SUSY & Non SM Higgs Searches

Transcription

1 SUSY & Non SM Higgs Searches Mario Martínez-Pérez (IFAE-Barcelona)

2 Outline SUSY Squark/Gluino Searches Search for Chargino/Neutralino GMSB Scenario Non SM Higgs Searches Bs->μμ vs MSSM the LHC Final Remarks Not covered in this talk SUSY in ttbar decays RPV Searches.

3 Hierarchy Problem 2 2 From EWK to Planck scale? < H > = 74 GeV m O( 00 GeV ) H H f 2 2 λ f 2 2 ΔmH = [ 2ΛUV + 6m ln( ΛUV /m ) +...] 2 f f 6π Λ = 5 TeV if Λ UV M planck fine tuning in 0 Already a serious problem at 5 TeV scale (cancellation among top, gauge and Higgs loops) 30!! This kind of conspiracy has name in Physics relative contributions to Δ 2 M H (taken from C. Quigg, hep-ph/ ) SuperSymmetry?

4 SuperSymmetry in 30" Fermion/Boson symmetry Q fermion Q boson > = boson > = fermion Exact cancellation between fermion & boson loops for Higgs (cures the hierarchy problem) > > Double Spectra of Particles G G ~..will mix to form mass eigenstates.. Higgs sector with 2 doublets H U,H D h,h,a, H ±..SUSY must be broken.. model-dependent phenomenology

5 msugra (gravity mediated SUSY breaking) SUSY breaking (hidden sector) gravity MSSM (visible sector) L soft terms introduce huge number (up to 05) of new parameters Assuming unification of masses at GUT scale allows to reduce it to 5 m 0 : common scalar mass at GUT m /2 : the common gaugino mass at GUT Evolved back using RGE tanβ: <HU>/<HD> A 0 : common (scalar) 3 coupling Sign(μ): Higgs mass term

6 Typical msugra Mass Spectra. Squarks and Gluinos are heavy 2. mixing of third generation leads to light stop/sbottom and stau 0 χ 3. will be the LSP (stable if Rp conserved) 4. One higgs is very light ( < 35 GeV)

7 Inclusive Gluino/Squark Search background reduction Diboson σ(pb) gluino/squark production at the energy frontier Assuming R-parity conservation Signature: + jets E T Understanding of beam backgrounds Difficult multiple SM backgrounds Detector effects top and Z->νν+jets irreducible understanding of QCD & W/Z+jets M (GeV)

8 Squark/Gluino Searches msugra scenario A 0 = 0 μ < 0 tanβ = 5 (CDF), tanβ = 3 (D0) scan in M 0 M /2 plane stop pair production not considered and the squark masses are averaged over 4 (CDF) or 5 (D0) flavors Experiments (CDF & D0) carry out searches in different final states E T + N jet, N jet = cuts on Δφ(E T - jet) against QCD - jets veto against electrons and muons - optimization across the plane using E T, E jets T and H T jets E jet T

9 NEW Squark/Gluino Search.4 fb- 2 jets 3 jets (C) 4 jets -.4 fb events in.4 fb - DATA SM Expected 4 jets ±2 ±9 3 jets (A) 3 jets (B) 3 jets (C) harder cuts ± 6 ± ±7 ±44 25 ±2 ±8 2 jets 3 ± 2 ± 3 Good agreement with SM predictions

10 NEW squark/gluino masses M gluino > % CL For M = Msquark M > gluino % CL

11 Limits on msugra parameters Tevatron results extend the LEP excluded region (LEP indirect limits) at low values of M0 and M/2

12 NEW 0.96 fb- Squark Production (τ+jets+met) msugra scenario (enhanced in τ decay) A 0 0 = 2 M, tanβ = 5, μ < Jets + MET (similar to inclusive search) At least one τ (hadronic decay) optimization based on MET and JJTHT E T > 75 GeV, JJTH 2 events (SM :.7 ± 0.3 Translates into a limit on squark mass: T 0 > 325 GeV M ~q > 95% CL ) LEP LEP

13 NEW Stop Pair Production scenario with very light stop ~ t 45 cχ 0 < M( χ (00%) 0 ) < 90 GeV fb- Cuts optimized for different stop masses ET > 70 GeV, HT > 40 GeV Only 2 jets At least one c-tag No isolated leptons Cuts on Δφ, jet) & (E T Δφ(jet, jet) 66 events (SM : 64.2 ± 9.5)

14 NEW fb- Stable Stop reconstructed as high-pt muons MTOF = p 2 β MTOF = p 2 β μ p T > 40 GeV /c, η μ < < β < 0.9 M(t ~ ) > % CL (stable)

15 Chargino/Neutralino Multiple leptons in the final state three leptons + MET two like sign leptons Relative low σxbr(in leptons) but is clean σ(pb) SM background very much reduced Dominated by Drell-Yan, Z/W+γ and Dibosons Small contributions from ttbar and bbar Long list of tuned cuts to kill SM contributions msugra scenario with tanβ = 3, A M( χ 0 2 ) = M( χ = 0, μ ± no slepton mixing dependency on χ 0 > 0 ) = 2M( χ 0 2 and 0 ) χ ± M (GeV) decay Br( leptons) ee+track

16 Chargino/Neutralino trileptons SM expect. DATA NEW µµ+track ee+ track ± eµ+l 0.9 ± Like sign μμ.± 0.4 Run IIa + Run IIb.7 fb- Improved limits compared to LEP results in msugra scenarios with no slepton mixing heavy-squarks: maximal cross section 3l-max: enhanced leptonic decays large-m0: W/Z exchange dominates New observed limit: σxbr < 0. pb (rather flat in mass)

17 Chargino/Neutralino fb- trileptons µµ+l (low pt) ee+ track µ+ll e+ll LS leptons ee eµ µµ SM expect. 0.4 ± 0..0 ± ± ± 0.4 SM expect. 2.9 ± ± ± 0. DATA 3 0 DATA 4 8

18 GMSB (gauge mediated SUSY breaking) Snowmass p8 spectra SUSY breaking (hidden sector) Gauge Fields MSSM (visible sector) SUSY breaking at scale Λ (0-00 TeV) Mediated by Gauge Fields ( messengers ) Gravitino is very light (~ KeV) and the LSP Neutralino is NLSP (its lifetime not fixed) Λ = 00 TeV N M m m tanβ μ > 0 = = 2Λ = 5 ~ 0 χ G γ Rp conservation (2 NLSP in final state) γγ + E T + X (taken from N. Ghodbane et al., hep-ph/020233)

19 NEW γγ+met (GMSB). fb- E T 2 photons Δϕ(E > 60 GeV T (p γ T, jet) < 2.5 > 25 GeV, η γ <.) 3 events (SM :.6 ± 0.4) Λ > 92 95% CL M( χ 0 ) > 26 GeV,M( χ + ) > 23 GeV

20 NEW γγ+met & γγ+τ - 2 fb Search for γγ+e T, Signal sample Events/5 GeV CDF Run II Preliminary,.2 fb Data QCD + fake E T eγ events Non-Collision E T, [GeV] Signature-based search: Good agreement with SM predictions

21 t 0.6 fb- γ c t f r r x xi f ti c Delayed Photons (GMSB) E T a photon a jet (E Δϕ(E > 40 GeV T 2 ns < t jet T (p, jet) > γ c γ T > 35 GeV, η < 0 ns > 25 GeV, η jet vertex & cosmics rejection γ <.) < 2) 2 events (background :.3 ± 0.7) M( χ 0 ) > 0 95% CL (with τ χ 0 = 5 ns)

22 Electroweak Fits (indirect Higgs Mass constrains) H Measured top and W masses favor low values for M H (dangerously entering MSSM regime)

23 MSSM Higgs H,H U D h,h,a and H ± tanβ =< H U Tree level : > / < H M A D > and tanβ as parameters enhanced coupling to down - type fermions (low M A and high tanβ) MSSM Higgs production cross section boosted compared to SM at large tanβ At low masses σ(φ) 2σ(Α) Br(h bb) ~ 90%, Br(h ττ) ~ 0%

24 NEW φb(b)->bb b(b) 3 b-tagged jets in the final state Two variables for discrimination M M 2 diff (invariant mass two leading jets) M jet vertex + M jet2 vertex M jet3 vertex Data fitted to templates for flavor mixing 0.98 fb- observed limit within 2σ of expected

25 0.9 fb- φb(b)->bb b(b) Use doubled-tags in data to compute b-tag probability for a third jet 3 b-tagged sample then normalized to data outside signal region (separately for each H mass point) Validation using MC samples (relative contributions taken from ALPGEN) observed limit in good agreement with expected

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27 φ >ττ m vis = p vis τ + p vis τ 2 + p / T eτ,μτ channel CDF Preliminary fb- 2 tau candidates One hadronic or leptonic (CDF) decay One leptonic decay (opposite charge) (CDF: e,μ) (D0: μ) small excess in CDF eτ+μτ channel (<2σ effect) - Not observed in CDF eμ channel - D0 analysis in good agreement with SM eμ channel

28 φ >ττ fb-

29 SM prediction Br(B SUSY big enhancement (~ tan s ) B s μ + μ - NEW - μ + μ ~ 3.42 x 0 6 β) -9 2 fb CDF analysis: Can distinguish Bs from Bd μμ Using Neural Net to extract signal Improve sensitivity by including NN output and Mμμ in limit calculation Bs window 3 events Bd window 6 events No significant excess! Br(B s μμ)<5.8 95% CL Br(B d μμ)<.8 95%CL

30 Bs vs MSSM This measurement shows its potential to introduce strong constraints on MSSM

31 NEW Doubly Charged Higgs exotic extensions of Higgs sector with higher isospin multiplets. fb- 2 like-sign muons p t > 5 GeV η < 2 isolated Δϕ μμ < 2.5 Mμμ > 30 GeV A third muon 3 events (SM :3. ± 0.5) M(H M(H ±± L ±± R ) ) > 50 GeV > 26 GeV

32 NEW Fermiophobic Higgs in 2γ+X. fb- γγ data vs SM backg. 2 photons (p γ T > 25 GeV, η <.) background from γγ, γ + jet and jet γ + jet signal region q γγ > T 35 GeV 2D fits to templates of EM shower profiles (separation between photons and jets) ( σ CPS E ) control region q γγ < T 35 GeV Mh > 92 95% CL

33 Well. No significant excess compared to SM yet Tevatron will deliver a total of 6-7 fb- by the end of FY2009

34 LHC Summer s = 4 TeV p p ATLAS CMS See S. Bertolucci s talk on S5

35 SUSY Searches at the LHC σ(pb) M (GeV) Tevatron (squark/gluinos) The LHC is built to discover SUSY If it is there, we will find it relatively soon But do not underestimate the commissioning phase and the work needed to understand the SM backgrounds.

36 Very broad and strong program for SUSY searches at the Tevatron. No significant excess w.r.t SM yet.. Experiments have presented results with up to 2 fb- of data analyzed. Final Notes Tevatron will deliver up to 6-7 fb- of data by the end of FY2009. you name it.. LHC starts operations on summer 2008 with great potential for an early discovery. The next two years will be very exciting ( First SUSY discovery by LP 09?!)

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38 Backup Slides

39 Tevatron Chicago Booster s =.96 TeV p p CDF DØ Tevatron p source Main Injector (new)

40 Tevatron/CDF&D0 Tevatron: 3.2 fb- delivered CDF & DØ recording physics quality data with very high efficiency (~85%)

41 The Standard Model (i.e., the need for new physics) Who ordered 3 generations? Origin of Masses? What about Gravity? Unification at Large Scale? Hierarchy Problem! Dark Matter in the Cosmos? Matter/Anti-Matter H New Physics (!) O(TeV) scale phenomenology

42 Unification of Forces

43 R 3(B-L)+2s P = (-) R-Parity Most general superpotential includes terms Violating Baryon number and Lepton number ijk ijk WΔ L= = λ LL i j ek + λ LQ i j d 2 ijk WΔ B= = λ'' ui dj dk 2 New symmetry is postulated k i + μ LH R R i P P u = + = - (particles) (sparticles) u d ~ s - u + e SUSY particles produced in pairs The lightest SUSY particle stable Valid candidate for Dark Matter ( χ 0 ) Distinctive Signature at Colliders Large Missing E T

44 NEW Limits on squark/gluino masses

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46 PRL (2006) Sbottom from Gluino Decays ~ q L ~ q R ~ mixing q ~ q scenario where substantial mixing leads to a sbottom mass eigenstate lighter than gluino 2 ~ g b ~ b M( χ bχ 0 ~ b (00%) 0 (00%) ) > 60 GeV E T > 35 GeV At least three jets E jet T η jet > 5 GeV < 2 At least two b-tags No isolated leptons Cuts on Δφ(E T, jet) E T > 80 GeV 4 events (SM :2.6 ± 0.7) 56 pb- M M ~ g ~ b > 270 GeV > 220

47 Sbottom Pair Production ~ b bχ 0 (00%) E T > 80 GeV At least two jets P jet T η jet > 00 (50) GeV /c <. ( < 2) 0 events At least one b-tag (SM :3.2 ± 0.2) No isolated leptons Cuts on Δφ(E T, jet) M b ~ > 222 GeV /c 95% CL

48 Stop Pair Production scenario with a very light stop CDF Collab., Submitted to PRD ~ t M( χ cχ 0 ) > 0 (00%) 40 GeV Cuts optimized for different stop masses E T > 50 GeV 2 or 3 jets At least one c-tag No isolated leptons Cuts on Δφ, jet) & (E T Δφ(jet, jet) 43 events (SM : 42.7 ± 5.3)

49 Stop Pair Production (II) ~ t Br( χ + ~ b l ν ~ lν) = eμ and μμ channels eμ 34 μμ events (SM :37. ± 2.7 ± 0.9) event (SM : 2.9 ± 0.4 ± 0.) μμ channel presel. cuts

50 Stop Production (RPV in decay) Br( t ~ bτ) = 00% One high-pt lepton (e or μ) One hadronicτ decay At least two jets MT (l,e T ) < 35 GeV lep τ P + P h + E > 0 GeV T E jet T η jet T > 20 GeV < 2.4 T 322 pb- 2 events (SM : ) M ~ t > 55 GeV (@ 95% CL)

51 μ ν φ >ττ b(b) At least central one jet isolated (E jet T muon : p > 5 GeV, η μ T jet > 2 GeV /c < 2.5) one hadronic tau candidate τ τ τ ± ± ± π π h ± ± ± υ υ h τ τ + 0 events (.2 ± 0.2 expected) π h 0 event (2.6 ± 0.3 expected) υ ( π Complementary to other channels τ 0 ) 2 events (2.5 ± 0.2 expected)

52 Higgs would modify the observed relative population of different channels Charged Higgs

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54 Fermiophobic Higgs in 3γ+X In scenario : γ 3 photons (pt > Backgrounds : 30, 25,5 GeV, η γ <.) M h f Br(h < f 90 GeV, M H γγ), Br(H ± < 200 GeV, tanβ ± ± h W ) f > γγγ, Zγ, Wγγ,3jets,2jets + γ and jet + 2γ γγγ backg. estrapolated from γγ data rest estimated using measured fake rates After HT > 25 GeV/c : 0 events (SM backg:.) M M h h f f > 50 95% CL > 80 95% CL (M (M H H ± ± < 50 GeV and tanβ = 30) < 00 GeV and tanβ = 30)

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