Selection: lepton, 4 jets ( b-tagged), large MET, large MT Main background: SM ttbar Results consistent with the Standard Model g t t jjb χ 0 t lνb Wednesday, February 8, 0 I.Vivarelli - Marseille - 09 Feb 0 3

Some non-significant excess observed above the Standard Model predictions g

41 3 rd generation (gluino mediated stop) Signal interpretation similar to the sbottom (on- and off-shell stop-mediated three body decay of the gluino) Some non-significant excess observed above the Standard Model predictions g t t jjb χ 0 t lνb Wednesday, February 8, 0 I.Vivarelli - Marseille - 09 Feb 0 33

42 Getting closer to the stop... With fb - we are sensitive to sbottom pair production (same cross section as stop, easier to separate from the background) b-jets (30, 50 GeV) and large MET (30 GeV) Make use of the contransverse mass b χ 0 b... corrected for the boost of the objects Kinematical end point for the top at 38 GeV Three different cuts on MCT to maximize sensitivity in the m b-mneutralino plane Data driven top estimate using a -lepton control region Wednesday, February 8, 0 I.Vivarelli - Marseille - 09 Feb 0 34

43 Getting closer to the stop... Z+hf background estimated in a -lepton control region on the Z peak top contamination measured in the sidebands of the Mll distribution Wednesday, February 8, 0 I.Vivarelli - Marseille - 09 Feb 0 35

for the interpretation of the result: b b χ 0 with BR 00% Tevatron

44 Getting closer to the stop... Final MCT distribution consistent with the SM predictions Model for the interpretation of the result: b b χ 0 with BR 00% Tevatron limit significantly extended Stay tuned for the stop... Wednesday, February 8, 0 I.Vivarelli - Marseille - 09 Feb 0 36

Status: new Higgs limits exclude a Higgs boson with mass above ~30 GeV or

45 Before concluding... The data from Higgs boson searches (will) tell us a lot about SUSY. Status: new Higgs limits exclude a Higgs boson with mass above ~30 GeV or below 5 GeV. An excess is observed at 4 GeV in CMS (6 GeV in ATLAS):.5 σ ATLAS.9 σ CMS Wednesday, February 8, 0 I.Vivarelli - Marseille - 09 Feb 0 37

Consequences for SUSY Let s assume the Higgs boson exists and it has a mass of 5 GeV: Then the two stop are either both moderately heavy (multi-tev) or their mass splitting is very large (and

46 Consequences for SUSY Let s assume the Higgs boson exists and it has a mass of 5 GeV: Then the two stop are either both moderately heavy (multi-tev) or their mass splitting is very large (and anyhow, mt > 500 GeV) In general, SUSY spectrum pushed at high energies, perhaps not accessible by the 7 TeV LHC arxiv:.3564v arxiv:.703v Wednesday, February 8, 0 I.Vivarelli - Marseille - 09 Feb 0 38

47 Summary LHC has opened a new era in the search for Supersymmetry No SUSY yet, but: The detector and the machine are working well, this is only the beginning. The analysis strategies are solid and constantly improved So far mostly sensitive to strong production of gluinos and st and nd generation squarks, becoming sensitive to direct gaugino and 3rd generation production Higgs searches putting already quite strong constraints on SUSY New CMS energy of LHC will significantly increase the sensitivity Wednesday, February 8, 0 I.Vivarelli - Marseille - 09 Feb 0 39

48 BACKUP 40 Wednesday, February 8, 0

Strong production with leptons The 0-lepton analysis is very powerful, but it does not cover at best

strategy involving leptons baseline -lepton analysis being reviewed: soft lepton analysis (changing

lepton analysis demonstrated to have sensitivity in, e.g.

49 Strong production with leptons The 0-lepton analysis is very powerful, but it does not cover at best all possible scenarios Longer gluino decay chains ( g qq qq χ ± qqw χ0 ) better addressed by strategy involving leptons baseline -lepton analysis being reviewed: soft lepton analysis (changing trigger strategy) brings sensitivity close to the diagonal re-optimization of the signal regions Two lepton analysis demonstrated to have sensitivity in, e.g. GMSB Joined effort desirable taus soon included Z+MET analysis close to release results Wednesday, February 8, 0 I.Vivarelli - Marseille - 09 Feb 0 4

via gluino decay But quickly becoming sensitive to the third generation squark direct

50 Strong production - 3 rd generation A particularly hot topic is the search for third generation squarks Searches performed so far mostly sensitive to sbottom and stop produced via gluino decay But quickly becoming sensitive to the third generation squark direct production directly attacking the natural spectrum Wednesday, February 8, 0 I.Vivarelli - Marseille - 09 Feb 0 4

51 Systematic uncertainties Systematic uncertainties are reduced by the use of the transfer factors Jet energy scale and resolution uncertainties derived using 00 data Additional, conservative, uncertainties due to pileup considered (typical effect on TF ~5%) Monte Carlo modelling uncertainties addressed by comparing transfer factor obtained with, e.g., ALPGEN or and varying renormalisation and factorisation scales (~5%) Depending on the CR: CR available statistics, lepton identification, b-tagging, etc. considered, typically with a smaller impact. Wednesday, February 8, 0 I.Vivarelli - Marseille - 09 Feb 0 43

52 QCD background estimation QCD pseudo-events obtained by smearing low ET significance events with a jet response function. Validation: QCD prediction from pseudoevents compared to data in events where Δϕmin (jet,et miss ) < 0.4 QCD multi-jet events have large MET because of jet mismeasurement or heavy flavours leptonic decays. In both cases MET tends to align with one of the jets Entries / 00 GeV DATA / MC L dt ~.04 fb - Three Jet Channel Data 0 ( s = 7 TeV) SM Total QCD multijet W+jets Z+jets tt and single top SM + SU(660,40,0,0) ATLAS Preliminary [GeV] m eff Wednesday, February 8, 0 I.Vivarelli - Marseille - 09 Feb 0 44

53 Minimal SUSY extension of SM (MSSM) If SUSY is unbroken, Msparticle = Mparticle. Since sparticles are not yet observed, SUSY must be (softly) broken: LSUSY = LSUSY conserving + LSUSY soft breaking MSSM parameters: higgs doublets needed 5 Higgs bosons A total of 4 parameters. Constraints needed: SUSY conserving sector 3 coupling constants for SU(3) xsu()su() 4 Yukawa couplings per generation SUSY breaking sector 5 3x3 hermitian mass matrices (one per EW multiplet) 3 complex 3x3 matrices (Higgs trilinear couplings to sfermions) 3 mass terms for the Higgs sector + additional off-diagonal terms Higgs VEV expectation angle β Bottom up: separate lepton number conservation, FCNC suppression, CP violation constrain the MSSM parameters Top-down: Precise assumptions are made on the way SUSY is broken: msugra/cmssm GMSB AMSB Wednesday, February 8, 0 I.Vivarelli - Marseille - 09 Feb 0 45

54 Analysis strategy Main expected SM background: W/Z + jets, top production, QCD multi-jet For each background, for each signal region, one or more dedicated control regions (CR) Background determination done with a combined fit to all CRs (mutual background contamination in CR and correlations automatically taken into account) Transfer factors (TF) from each background process CR to the SR are computed using a mix of data-driven and Monte Carlo driven techniques. Wednesday, February 8, 0 I.Vivarelli - Marseille - 09 Feb 0 46

55 W and top control regions Two control regions defined in events containing one additional lepton (additional selection 30 GeV < MT < 00 GeV): Applying a b-tag veto a W control region is obtained. Applying a b-tag requirement a top control region is obtained. Entries / 00 GeV 5 0 Data 0 ( s = 7 TeV) - SM Total L dt ~.04 fb QCD multijet 4 0 W+jets Three Jet Channel Z+jets 3 0 tt and single top SM + SU(660,40,0,0) Entries / 00 GeV L dt ~.04 fb - Three Jet Channel Data 0 ( s = 7 TeV) SM Total QCD multijet W+jets Z+jets tt and single top SM + SU(660,40,0,0) 0 ATLAS Preliminary 0 ATLAS Preliminary 0 0 DATA / MC [GeV] I.Vivarelli - Marseille - 09 Feb 0 Wednesday, February 8, 0 m eff DATA / MC [GeV] m eff 47

56 Result interpretation () [GeV] m / MSUGRA/CMSSM: tan = 0, A = 0, µ>0 0 ATLAS Preliminary int L ~ q (600) =.04 fb, s=7 TeV ± LEP D0 ~ g, ~ q, tan =3, µ<0,. fb CDF ~ g, ~ q, tan =5, µ<0, fb Theoretically excluded ~ q (000) - ~ q (400) lepton 0 combined CL s observed 95% C.L. limit CL s median expected limit exp. limit 68%, 99% CL Reference point 00 data PCL 95% C.L. limit ~ g (600) ~ g (00) ~ g (000) ~ g (800) [GeV] m 0 Results interpreted in msugra/cmssm (A0 = 0, tanβ = 0, μ>0) Limit in large m0 region p r o fi t s f r o m t h e introduction of signal regions with large jet multiplicities. E q u a l s q u a r k - g l u i n o masses excluded below 980 GeV Wednesday, February 8, 0 I.Vivarelli - Marseille - 09 Feb 0 48

57 Multilepton analysis (CMS) Background from fake leptons: e/mu: Compute probability that an isolated track fakes a lepton in QCD events estimate background from a -lepton sample tau: use sidebands of isolation distribution Z µ µ µ µ µ Background from asymmetric conversions: Arbitrary Units Estimated comparing lll to llγ at the Z peak CMS Preliminary - s=7 TeV, L =. fb int tt Z! ll Relative Isolation top and di-boson background estimated using MC (validated in CR) Events/5 GeV/c CMS Preliminary s = 7 TeV, L =. fb int (Z/!*) " ll! VV tt (Z/!*)+Jet M(µ µ 00 - µ) [GeV/c 50 ] Wednesday, February 8, 0 I.Vivarelli - Marseille - 09 Feb 0 49

58 Multilepton analysis (CMS) 0 0 CMS Preliminary tt WZ/ZZ ttw / ttz / WWW Data-driven Bkg Uncertainties - s =7 TeV, L =. fb int 3 leptons: 3(e/µ ) channels 0-0 CMS Preliminary 0 tt WZ/ZZ ttw / ttz / WWW Data-driven Bkg Uncertainties - s =7 TeV, L =. fb int 4 leptons: 4(e/µ ) channels 0τ HT>00 DY0 HT<00 DY0 HT>00 DY0 HT<00 DY0 HT>00 DY HT>00 DY HT<00 DY HT<00 DY HT>00 DY HT>00 DY HT<00 DY HT<00 DY -3 0 HT>00 HT>00 HT<00 HT<00 HT>00 HT>00 HT<00 HT< CMS Preliminary HT>00 DY0 tt WZ/ZZ ttw / ttz / WWW Data-driven Bkg Uncertainties HT<00 DY0 HT>00 DY0 CMS Preliminary HT<00 DY0 HT>00 DY HT>00 DY - s =7 TeV, L =. fb 3 leptons: (e/µ)+! channels int HT<00 DY - HT<00 DY HT>00 DY HT>00 DY HT<00 DY HT<00 DY s =7 TeV, L =. fb 3 leptons: (e/µ)+! channels int 0 tt WZ/ZZ CMS Preliminary HT>00 ttw / ttz / WWW Data-driven Bkg Uncertainties HT>00 CMS Preliminary HT<00 HT<00 - s =7 TeV, L =. fb 4 leptons: 3(e/µ)+! channels int HT>00 - HT>00 HT<00 HT<00 s =7 TeV, L =. fb 4 leptons: (e/µ)+! channels int τ 4 0 tt WZ/ZZ ttw / ttz / WWW Data-driven Bkg Uncertainties 0 0 tt WZ/ZZ ttw / ttz / WWW Data-driven Bkg Uncertainties τ HT>00 DY0 HT<00 DY0 HT>00 DY0 HT<00 DY0 HT>00 DY - 0 HT>00 HT>00 HT>00 DY HT<00 HT<00 HT<00 DY I.Vivarelli - Marseille - 09 Feb 0 HT>00HT<00 HT>00 DY HT<00HT>00 HT<00 DY HT>00 DY HT<00 DY 50 HT<00 DY Wednesday, February 8, 0

59 tan β = 40 SUSY with b-jets SUSY with alpha_t [GeV] m / CMS Preliminary tan! = 40, A 0 q ~ (50)GeV = -500 GeV, µ > 0 - s = 7 TeV, L =. fb int Observed Limit g ~ (500)GeV Expected Limit ± " g ~ (50)GeV (GeV) m / 600 q~(500)gev q~(50)gev - CMS,.4 fb, 95% CL limits: s = 7 TeV Observed Limit (NLO), CL s Median Expected Limit ± " g ~ (500)GeV g ~ (50)GeV 400 q ~ (000)GeV g ~ (000)GeV 400 q~(000)gev tan! = 40, A = -500 GeV, µ > 0 0 g ~ (000)GeV 300 q ~ (750)GeV g ~ (750)GeV g ~ (750)GeV 00 g ~ (500)GeV 00 q~(750)gev g ~ (500)GeV m 0 [GeV] m 0 (GeV) Wednesday, February 8, 0 I.Vivarelli - Marseille - 09 Feb 0 5

60 Dark matter indirect results Wednesday, February 8, 0 I.Vivarelli - Marseille - 09 Feb 0 5

Multilepton analysis (CMS) A completely different analysis: focus on 3-lepton and >= 4 lepton signatures: Sensitive to R-parity conserving SUSY with many-steps gluino-squark decay and/or sleptons in

61 Multilepton analysis (CMS) A completely different analysis: focus on 3-lepton and >= 4 lepton signatures: Sensitive to R-parity conserving SUSY with many-steps gluino-squark decay and/or sleptons in the decay chain. MET expected in the final state Sensitive to R-parity violating SUSY no MET in final state Reminder H T = jets P T Very clean in principle However, need to be careful with fake leptons and (internal and non) photon conversions Wednesday, February 8, 0 I.Vivarelli - Marseille - 09 Feb 0 53

62 Multilepton analysis (CMS) 0 0 CMS Preliminary tt WZ/ZZ ttw / ttz / WWW Data-driven Bkg Uncertainties - s =7 TeV, L =. fb int 3 leptons: 3(e/µ ) channels 0-0 CMS Preliminary 0 tt WZ/ZZ ttw / ttz / WWW Data-driven Bkg Uncertainties - s =7 TeV, L =. fb int 4 leptons: 4(e/µ ) channels 0τ HT>00 DY0 HT<00 DY0 HT>00 DY0 HT<00 DY0 HT>00 DY HT>00 DY HT<00 DY HT<00 DY HT>00 DY HT>00 DY HT<00 DY HT<00 DY -3 0 HT>00 HT>00 HT<00 HT<00 HT>00 HT>00 HT<00 HT< CMS Preliminary HT>00 DY0 tt WZ/ZZ ttw / ttz / WWW Data-driven Bkg Uncertainties HT<00 DY0 HT>00 DY0 CMS Preliminary HT<00 DY0 HT>00 DY HT>00 DY - s =7 TeV, L =. fb 3 leptons: (e/µ)+! channels int HT<00 DY - HT<00 DY HT>00 DY HT>00 DY HT<00 DY HT<00 DY s =7 TeV, L =. fb 3 leptons: (e/µ)+! channels int 0 tt WZ/ZZ CMS Preliminary HT>00 ttw / ttz / WWW Data-driven Bkg Uncertainties HT>00 CMS Preliminary HT<00 HT<00 - s =7 TeV, L =. fb 4 leptons: 3(e/µ)+! channels int HT>00 - HT>00 HT<00 HT<00 s =7 TeV, L =. fb 4 leptons: (e/µ)+! channels int τ 4 0 tt WZ/ZZ ttw / ttz / WWW Data-driven Bkg Uncertainties 0 0 tt WZ/ZZ ttw / ttz / WWW Data-driven Bkg Uncertainties τ HT>00 DY0 HT<00 DY0 HT>00 DY0 HT<00 DY0 HT>00 DY - 0 HT>00 HT>00 HT>00 DY HT<00 HT<00 HT<00 DY I.Vivarelli - Marseille - 09 Feb 0 HT>00HT<00 HT>00 DY HT<00HT>00 HT<00 DY HT>00 DY HT<00 DY 54 HT<00 DY Wednesday, February 8, 0

63 Multilepton analysis (CMS) Some excess present (especially in 4 leptons with taus), large trial factor. Result still consisted as SM. tan! = 3, A 0 = 0, µ > 0 Interpreted as a 95% CL limit in specific msugra scenarios CMS Preliminary - s = 7 TeV, L =. fb int CMS Preliminary - s = 7 TeV, L =. fb int ) (GeV/c m / % C.L. CLs Limits NLO observed NLO expected median NLO expected ±% NLO observed 00 q ~ (750)GeV CDF g~, q ~, tan!=5, µ<0 D0 g~, ~ q, tan!=3, µ<0 ± LEP $ # ~ ± LEP l D0 # ±, # 0 ) (GeV/c m / %$ = LSP 95% C.L. CLs Limits NLO observed NLO expected median NLO expected ±& q ~ (750)GeV CDF tan! = 0, A 0 g~, q ~, tan!=5, µ<0 D0 g~, ~ q, tan!=3, µ<0 ± LEP $ # LEP ~ ± l = 0, µ > 0 q~ (500)GeV 00 q~ (500)GeV tan! = 3, A 0 = 0, µ > m 0 (GeV/c ) m 0 (GeV/c ) Wednesday, February 8, 0 I.Vivarelli - Marseille - 09 Feb 0 55

SUSY searches with the ATLAS detector at the LHC

SUSY searches with the ATLAS detector at the LHC Iacopo Vivarelli Albert-Ludwigs Universität Freiburg 1 Is the Standard Model enough? The Standard Model has accumulated more than 30 years of striking successes