Search for Dark Ma-er at CMS

Transcription

1 Search for Dark Ma-er at CMS Thiago Tomei SPRACE UNESP For the CMS Collabora5on

2 Dark Ma-er Simplified Models g c(m c ) g g DM V, A(M med ) V c(m c ) X L vector = g Zµ µ + g Zµ X L axial-vector = g Zµ µ 5 + g Zµ V c µ c µ 5 Be-er descrip;on of DM produc;on at LHC energies. DM + mediator only Dirac fermion DM Spin- or spin mediator Narrow or wide mediator /g radia;on EW boson radia;on Abercrombie et. al., Dark Ma9er Benchmark Models for Early LHC Run- Searches 5/7/6 Thiago Tomei - PPC 6

3 The CMS Detector EM Calorimeter (ECAL) Hadron Calorimeter (HCAL) 3.8 T Magnet Forward Calorimeter (HF) Tracker (Pixel and Strips) Muon System HF Muon Hadronic Calorimeter EM Calorimeter Tracker HF η <.4 η <5. η <3. η <.5 Beam Scin;llator Counters (BSC) 5/7/6 Thiago Tomei - PPC 6 3

4 Event with the highest E t in the 5 monojet analysis! 5/7/6 Thiago Tomei - PPC 6 4

5 CMS: Run Reminder ] χ-nucleon Cross Section [cm CDMSlite χχα (G s 3 4Λ supercdms a ) µν Scalar Spin Independent CMS, 9% CL, 7 TeV, 5. fb CMS, 9% CL, 8 TeV, 9.7 fb (χγ CoGeNT SIMPLE COUPP CDMS II CMS, 9% CL, 8 TeV, 9.7 fb XENON LUX 3 M χ CMS χ)(γ µ Λ Vector µ ) 3 ] χ-nucleon Cross Section [cm CMS, 9% CL, 7 TeV, 5. fb Spin Dependent CMS, 9% CL, 8 TeV, 9.7 fb (χγ γ µ Axial-vector operator 5 SIMPLE COUPP Λ Super-K W W µ χ)(γ γ ) 5 IceCube W W M χ CMS But all these results obtained in the EFT framework! 5/7/6 Thiago Tomei - PPC 6 5

6 Run : Trigger Selec;on DM searches à E T signature. Standard trigger: E, T H T > 9 GeV No muons in the computa;on Control regions Higher L-granularity Op;mized HLT algorithms Efficiency CMS Preliminary ε(e T 5, 3 TeV 4 Trigger: MET9 > 55 GeV) = Offline E T % Events/( GeV) Increased CALO resolu;on: Legacy GCT (lej), Stage (right) 5/7/6 Thiago Tomei - PPC 6 6

7 ergy Scale (JES) Run : Jet E T Reconstruc;on Simulated jet response CMS Simulation 6 JES: Anti-k R=.4, PF+CHS T Barrel Endcap Forward BB EC EC HF 3 TeV p = 3 GeV p = 4 GeV T T.6 p = 6 GeV p = GeV T T p = GeV T Jet η comioning ready. Par;cle Flow algorithm Relative correction CMS Preliminary 6 GeV GeV 4 GeV 48 GeV Nominal Run6.8 fb (3 TeV) Anti-k t R =.4, PF+CHS Charged Hadron Subtrac;on (Coming soon) PileUp Per Par;cle Interac;on (PUPPI) η 5/7/6 Thiago Tomei - PPC 6 7

8 EXO5-3: DM + jets () 6 Events / GeV Events / GeV Data/Pred. g CMS Preliminary. fb (3 TeV) Data Signal (V, TeV) Z(νν) W(lν) Z(ll) Top Dibosons QCD Prefit Ratio Postfit Ratio E T t t t t X X Baseline DM search analysis. Standard trigger One AK4 jet p T > GeV, η <.5 E T > GeV Vetos: E T close to jets B-tagged jets Isolated leptons Surviving SM backgrounds: Z (vv), W (lv) + jets o Lost lepton in the W case Control regions: & ele/mu, single photon g g g 5/7/6 Thiago Tomei - PPC 6 8

9 EXO5-3: DM + jets () Exclusion limit around 5 4 ab, for large range of m DM Run data s;ll more powerful Procedure in place for 6 data analysis More news soon! ) (cm σ SI CMSPreliminary g = g = DM Vector SM Median Expected 9% CL Observed 9% CL. fb (3 TeV) 8TeV - Median Expected 9% CL 8TeV - Observed 9% CL LUX m DM (GeV) 5/7/6 Thiago Tomei - PPC 6 9

10 EXO6-3: DM + (fat) jets () Extension of EXO5-3 with V-tagged jets. Focus: vector and axialvector mediators Boosted jet techniues Z W/Z a.u. CMS.5. Preliminary Simulation Z ν ν 3 TeV Mono-W Vector, m = GeV, m = GeV med DM Mono-W Vector, m = GeV, m = GeV med DM Mono-W Vector, m = 5 GeV, m = GeV med DM a.u.. Z ν ν.5 CMS Preliminary Simulation 3 TeV Mono-W Vector, m = GeV, m = GeV med DM Mono-W Vector, m = GeV, m = GeV med DM Mono-W Vector, m = 5 GeV, m = GeV med DM m pruned (GeV) τ /τ 5/7/6 Thiago Tomei - PPC 6

11 EXO6-3: DM + (fat) jets () High-p T top uarks: source of boosted V bosons. Top uark control region Resonant + non-resonant top contribu;ons Events Per GeV CMS Preliminary.3 fb (3 TeV) Resonant top Non-Resonant top W lν Others Events Per CMS Preliminary Resonant top Non-Resonant top W lν Others.3 fb (3 TeV) 3 Data Data Pruned Mass τ /τ 5/7/6 Thiago Tomei - PPC 6

12 EXO6-3: DM + (fat) jets (3) ] [cm σ SD ] [cm σ SI 34 Axial-vector, Dirac, g =, g = SM Median Expected (8 TeV) 9% CL Median Expected (3 TeV) 9% CL 35 Observed (8 TeV) 9% CL Observed (3 TeV) 9% CL PICO-6 36 PICO-L + - IceCube τ τ + - Super-K τ τ CMS Preliminary CMS Preliminary.3 fb Vector, Dirac, g =, g = SM Median Expected (8 TeV) 9% CL Median Expected (3 TeV) 9% CL Observed (8 TeV) 9% CL Observed (3 TeV) 9% CL LUX SuperCDMS (3 TeV).3 fb (3 TeV) m DM 5/7/6 Thiago Tomei - PPC 6 m DM Vector mediator: comparable to regular monojet Axial-vector: much be-er than direct detec;on (< ab) Events / GeV Data/Pred CMSPreliminary Backgraound (Post-Fit) Backgraound (Pre-Fit).3 fb (3 TeV) Data Z νν W lν WW/WZ/ZZ Top Quark Z/γ ll, γ +jets QCD Higgs Invisible, m = 5 GeV H Vector, M =.5 TeV med Axial-Vector, M =.5 TeV med E T

13 EXO6-7: DM + top () g t FCNC produc;on. Top iden;fica;on. V AK5 jets Sojdrop jet mass + subjets b-tagging in the subjets n-subjerness ra;o Events / GeV - 5/7/6 Thiago Tomei - PPC 6 t 3 / Data / Pred. Data Signal region.3 fb (3 TeV) CMS Preliminary SM backgrounds (pre-fit) SM backgrounds (post-fit) QCD VV Single top W lν tt Z νν FCNC M V =.9 TeV pre-fit post-fit Recoil 3

14 EXO6-7: DM + top () L = L SM + L kin + V µ (g R R µ R + g L L µ L ) Upper limit [σ] [pb] + V µ u i (a FC ) ij µ +(b FC) ij µ 5 u j CMSPreliminary Flavor-changing neutral current.3 fb (3 TeV) Expected Observed σ σ Theory a =b FC =. FC M V Limits in terms of effec;ve Lagrangian. Assump;on: coupling a FC = b FC For coupling =., mediator excluded for masses in range [3, ] GeV. Results in terms of familiar m DM X σ plane. Work in progress 5/7/6 Thiago Tomei - PPC 6 4

15 EXO6-4: DM + photon Events/GeV Data/SM CMS Preliminary.3 fb (3 TeV) γ+jet, W(µν), Z(ll)γ, W(τν), ttγ Beam halo Spikes jet γ MisID electron γ MisID Wγ lνγ Zγ ννγ Bkg. uncertainty ADD, MD=TeV, n=5 Data photon + E T p T > 75 GeV Barrel only ( η <.44) E T > 7 GeV (, E T ) > E T ] (DM-nucleon) [cm σ SI CMS Preliminary s = 3 TeV,.3 fb Vector, Dirac, g =.5, g = DM Observed 9% CL Median expected 9% CL LUX m DM Only 77 events in data. Instrumental backgrounds: W à ev decay Electron mis-id Beam halo ECAL spikes 5/7/6 Thiago Tomei - PPC 6 5

16 Results in m DM x M med m DM CMS Preliminary Vector, Dirac, g =.5, g = DM Observed 95% CL Theoretical uncertainty Median expected 95% CL Expected ±σ s = 3 TeV,.3 fb Observed σ 95% CL /σ TH M med Monojet, mono-v Monophoton m DM CMS Preliminary Axial vector, Dirac, g =.5, g = DM Observed 95% CL Theoretical uncertainty Median expected 95% CL Expected ±σ s = 3 TeV,.3 fb Observed σ 95% CL /σ TH 5 5 5/7/6 Thiago Tomei - PPC M med 6

17 Conclusions The CMS Collabora;on has decided to pour their efforts on the search for Dark Ma-er at LHC. The joint ATLAS-CMS Dark Ma-er Forum produced a series of benchmarks to guide the searches for Run. Focus on spin-, spin mediators. CMS focusing primarily in spin. Axial-vector results more compe;;ve than vector. All E T + X final states being considered. Combina;ons with standard searches (dijets, dileptons, dibosons) in terms of specific models foreseen. Stay tuned for the next results! 5/7/6 Thiago Tomei - PPC 6 7

18 Thank you! 5/7/6 Thiago Tomei - PPC 6 8

19 The author would like to thank the São Paulo Research Founda;on (FAPESP) for the financial support, under Grants No. 3/97-, 3/5479-, and 5/47-4. Acknowledgements 5/7/6 Thiago Tomei - PPC 6 9

20 References The Dark Ma-er Forum Report: Abercrombie et. al., Dark Ma-er Benchmark Models for Early LHC Run- Searches arxiv: CMS Detector Notes Jet energy scale and resolu;on performances with 3 TeV data h-ps://cds.cern.ch/record/6347 MET performance in events with Gamma, Z and dijets using.8 y of 6 Data h-ps://cds.cern.ch/record/6344 CMS Physics Analysis Summaries Search for dark ma-er with jets and ing transverse energy at 3 TeV h-ps://cds.cern.ch/record/487 Search for dark ma-er produc;on in associa;on with jets, or hadronically decaying W or Z boson at srt(s)=3 TeV h-ps://cds.cern.ch/record/483 Search for dark ma-er and large extra dimensions in the gamma+met final state in pp collisions at srt(s) = 3 TeV h-ps://cds.cern.ch/record/69 Search for dark ma-er in associa;on with a boosted top uark in the hadronic final state at srt(s) = 3 TeV h-ps://cds.cern.ch/record/666 CMS Public Results h-p://cms-results.web.cern.ch/cms-results/public-results/publica;ons/ 5/7/6 Thiago Tomei - PPC 6