Dark Matter @ FCC Philip Harris

Dark Matter @ FCC Philip Harris

03/26/15 PH SM@100TeV 1 FermiLAT FCC LZ WMAP Dark Matter @ FCC Philip Harris (CERN)* *Experimentalist 03/26/15 PH SM@100TeV 2 Questions For Consideration ● Whats the place of Dark matter and colliders? ● What are the modes of detection? ● What's it take to find dark matter in a collider? ● What are the limitations on the detector? ● What is a collider's place in the world? ● What other experiments are out there? ● How can we complement? 03/26/15 PH SM@100TeV 3 Dark Matter and Models ● Dark matter models add at least 2 particles In all cases we tag Either : Dark matter as MET signature mediator that couples to Dark matter In some cases we find Or An additional signature additional fermion 03/26/15 PH SM@100TeV 4 Dark Matter and Models ● Dark matter models add at least 2 particles In all cases we tag Either : Dark matter as MET signature Consequently : Searching for additional particles We need to produce the additional particle Motivates going to higher energies 03/26/15 PH SM@100TeV 5 Exception to 2 particle rule ● It is possible for the Higgs to decay invisibly ● We need a lot of Higgs to find invisible decay + - Z ● Can use an e /e collider e+ e- H q Z H q Dijet + Missing Energy above the ZH Resolve the Z di-jet mass ( 10 GeV mass resolution) 03/26/15 PH SM@100TeV 6 Exception to 2 particle rule ● It is possible for the Higgs to decay invisibly ● We need a lot of Higgs to find invisible decay + - ● Can use an e /e collider Arxiv/1402.6287 Andrea De Simone, Gian Francesco Giudice, Alessandro Strumia v Z H v Nothing in your detector Missing Energy resolution against low pT leptons ( <10 GeV) 03/26/15 PH SM@100TeV 7 Exception to 2 particle rule ● It is possible for the Higgs to decay invisibly ● We need a lot of Higgs to find invisible decay + - ● Can use an e /e collider Arxiv/1402.6287 Andrea De Simone, Gian Francesco Giudice, Alessandro Strumia Few models for almost invisible Heavy neutrinos can have a long lifetime Give clealr signature 03/26/15 PH SM@100TeV 8 Exception to 2 particle rule ● It is possible for the Higgs to decay invisibly ● We need a lot of Higgs to find invisible decay + - ● Can use an e /e collider Arxiv/1402.6287 Andrea De Simone, Gian Francesco Giudice, Alessandro Strumia v Z H v Nothing in your detector Missing Energy resolution against low pT leptons ( <10 GeV) 03/26/15 PH SM@100TeV 9 Going to 100 TeV 03/26/15 PH SM@100TeV 10 Building a DM analysis ● Step one : ● Select MET ● Base threshold ● Enough to remove QCD ● What is this threshold? ● Depends on the jet resolution 03/26/15 PH SM@100TeV 11 Shape of 0 MET di-jets ● Consider di-jet events Measured jet pT True jet pT MET = Σ mis-measurements Antonio Boveia, CERN Sergei Chekanov, ANL + Caterina Doglioni, University of Geneva Daniel Dylewsky, University of Georgetown Ana Henriques 03/26/15 PH SM@100TeV 12 Expected QCD Shape ● Compute QCD MET by scanning same jet res ● Using resolution above ● Resulting MET shape is a rayleigh distribution ● Rayleigh : f(MET)=MET/σ2exp(-MET2/σ2) – Sigma is the jet resolution -5 ● Convolve this with jet pT spectrum (dσJ/dpT=pT ) Rayleigh -5 dσJ/dpT=pT (σ=25 GeV) Jet p > 500 GeV X T 03/26/15 PH SM@100TeV 13 MET Resolution ● Resulting shape QCD Jet pT > 500 GeV Sensitive region Normalizing cross sections to approx. expectation from MCFM Comparing with Z : derive a clear bound for MET Planned Summer student on jets+MET with Caterina/Anotino and Ana Henriques 03/26/15 PH SM@100TeV 14 Disappearing Tracks M.Low,L.Wang Arxiv/1404.0682 M.Cirelli,F.Sala,M.Taoso Arxiv/1407.7058 J.Zurita,P.Schwaller,R.Mahbubani Preliminary https://indico.cern.ch/event/352868/session/7/contribution/24/material/slides/0.pdf https://indico.cern.ch/event/352868/session/8/contribution/31/material/slides/0.pdf https://indico.cern.ch/event/352868/session/7/contribution/26/material/slides/0.pdf 03/26/15 PH SM@100TeV 15 Disappearing Track Search ● Two step analysis ● Cut on MET (gets rid of di-jets) ● Look for a disappearing track Compressed spectra Strategy : Select one isolated track No Hits 1404.0682 Hit TALK LINK Hit Hit R.Mahbubani, P. Schwaller, J. Zurita Filippo Sala Low Wang 1404.0682 03/26/15 PH SM@100TeV 16 Decay Length in Design ● What is the decay length needed? ● Expect lifetimes that are on the order of cms Region of interest Low Wang 1404.0682 R.Mahbubani, P. Schwaller, J. Zurita Filippo Sala Low Wang 1404.0682 03/26/15 PH SM@100TeV 17 Disappearing tracker ● Need at least 3 hits to reconstruct a track ● To be robust typically require 5-7 hits Current Min HIts Aggressive min Tracking close to beam drastically enhance signal detection Lifetime (few cm) R.Mahbubani, P. Schwaller, J. Zurita Filippo Sala Low Wang 1404.0682 03/26/15 PH SM@100TeV 18 Disappearing tracker ● Need at least 3 hits to reconstruct a track ● To be robust typically require 5-7 hits Insert number of hits vs η Current Min HIts Aggressive min Tracking close to beam drastically enhance signal detection Lifetime (few cm) Maximize track pT/vertexing parameters R.Mahbubani, P. Schwaller, J. Zurita Filippo Sala Low Wang 1404.0682 03/26/15 PH SM@100TeV 19 Importance of Results Monojet Low & Wang arixv/1404.0682 Monojet Sala,Cirelli,Taoso Arxiv/1407.7058 03/26/15 PH SM@100TeV 20 Arxiv/Soon : P. Harris, V. Khoze, M. Spannowsky, C. Williams Related Study (not show here): Arxiv/1503.02931 : Q. Xiang,X. Bi,P. Yin, Z. Yu Monojet Search 03/26/15 Simplified Models 21 03/26/15 Simplified Models 22 What does this mean? ● Two general classes of models ● Classify by mediator (X) EWK-like (Vector/Axial) Looks & feels like Z+j Vec. mediator couples to SM with EWK ( flavor universal) Higgs-like (Scalar/Pseudoscalar) Looks & feels like gluon fusion Scalar mediator couples to SM with yukawa ( α mass) 03/26/15 Simplified Models 23 Collider vs the rest of the world ● Simplified models allow us to compare Indirect Detection Dark matter annihalates produces photons... eventually Colliders Produce mediator produce dark matter Direct Detection Χ X Dark matter scatters Leaves recoiling nucleus q q 03/26/15 PH SM@100TeV 24 Monojet and Simplified Models Vector (spin-independent) Axial (spin-dependent) EWK style coupling EWK style coupling (flavor universal) (flavor universal) Scalar Pseudoscalar Yukawa style coupling Yukawa style coupling (Mass based coupling) (Mass based coupling) 03/26/15 PH SM@100TeV 25 Strategy ● Compare increase in exclusion range w/14 TeV ● As a benchmark : ● Use CMS monojet analysis @14TeV as benchmark ● Run this for 1 ab-1 – Take scalar+j or scalar+jj dark matter as base ● MCFM for 1 jet and VBF@NLO for 2jet (finite mass in the loop) ● Benchmark analysis can futher be optimized – No rescanning done ● Future detector : ● Use CMS resolution ● Full analysis @100 TeV ● Re-scan all the cuts and run the analysis 03/26/15 PH SM@100TeV 26 Monojet vs Disappearing tracks Procedure: Monojet Analysis MET > X Remove Select Suffer Remove QCD Leptons Jet In monojet we can only tag ISR jet Find disappearing tracks Remove all background Disappearing track 03/26/15 PH SM@100TeV 27 Next Step : remove leptons ● Standard model backgrounds with real MET ● W→lv : Identify events with a lepton if we see it ● Z→vv : No way to tag this without MET Loose id effective lepton veto MET > 200 GeV Can reduce W by 70% With ATLAS or CMS we can identify : Muons with pT > 10 GeV 96% Efficiency Arxiv/Soon Electrons with p > 15 GeV 92% Efficiency T PH,V. Khoze,C. Taus with pT > 15 GeV 85% Efficiency Williams,M.Spannowsky 03/26/15 PH SM@100TeV 28 What is the lepton range? pT > 20 GeV MET > 200 GeV ● Leptons range out to an η value of |η| < 5.0 ● Designing a detector to identify η out to this range ● Samples/Info : ● NNPDF 3.0 for everything (LO for LO and NLO for..) ● aMC@NLO NLO 0,1,2 jet for Z+jets (FxFx) ● aMC@NLO NLO 0,1 jet for W+jets (FxFx) 03/26/15 PH SM@100TeV 29 After Lepton removal ● Next step is to select a jet MET > 200 GeV Scale & PDF Uncertainties Arxiv/Soon Jets go as far as |η| < 7.0 in PH,V. Khoze,C. Williams,M.Spannowsky 03/26/15 PH SM@100TeV 30 Effect of Jet/MET smearing ● Pre detector effects 03/26/15 PH SM@100TeV 31 Effect of Jet/MET smearing ● Post detector effects MET resolutions of the scale of LHC Influence of signal discrimination is minimal 03/26/15 PH SM@100TeV 32 Selecting on Jets ● Monojet is not a monojet any more ● Cannot trust 1jet MC (2/3 or … important at 100 TeV) p of 2nd jet is low when No discrimination in number of jets T (also look at the number) parton shower used 03/26/15 PH SM@100TeV 33 The Analysis Perform full shape analysis with binning list below Correlated Uncertainties Per bin Di-boson Lep. Eff. uncertainty CorrelatedUnc. from Z→μμ Per bin Di-boson/Lep. effi uncertainty from W→μv Additional 1%/bin uncertainty High luminosity Z and W background dominated by : 1% systematic uncertainty 03/26/15 ● Inclusive cross sectionlimits Inclusive cross (pT jet > 15 GeV) PRELIMINARY EXTREMELY PH SM@100TeV PH Results Note Vector/Axial/Pseudoscalar similarVector/Axial/Pseudoscalar Note Benchmarks @100 TeV @100 HH cross section HH section ttH cross ggH crosssection 34 03/26/15 PH SM@100TeV 35 Results ● Inclusive cross section limits EXTREMELY PRELIMINARY Substantial gains at high mediator mass Reminder (14 TeV needs re-tune) Note Vector/Axial/Pseudoscalar similar 03/26/15 PH SM@100TeV 36 Comparing with Direct Detection ● Considering first vector and axial mediators EXTREMELY PRELIMINARY EXTREMELY PRELIMINARY ● For vector mediator direct detection still ● Large improvement is present ● At high dark matter mass is particularly large 03/26/15 PH SM@100TeV 37 Comparing with Direct Detection

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