1 / 38

Pascal Pralavorio (pralavor@cppm2p3.fr)

SUSY searches : lessons from LHC run 1*. Pascal Pralavorio (pralavor@cppm.in2p3.fr). CPPM/IN2P3–Univ. de la Méditerranée (Marseille, FRANCE). Blois 2014 (20 May 2014). Weak Scale SUSY. ``I am sure we all agree that a giraffe is truly beautiful, but she doesn’t seem to serve any purpose”

fauna
Download Presentation

Pascal Pralavorio (pralavor@cppm2p3.fr)

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. SUSY searches : lessons from LHC run 1* Pascal Pralavorio(pralavor@cppm.in2p3.fr) CPPM/IN2P3–Univ. de la Méditerranée (Marseille, FRANCE) Blois 2014 (20 May 2014) Weak Scale SUSY ``I am sure we all agree that a giraffe is truly beautiful, but she doesn’t seem to serve any purpose” J. Weiss (1974) * See 1404.7191 for a full review Pralavorio Pascal SUSY@LHC (Blois 2014)

  2. General Framework (1) • Particle physics is truly beautiful, SUSY serves a natural purpose... • … and predict a mass spectrum of new particles accessible at LHC ! Minimal Supersymetric Standard Model (MSSM) : 29 sparticles + 4 Higgs undiscovered [h0=H(125)] MSSM, aka weak scale SUSY for less than 10% fine-tuning [Dmh2<10xmh2] h10 h20 h1+ h2- S. Martin, SUSY Primer, hep-ph/9709356 L. Hall, BNL SUSY Workshop, Oct 2011 No limit on this spectrum before LHC start !!! ~ ~ ~ ~ h+ h- h10 h20 Pralavorio Pascal SUSY@LHC (Blois 2014)

  3. General Framework (2) • Need three more assumptions before we start • R-Parity (PR=-1 for SUSY particles / +1 for SM particles) is conserved • SUSY particles are pair-produced at LHC and the lightest one is stable • R-parity violation or discrete symmetry also possible (see end of the talk) • The nature of the stable Lightest SUSY particle (LSP) in the MSSM: • case 1: c10with MLSP > GeV or case 2: G with MLSP << GeV • The value of DM=MSUSY[highest particle produced at LHC] - MLSP • Assume generally DM > O(100) GeV  open spectra  high energetic objects • If DM < O(100) GeV  compressed spectra very difficult experimentally ~ ~ These 3 assumptions + naturalness = “plain vanilla” Weak scale SUSY That we can discover (or exclude) at the LHC Pralavorio Pascal SUSY@LHC (Blois 2014)

  4. SUSY at LHC : strategy (1) <1.8MSUSY mEff Courtesy of Anna Sfryla Multijets + ETmiss + 0/1/2 lepton + 0/1/2 photon Inclusive Pralavorio Pascal SUSY@LHC (Blois 2014)

  5. SUSY at LHC : strategy (2) Multi b-jets + ETmiss + 0/1/2 lepton + 0/1/2 photon <MSUSY 3rd generation mCT, Courtesy of Anna Sfryla ElectroWeaK (EWK) 0/1/2 jets + ETmiss + 1/2/3/4 lepton + 0/1/2 photon Pralavorio Pascal SUSY@LHC (Blois 2014)

  6. SUSY at LHC : ingredients Jet energy scale under control ETmiss Tail (and shape) under control ATLAS-CONF-2013-082 CMS DP -2013/010 B-tagging understood Photon understood CMS DP -2013/011 ATLAS-2014-004 Pralavorio Pascal SUSY@LHC (Blois 2014)

  7. SUSY at LHC : keys of the success 1 3 Very low s~1fb - 1pb Powerful discriminants Well understood Monte Carlos s (pb) <1.8MSUSY 1010 Courtesy of Anna Sfryla mEff 105 ATLAS-CONF-2013-047 4 2 Interpretation if no excess 1- Constraint model, e.g. MSUGRA 2- Simplified/topological models 3- Phenomenological models, eg. pMSSM Background estimation 1- Multijets: jet smearing method 2- W, Z, t, VV : control regions 3- ttV: Monte Carlo 1 Pralavorio Pascal SUSY@LHC (Blois 2014)

  8. SUSY at LHC : results ! 2011 2010 2012 e.g. ATLAS (CMS similar) Note: ATLAS Higgs discovery paper: 2500 citations A huge effort from ATLAS and CMS to find SUSY ! Report only on a selection of full 2012 results … Pralavorio Pascal SUSY@LHC (Blois 2014)

  9. EWK SUSY See more in F. Legger’s talk • Closer look at EWK SUSY • Hypotheses for the result presentation • Consider the 3 “extreme” cases • H0, A0, H+/-, q, g, l decoupled (pessimistic) ~ ~ ~ h10, h20,h1+, h2- Governed by M1, M2, m (tanb, mA) Higgs Bosons (See S. Dawson) Bino Wino Higgsino • Production considered at LHC • Highest cross-section O(1)pb : c1+c1-, c20c1+/-(c1+/-c10) • Dominant background : WW, WZ (inc. W) • Unsensitive to c10c10production at LHC when LSP=c10 ~ ~ ~ ~ ~ ~ ~ ~ ~ See more in I. Vivarelli’s talk • Note: these searches also address sleptons (see back-up for more details) ~ ~ ~ ~ h+, h- h10, h20 Pralavorio Pascal SUSY@LHC (Blois 2014)

  10. EWK SUSY (1) ~ • With c10=LSP, consider only scenario (a) • All decaying via on-shell W or Z • At LHC generally consider leptonic decay of W and Z W(*) Z(*) 2l2j/3l + ETmis 2l + ETmiss + 0 jets 1403.5294 • NEW: First limit at LHC ! 2011-2012 gain ! 1403.5294+1402.7029 Pralavorio Pascal SUSY@LHC (Blois 2014)

  11. EWK SUSY (2) ~ • With c10=LSP, consider only scenario (a) • Try also with Higgs in place of Z in c20 decay (e.g if M2≈m) • Combine several Higgs decays (bb, WW, ZZ [gg , tt]) ~ W(*) h0(*) 1-4l + ETmiss CMS-PAS-SUS-13-017 CMS-PAS-SUS-13-017 1l + 2b + ETmiss • NEW: First limit at LHC ! See also ATLAS-CONF-2013-093 Pralavorio Pascal SUSY@LHC (Blois 2014)

  12. EWK SUSY (3) ~ ~ ~ g W g/Z • With G=LSP, driven by c10 decay to G • Scenario (a) gives 2 additional g  ~no background ! • Scenario (b) gives 1 extra W and 1 Z/g  ~no dedicated results yet @ 8 TeV [ATLAS-CONF-2012-144] • Scenario (c) gives 2 extra g/Z/h0 depending on DM and tanb g/Z/h0 (a): gg+ ETmiss (c): h0h0(4b)+ ETmiss (c): ZZ(2l2j,4l)+ ETmiss ATLAS-CONF-2014-001 CMS-PAS-SUS-13-006 CMS-PAS-SUS-13-022 No limit yet ! Pralavorio Pascal SUSY@LHC (Blois 2014)

  13. ~ • 3rd generation squarks : t See more in J. Linacre’s talk Lots of possible decays Very close to ttbartopology (s~240pb) Before LHC no constraints on stop !! Pralavorio Pascal SUSY@LHC (Blois 2014)

  14. ~ • 3rd generation squarks : t (1) • Most powerful analysis: 1l + 4j + ≥1b-jet + ETmiss final state • Design very carefully Signal Region (discriminant var.+ phase space regions) • Can look at two scenarios ~ ~ ~ ~ ~ 100% t ->tc10 100% t ->bc1+ ->bWc1 0 1308.1586 Seriously bites in the naturalness area for open spectra ! Pralavorio Pascal SUSY@LHC (Blois 2014)

  15. ~ • 3rd generation squarks : t (2) • Situation in July 2012 at ICHEP – at the time of the Higgs discovery FIRST LIMITS (July2012) ! √s=7 TeV, L=5fb-1 M(LSP)=200 GeV “If you cover the white space then RPC Weak scale SUSY is probably dead” R. Barbieri (ICHEP2012), Summary Talk Pralavorio Pascal SUSY@LHC (Blois 2014)

  16. ~ • 3rd generation squarks : t (2) • Many other analyses and a lot of progress since ICHEP 2012 FIRST LIMITS (July2012) ! √s=7 TeV, L=5fb-1 “Final” LHC Run I: √s=8 TeV, L=20fb-1 √s=7/8 TeV, L=5/12fb-1 First results @ √s=8 TeV, L=20 fb-1 Different scenarios for c1+ mass  Today not much white space ! Pralavorio Pascal SUSY@LHC (Blois 2014)

  17. ~ • 3rd generation squarks : t (3) • Look at every uncovered corners • Vary the branching ratios 100%->50%, polarization assumptions [ultimately pMSSM] • Very compressed spectra: t1->c c10 • Top mass funel: t2->tc10or t2Z/H t1Z/H t c10 • G=LSP also actively pursued and gives m(t1)>O(500) GeV • NLSP=Higgsino-like : t1 ->bc1+->bff’c10 -> bff’h0(->gg,bb)G • NLSP=Higgsino-like : t1 ->bc1+ -> bff’c10 -> bff’h0(->ZZ)/Z(->ll) G • Other NLSP scenario also looked at, e.g. t1 NLSP: t1bntt1bntnttG ~ ~ CMS-PAS-SUS-13-009, ATLAS-CONF-2013-068 ~ ~ ~ ~ ~ 1405.3886 (CMS), 1403.5222 (ATLAS) ~ ~ ~ ~ ~ ~ • 1312.3310 (CMS) ~ ~ ~ ~ • 1404.5801 (CMS), 1403.5222 (ATLAS) ~ ~ ~ • ATLAS-CONF-2014-014 Pralavorio Pascal SUSY@LHC (Blois 2014)

  18. ~ • 3rd generation squarks : b • 1308.2631 2011-2012 gain ! CMS-PAS-SUSY-13-018 Two possible decay channels: 1- bbc10 Signature: 2 b-jets + Etmiss 2- btc1+/-bWW*c10 Signature: 2 like-sign leptons + Etmiss+ 2 bjets ~ ~ • CMS-PAS-SUS-13-018 ~ ~ ~ Seriously bites in the naturalness area ! Similar for b->tc1+ and G=LSP (covered by G=LSP stop searches) ~ ~ ~ ~ Pralavorio Pascal SUSY@LHC (Blois 2014)

  19. Gluinos searches See more in S. Versille’s talk 1, 2, 3 or 4-step decays ~ G • Note: These searches also address 1st/2nd generation squarks(see back-up for more details) Pralavorio Pascal SUSY@LHC (Blois 2014)

  20. Gluinos searches (1) ~ ~ ~ ~ ~ ~ • With c10=LSP, consider gqq(*)qqc10 / qqWc10 [q=1rst/2nd generation] • With 2-10 high energetic jets+ ETmiss: cover at best compressed / open spectra • To maximize coverage, split in number of leptons (0, 1, 2 generally like-sign) 1 step decay 2 step decay • ATLAS-CONF-2013-062 • ATLAS-CONF-2013-047 • 1402.4770 Pralavorio Pascal SUSY@LHC (Blois 2014)

  21. Gluinossearches (2) ~ ~ ~ ~ ~ ~ • With c10=LSP, consider gqq(*)qqc10/ qqWc10 [q=3rd generation] • With 2-10 high energetic jets + ETmiss • Split in number of leptons (0, 1, 2 like-sign) and bjets(0-3) ~ Open qq dominates ~ ~ ~0.4m(g) ~ ~ Open gttc10 dominates ~ ~m(q) ~ ~ In all cases, m(g)>O(1) TeV for m(c10)>500 GeV! Pralavorio Pascal SUSY@LHC (Blois 2014)

  22. Gluinossearches (3) ~ ~ ~ g • With G=LSP, driven by c10 decay to G • Ask many energetic jets + ETmiss… • … as well as additional photon(s) and eventually leptons/b-jets W g/Z g/Z/h0 (a): gg+ ETmiss (c): gh0(2b)+ ETmiss • 1211.1167 • ATLAS-CONF-2014-001 ~ Here also m(g)>O(1) TeV … Pralavorio Pascal SUSY@LHC (Blois 2014)

  23. Conclusion on natural SUSY • The giraffe turns into dinosaurs ? • Other escape routes provides extra signature at LHC • Vestige of SUSY spectrum at O(TeV) : Generally comes with “long”-lived particles • R-Parity Violation:Multileptons, No Z, multijet resonances, Lepton Flavor Violation • Beyond MSSM: additional scalar particle(s) •  Generally background free searches ! ~ M(Stop)>500 GeV (mLSP<100 GeV) M(g)> O(1) TeV Weak Scale SUSY M(Gauginos) > O(200) GeV Weak scale SUSY still alive if : -- compressed scenario (limits are weaker) -- complicated SUSY spectrum (intricate decay chains) -- hard at low luminosity (c1+c1-WWc10c10), Higgs in cascade ~ ~ ~ ~ Pralavorio Pascal SUSY@LHC (Blois 2014)

  24. Long-Lived Particles See more in I. Tomalin’s talk • ATLAS-CONF-2013-092 • CMS-PAS-EXO-2012-037 • CMS-PAS-EXO-2013-038 Lifetime-Mass limits Gluino Neutralino Chargino • 1310.3675 • (disappearing track) 1404.7191 (non pointing photon) • 1310.6584 (Stopped gluino) See also 1305.0491 (CMS), 1211.1597 (ATLAS), ATLAS-CONF-2013-058 Pralavorio Pascal SUSY@LHC (Blois 2014)

  25. R-Parity Violation See more in R. Franceschini’s talk • R-parity violating search at LHC (48 new Yukawa couplings) • Ex: if one l≠0 and c10 is the LSP spectacular signature forgg Lepton Number Violation (LFV) Baryon Number Violation (BNV) ~ ~ ~ ~ ~ ‘’ l121 ≠0 implies c10emn ≥4 lepton l111≠0 implies c10uuu 2x3 resonant jets • ATLAS-CONF-2013-091 • See also 1311.1799 (CMS) • ATLAS-CONF-2013-036 Pralavorio Pascal SUSY@LHC (Blois 2014)

  26. Beyond MSSM • Dirac gauginosin N=2  scalar gluons (sg) SUSY can be realized in other ways M(sg)<350 GeV sgqq 2x2resonant jets g g sg • 1210.4826 ~ N=2 supermultiplet M(sg)>350 GeV sgtt 2 like-sign leptons • ATLAS-CONF-2013-091 T. Rizzo (SLAC Summer Institute, 01-Aug-12) • Add a new singlet: NMSSM, Stealth SUSY • Relax Higgs mass constraint, remove ETmiss, add more leptons / g / b-jets … (see e.g. 1210.2052) Pralavorio Pascal SUSY@LHC (Blois 2014)

  27. Conclusions • Particle Physics is truly beautiful and SUSY serves a natural purpose • From LHC run1 results, seems not the casefor plain vanilla SUSY (RPC, LSP=c10/G open spect.) • Strongest conclusion: Gluino mass limit above 1 TeV in “all” cases • Stop/SbottomL not present below 500 GeV – still hidding ? • EWKino sector still model dependent. Need more luminosity • Still many ways to escape current limits … • With LHC next run, ATLAS/CMS will continue to explore this uncharted territory ! ~ ~ • ATLAS-PUB-2013-011 • ATLAS-PUB-2013-002 “It ain’t what you don’t know that gets you into trouble. It’s what you know for sure that just ain’t so. ” (M. Twain) Pralavorio Pascal SUSY@LHC (Blois 2014)

  28. SPARE Pralavorio Pascal SUSY@LHC (Blois 2014)

  29. Naturalness (1) • Particle physics is truly beautiful, SUSY serves a natural purpose... • Standard Model (SM) is an effective field theory valid up to LNP M. Veltman, Acta Phys. Polon. B 12, 437 (1981) Dmh2~LNP2 If all t, W, Z, H have s-1/2 partners this could solve the problem Pralavorio Pascal SUSY@LHC (Blois 2014)

  30. Naturalness (2) • Particle physics is truly beautiful, SUSY serves a natural purpose... • Standard Model (SM) is an effective field theory valid up to LNP • SM is natural if Dmh2<mh2[Veltman conditions] LNP<500 GeV [NP will be discovered at LHC!] • Some SUSY realizations are ‘natural’ candidate for New Physics (NP) (e.g. for the top loop) M. Veltman, Acta Phys. Polon. B 12, 437 (1981) S. Dimopoulos, H. Georgi, Nucl. Phys. B193 (1981) 150 Pralavorio Pascal SUSY@LHC (Blois 2014)

  31. All 8 TeV/20 fb-1 ATLAS/CMS results https://twiki.cern.ch/twiki/bin/view/CMSPublic/PhysicsResultsSUS https://twiki.cern.ch/twiki/bin/view/AtlasPublic/SupersymmetryPublicResults 9+23 11+18 https://twiki.cern.ch/twiki/bin/view/CMSPublic/PhysicsResultsEXO Pralavorio Pascal SUSY@LHC (Blois 2014)

  32. SUSY is challenging ! • Majorana particles and elementary scalars are generally hard to find … • but constitute most of the SUSY particle spectrum ! • So not alarming that it takes us some time … MSSM a.k.a Weak Scale SUSY : 29 sparticles + 4 Higgs undiscovered 21! scalars+ 5 Majorana + 3 others fermions Disc. Pred. H 1964 2012 ~ ~ Disc. Pred. q,l 1981 2029??? Still some time ! Disc3 Disc2 Disc1 n* Pred. 1930 1962 2000 1956 Pred. c 2051?? ? 2013? 2007! 1981 * Assuming Majorana Neutrino ~ ~ ~ ~ Excellent framework for an experimentalist  need to push his detector to the best ! h+, h- h10, h20 Pralavorio Pascal SUSY@LHC (Blois 2014)

  33. EWK SUSY: sleptons • Conclusions: • First extensive exploration of SUSY EWK at 8 TeV but no generic mass limits • More final conclusions in 4D (M1, M2, m, tanb) in the making • Still a lot of “natural” phase space to explore … • Note: Unsensitive to c10c10 production at LHC when LSP=c10 • Look also for direct charged sleptons production ~ ~ ~ See more in I. Vivarelli’s talk ~ ~ G=LSP [≥3l+ ETmiss] eR, mR, tR NLSP or co-NLSP c10=LSP [2l+ ETmiss] l= eR, eL, mR, mL ~ ~ ~ ~ ~ ~ ~ ~ 1404.5801 1403.5294 Pralavorio Pascal SUSY@LHC (Blois 2014)

  34. ~ • 3rd generation squarks: b 2 like-sign lepton signature Multi-b signature (hbb) • 1404.2500, 1311.6736 • ATLAS-CONF-2013-061 Pralavorio Pascal SUSY@LHC (Blois 2014)

  35. Gluinossearches • ATLAS-CONF-2013-061 • ATLAS-CONF-2013-061 • ATLAS-CONF-2013-061 • ATLAS-CONF-2013-061 Pralavorio Pascal SUSY@LHC (Blois 2014)

  36. Long-lived Particles • 1305.0491 Pralavorio Pascal SUSY@LHC (Blois 2014)

  37. 1st/2nd generation squarks • ATLAS-CONF-2013-047 • 1402.4770 Pralavorio Pascal SUSY@LHC (Blois 2014)

  38. ATLAS Learning Machine • Use the ATLAS experiment to identify the Higgs boson • Htautau channel • Use simulated data …. • http://www.kaggle.com/c/higgs-boson/ Pralavorio Pascal SUSY@LHC (Blois 2014)

More Related