Search for diboson resonances at CMS

Search for diboson resonances at CMS identifying highly energetic boson decays and discriminating new physics signals from the standard model background Clemens Lange (CERN) DESY Physics Seminar Hamburg/Zeuthen 3 st May/ st June 206

About diboson resonances [https://ideas.lego.com/projects/94885] heavy resonances? boson jets? background estimation? ( wasn t ) there this diphoton resonance? 3.05.206 Clemens Lange - Diboson resonances searches at CMS 2

We have a problem >how can we explain the big difference between the weak force and gravity? µ 2 = v 2 = g 2 4M 2 W 4 GeV 2 M Pl 38 GeV 2 >no symmetry in the standard model (SM) protects the Higgs mass >µ H 2 always a singlet under phase transformations > natural explanation would be that SM is replaced by another theory at the TeV scale: µ 2 ~ (heavier scale) 2 new particles H t t H >these theories could be: >SUSY: protecting the Higgs mass by a symmetry >Composite Higgs: the Higgs is not elementary > Large/warped extra dimensions: gravity is strong at electroweak scale 3.05.206 Clemens Lange - Diboson resonances searches at CMS 3

Composite Higgs? [https://www.learner.org/] t >the Higgs could be nonfundamental >instead: bound state of a new strong interaction >e.g. size of 8 m ~ Fermi scale (0 GeV)! light Higgs like a pion from a new sector >solves hierarchy problem, and brings along new heavy particles/states >heavy partners of SM particles decay to lighter ones (W, Z, H, top, ) H t H 3.05.206 Clemens Lange - Diboson resonances searches at CMS 4

Large extra dimensions? Eric Williams >another attempt to solve the hierarchy problem >SM fields are confined to fourdimensional membrane, gravity propagates in additional dimensions >effectively, change power law of gravity from /r 2 to /r 2+N, where N = number of extra dimensions >this only applies to particles with r N - smaller things have more possibilities to move > large, because of size mm to ~/TeV >proposed by Arkani-Hamed, Dimopoulos, and Dvali (ADD) gravity Planck-brane bulk gravity can propagate through bulk TeV-brane 3.05.206 Clemens Lange - Diboson resonances searches at CMS 5

Warped extra dimensions? Eric Williams >often referred to as Randall- Sundrum (RS) models >warping causes energy scale at one end of the extra dimension to be much larger than at the other end >SM models reside on TeV-brane (in RS models) >bulk graviton models allow SM particles into 5D-bulk >overlap of 5-D profiles at TeV-brane (and Higgs) determine particle masses >additionally, if distance between two branes is not fixed, additional fluctuations can occur gravity Planck-brane RS model bulk gravity can propagate through bulk bulk Bulk model TeV-brane 3.05.206 Clemens Lange - Diboson resonances searches at CMS 6

How do we observe these models at the LHC? >should be able to observe excitations/ resonances/fluctuations q b >composite Higgs: electroweak composite vector resonances H b! mostly spin (W, Z )! decay to pairs of W, Z, H W 0 W >Randall-Sundrum: Kaluza-Klein excitations of gravitons + radion fluctuations >gravitons (spin-2):! RS: decay predominantly to leptons q 0 g l q! bulk: decay to pairs of W, Z! ADD: broader excess from many narrow-spaced resonances W q >radions (spin-0):! only used for signal modelling here X W >focus here on narrow resonances (width < detector resolution), mass 600 GeV g l 3.05.206 Clemens Lange - Diboson resonances searches at CMS 7

What about the diphoton resonance? >neutral resonance could be graviton or radion as in diboson searches >resonance cannot directly couple to photons loop of charged particles (e.g. W, top,?) in decay (and production?) >there must be more than just a di-photon resonance >searches presented in this talk constrain what physics models this potential resonance could be 3.05.206 Clemens Lange - Diboson resonances searches at CMS 8

Reconstructing heavy resonances >bosons will be very energetic collimated decay products >need to develop dedicated reconstruction methods >hadronic decays of bosons:! boson-tagging! exploiting substructure of jets >leptonic decays:! special isolation for dileptonic decays! dedicated reconstruction algorithms for high-pt leptons! new tau-identification algorithms focus here on Run-2 developments and analyses 3.05.206 Clemens Lange - Diboson resonances searches at CMS 9

Hadronic boson identification JHEP 2 (204) 07 >at CMS use anti-kt jet algorithm with R = 0.4 >already for resonances of TeV a significant fraction of cases where the boson decay is contained in a single jet >increase jet size to R = 0.8 to contain full decay within fat jet R = p 2 + 2 Reconstruction efficiency 0.8 0.6 0.4 0.2 Merged jet efficiency single CA R=0.8 jet R (W,jet) < 0. Resolved jets efficiency two AK R=0.5 jets R (q,jet ) < 0. i j 0 200 400 600 800 00 200 W boson p T 8 TeV CMS Simulation (GeV) R qq 2 M V p V T back of the envelope calculation: for a resonance of mass TeV the bosons from the decay will have p T ~0.4 TeV ΔR 0.4 3.05.206 Clemens Lange - Diboson resonances searches at CMS

CMS particle flow reconstruction >tracking detectors and calorimeters contained in magnetic field >particle flow algorithm makes use of sub-detectors with best resolution (both spatial and energy) >actual particles enter jet clustering 3.05.206 Clemens Lange - Diboson resonances searches at CMS

Jet pruning CMS-PAS-HIG4-008 >we know the masses of W, Z and Higgs very well can use them as constraints >however, large number of particles in jet rather bad resolution >jet pruning (generally grooming) removes soft and large angle radiation arbitrary units 0.2 CMS Simulation SM Higgs, m = 600 GeV ungroomed jet mass W+Jets, MadGraph+Pythia6 ungroomed jet mass >strategy: 0.! recluster jet using Cambridge-Aachen (CA) jet algorithm? pruned jet mass 0 0 50 0 50 3.05.206 Clemens Lange - Diboson resonances searches at CMS 2

Reminder: jet clustering algorithms JHEP 0804:063,2008 >kt-algorithms: sequential clustering >examine four-vector inputs pairwise and construct jets hierarchically >anti-kt: preferentially merge constituents with high pt with respect to their nearest neighbours first >Cambridge-Aachen: no ptweighting, merge based on spatial separation only undoing clustering yields subjets 3.05.206 Clemens Lange - Diboson resonances searches at CMS 3

Jet pruning CMS-PAS-EXO5-002 >we know the masses of W, Z and Higgs very well can use them as constraints >however, large number of particles in jet rather bad resolution >jet pruning (generally grooming) removes soft and large angle radiation >strategy: Events / 5.00 GeV 500 400 300 200 3 CMS Preliminary CMS Data W (G (2 TeV) WW (MADGRAPH)) Bulk Z (G (2 TeV) ZZ(MADGRAPH)) Bulk W (W' (2 TeV) QCD PYTHIA8 2.6 fb WZ (MADGRAPH)) (3 TeV)! recluster jet using Cambridge-Aachen (CA) jet algorithm! soft : min(p i T,p j T )/ p T < R ij >m orig /p orig! large angle : T, orig = unpruned CA jet >cut on mass window (~± GeV) Data MC 0 0 0 50 0 50 200 250 300.5 0.5 0 50 0 50 200 250 300 Pruned mass [GeV] 3.05.206 Clemens Lange - Diboson resonances searches at CMS 4

N-subjettiness JHEP 3:05,20 >for boson-tagging: want to quantify how 2-subjetty a jet is Boosted W Jet, R = 0.6 > to what extent is energy flow aligned along 2 momentum directions (N=2)? N = d 0 X normalisation k 2 p T,k min( R,k,.8 R 2,k,..., R N,k ) sum over particles 0.2 0 0.2 0.4 0.6 0.8 η low values of τn compatibility with the hypothesis of N axes 2.2 (a) Boosted W Jet, R = 0.6 φ 2.2.6.4.2 5.8 minimise distance to candidate subjets (b) Boosted QCD Jet, R = 0.6 2 axes axis W-jet 2.8 5.6 5.4 QCD-jet φ.6.4 φ 5.2 5.2 4.8 4.6 0.2 0 0.2 0.4 0.6 0.8 η.2 0.8 0.6 0.4 0.2 η 3.05.206 (c) (b) (d) Clemens Lange - Diboson resonances searches at CMS 5

N-subjettiness ratio CMS-PAS-EXO5-002 >bare τn has very little discrimination power >take ratio τ2/τ instead >mind: rather complicated variable, difficult to model need to validate in data >clean sample of W-jets: top-antitop quark pairs used for calibration Events / ( 0.04 ) 350 CMS CMS Data tt 300 250 200 50 0 50 Preliminary Single Top W+jets WprimeTeV x 50 2.2 fb VV (3 TeV) MC Stat Events / 0.05 4000 2000 000 8000 6000 4000 2000 CMS Preliminary CMS Data G Bulk G Bulk (2 TeV) (2 TeV) W' (2 TeV) QCD PYTHIA8 65 GeV < M P < 5 GeV 2.6 fb (3 TeV) WW (MADGRAPH) ZZ(MADGRAPH) WZ (MADGRAPH) Data / MC 0 2.5 0.5 0 0.2 0.4 0.6 0.8 τ 2 /τ Data MC.5 0.5 0 0. 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 0 0. 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 τ 2 3.05.206 Clemens Lange - Diboson resonances searches at CMS 6

Higgs bb tagging EXO4-009 CMS DP-205/038 >Higgs has higher mass than W/Z bosons τ2/τ less important, exploit b-jet content instead >two different strategies: Arbitrary scale 0.4 0.3 0.2 CMS Simulation q/g MADGRAPH+PYTHIA t Wb qq'b H bb H WW* 4q W qq' Z qq CA pruned R=0.8 8 TeV! identify b-subjets! tag fat jet >currently, both show comparable performance >50% lower mis-tagging rate than W-/Z-tagging >dedicated Higgs-tagger available soon 0. 0 0 50 0 50 200 Jet mass m j (GeV) H WW qqqq tagging is done using τ4/τ2 ratio (cf. τ2/τ for W/Z) 3.05.206 Clemens Lange - Diboson resonances searches at CMS 7

Higgs ττ tagging CMS-PAS-EXO5-008 >τ-lepton can decay hadronically and leptonically τ H >need to take into account potential overlap between the two τ-leptons π ν τ! remove tracks/particles entering other isolation cone μ h ν >discrimination against q-/g-jets: MVA-based isolation! sum reconstructed particle energies in various cones around τ decay products >neutrinos in decay cannot be reconstructed missing energy! ττ-reconstruction using templates from Monte Carlo simulation (SVfit) currently only 8 TeV results Events / GeV b-tagged ν untagged CMS Preliminary 9.7 fb (8 TeV) 35 Drell-Yan + jets tt 30 25 20 5 5 W + jets Single top Diboson QCD multijets Signal 30 (M =.5 TeV, X Observed Λ R =) 20 40 60 80 0 20 40 60 80 200 220 240 M(τ,τ) [GeV] 3.05.206 Clemens Lange - Diboson resonances searches at CMS 8

Lepton (muon + electron) reconstruction CMS DP-203/003 >two isolation issues:! radiation from highly energetic leptons spoils isolation! leptons spoil each other s isolation >employ dedicated high-pt algorithms to preserve high efficiency >loosen selection criteria one of the leptons in Z ll decays >leptonic W-decay: need to recover z-component of neutrino! use W-mass constraint for reconstruction Efficiency Scale Factor 0.95 0.9 0.85 0.8 0.75..08.06.04.02 0.98 0.96 0.94 0.92 0.9 High energy electron ID (HEEP) CMS Preliminary, Barrel, E >35 GeV T s = 8 TeV, L dt = 9.6 fb DATA (BG subtracted) DY (MC) 40 50 60 70 0 200 300 400 500 00 E T (GeV) 3.05.206 Clemens Lange - Diboson resonances searches at CMS 9

Strategy/event selection for VV analyses trigger VV qqqq analysis VW qqlν analysis VZ qqll analysis HT trigger (800 GeV) or jet+groomed mass single lepton trigger (e/µ p T > 5/45 GeV) lepton(s) HEEP e/high-pt µ special iso/id for 2 nd lepton V-jet V boson candidate(s) X anti-kt R=0.8, pt > 200 GeV, exploit substructure τ2/τ, use groomed mass Δη <.3 reconstruct leptonic V, pt > 200 GeV use mass window additional cuts on separation of bosons in Δɸ and ΔR reconstruct X using both reconstructed vector bosons search for bump in mvv distribution X W ` W q q 3.05.206 Clemens Lange - Diboson resonances searches at CMS 20

Dijet (VV) analysis CMS-PAS-EXO5-002 >trigger at ~0% efficiency at mjj > TeV! apply cut on reconstructed dijet system >define different τ2/τ regions:! high purity to suppress background! low purity to recover signal efficiency at high masses >split W and Z samples based on pruned jet mass (65-85, 85-5 GeV) >still dominated by QCD multi-jet events >difficult to obtain sufficient MC simulation statistics >need a data-driven approach >exponentially falling spectrum: use fit function Events / 0.05 Data MC 4000 2000 000 8000 6000 4000 2000.5 0.5 CMS Preliminary CMS Data G Bulk G Bulk (2 TeV) WW (MADGRAPH) (2 TeV) ZZ(MADGRAPH) W' (2 TeV) WZ (MADGRAPH) QCD PYTHIA8 65 GeV < M P < 5 GeV HP LP 2.6 fb (3 TeV) 0 0. 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 0 0. 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 τ 2 3.05.206 Clemens Lange - Diboson resonances searches at CMS 2

VV background estimation CMS-PAS-EXO5-002 >naively, fitting the m JJ spectrum could swallow signal >also, need to avoid claiming false discovery (in particular in tail) >fit function: Events / 94.7 GeV 4 3 2 CMS Preliminary CMS data 2 par. background fit G(2 TeV) WW (σ = 0.04 pb) WW, low-purity η < 2.4, p T M jj > TeV, η 2.6 fb (3 TeV) > 200 GeV <.3 jj or 2 parameters 3 parameters >number of free parameters determined by F-test:! check if quality of fit improves by > % confidence level! if not, stick with current fit function >extensive bias tests conducted >combined signal+background fit performed 3 2 0-2 -3 Data-Fit σ 00 500 2000 2500 3000 3500 Dijet invariant mass [GeV] very similar background estimation strategy as for diphoton resonance search 3.05.206 Clemens Lange - Diboson resonances searches at CMS 22

Intermezzo: Zɣ search overview CMS-PAS-EXO6-09 >recently published Z ll + ɣ search >inspired by ɣɣ excess >same photon ID as ɣɣ search, dilepton ID as in ZV search, fit background > limited by statistics, no significant excess Events / ( 20 GeV ) 2 CMS Preliminary muon channel 2.7 fb (3 TeV) Data Fit Uncertainty Events / ( 20 GeV ) CMS Preliminary electron channel 2.7 fb (3 TeV) Data Fit Uncertainty (data-fit)/σ stat 3.05.206 2 0 2 200 400 600 800 00 200 400 - M(µ + µ γ) [GeV] (data-fit)/σ stat 2 0 2 200 400 600 800 00 200 400 Clemens Lange - Diboson resonances searches at CMS + - M(e e γ) [GeV] 23

VW/VZ analysis overview CMS-PAS-B2G6-004 >for 205 data, two separate analyses performed:! low mass : 600-00 GeV! high mass : -4 TeV! VZ analysis not yet public >difference low vs. high mass:! lower boost can use isolated lepton triggers with 27 GeV thresholds >requiring an isolated lepton suppresses QCD multi-jet background significantly >dominant backgrounds: Events / ( 20 ) Data / MC.8.6.4.2 0.8 0.6 0.4 0.2 0 2.5 0.5 3 CMS Preliminary CMS Data VV Single Top WprimeTeV x 50 2.2 fb W+jets tt (3 TeV) MC Stat 0 200 300 400 500 600 700 AK8 pt (GeV)! Drell-Yan/W+Jets! top-antitop quark production >can estimate individual background components from sidebands 3.05.206 Clemens Lange - Diboson resonances searches at CMS 24

VW analysis background estimation CMS-PAS-B2G6-004 CMS-PAS-EXO5-002 >statistics in MC simulated samples still limited >furthermore, analysis performed in extreme phase space >use pruned mass sidebands (40-65 GeV, 3560 GeV) to exploit correlation between pruned jet mass and resonance mass! Higgs mass region kept blind >determine ratio of simulated to data distributions in sideband >extrapolate to signal region using transfer function (based on simulation) >method accounts for data-mc differences in shape and normalisation 40 60 80 0 20 40 Pruned jet mass (GeV) 3.05.206 Clemens Lange - Diboson resonances searches at CMS Events / ( 5 GeV ) σ data Data-Fit Events / ( 0 GeV ) 350 300 250 200 50 0 50 2 0-2 σ data Data-Fit 4 2 CMS Preliminary -2 2 0-2 CMS signal region WW enriched CMS Data µν WW/WZ Single Top WZ enriched CMS Data eν 3 Preliminary WW/WZ Single Top G Bulk M G =2 TeV ( 0) W+jets tt 2.2 fb (3 TeV) Uncertainty High-Purity Higgs 2.2 fb (3 TeV) W+jets 3.5 2 2.5 3 3.5 4 (GeV) tt Uncertainty High-Purity, WW enriched M WV 25

Intermezzo: ɣɣ vs. Zɣ vs. WW >limits for narrow resonances! caveat: slightly different models used > minimal upward fluctuations? BR(A Zγ) [fb] 95% CL UL on σ CMS Preliminary 300 250 200 50 0 50 Zɣ W = 0.04% 2.7 fb (3 TeV) Observed Expected ± σ Expected ± 2σ CMS-PAS-EXO5-004 CMS-PAS-EXO6-09 CMS-PAS-B2G6-004 0 400 600 800 00 200 400 600 800 2000 Resonance Mass [GeV] WW)(pb) Bulk 2 CMS Preliminary WW 2.3 fb (3 TeV) Asympt. CL Expected S Asympt. CL Expected ± s.d. S Asympt. CL Expected ± 2 s.d. S σ BR, k = 0.5 TH GBulk WW Asympt. CL Observed S ɣɣ σ 95% x BR(G -2 W lν -3 600 700 800 900 00 (GeV) M G 3.05.206 Clemens Lange - Diboson resonances searches at CMS 26

VH analysis overview CMS-PAS-B2G6-003 >205 data: H bb, leptonic W/Z decays! W lν! Z ll! Z νν >categorise in single and double subjet b-tag categories > same background estimation method as for VW search Events / 5.0 GeV 45 40 35 30 25 20 X Vh (ll,lν,νν)bb CMS Preliminary 0l, b-tag LSB VV Higgs HSB 2.7 fb Data V+jets Top, ST VV, VH Bkg. unc. (3 TeV) Events / 0.0 GeV Z νν, b-tag 2 X Vh (ll,lν,νν)bb CMS Preliminary 0l, b-tag 2.7 fb (3 TeV) Data V+jets Top, ST VV, VH Bkg. unc. m X =2000 GeV HVT model B 5 Pulls 5 0 4 02 4 2 3.05.206 50 0 50 200 250 300 jet pruned mass (GeV) Pulls 2 00 500 2000 2500 3000 Clemens Lange - Diboson resonances searches at CMS 4 02 4 2 mvh T (GeV) 00 500 2000 2500 3000 (GeV) mvh T 27

Signal modelling and uncertainties CMS-PAS-B2G6-003 >depending on spin of new particles, polarisation of bosons different >Bulk graviton (spin-2) and W /Z (spin) models primarily couple to longitudinal components of W/Z >analytical description of signal shapes based on fully simulated benchmark mass points! double-sided Crystal-Ball function! linearly interpolation between benchmark points >signal efficiency up to 5% depending on analysis category >largest uncertainties: Arbitrary units 0.6 0.5 0.4 0.3 0.2 0. X Vh (ll,lν,νν)bb 0.7 CMS Simulation Preliminary 2µ channel Z µµ, b-tag 0 0 500 00 500 2000 2500 3000 3500 4000 4500 5000 (GeV) m Vh 3 TeV m X =800 GeV m X =00 GeV m X =200 GeV m X =400 GeV m X =600 GeV m X =800 GeV m X =2000 GeV m X =2500 GeV m X =3000 GeV m X =3500 GeV m X =4000 GeV! background estimation! jet energy and mass scale! boson-tagging 3.05.206 Clemens Lange - Diboson resonances searches at CMS 28

Model interpretation arxiv:404.02 GH GeVL >several different analyses performed >advantageous to use common 0.benchmark models for easier interpretation 0.0 gg >need to know individual couplings tt to bosons 0.00 Bulk ZZ WW hh aa GH GeVL 0. 0.0 0.00 RS ZZ WW hh aa gg tt qq ll nn - 4 rams! individual analysis: e.g. σ(gg G WW) 200 400 600 800 00 200 400 ure V.4: MGr H GeVL! combination: e.g. σ(gg G)! mind also production mechanism Bulk KK-graviton branching fractions. Left: Bulk scenario, assuming elementary t ZZ rk. Right RS scenario. The dashed line represents the individual RS kk-graviton dec b 0. WW s to a pair of light fermions f f, where f represents both light quarks (u, d, s, c, b) or lepto, ). Branching ratios are independent of k parameter. b g X W W q q 200 400 600 800 00 200 400 arios l for third g family WED embedding: l The thick curves considers MGr H GeVL a fully elementa (b) s3.05.206 not a surprise to note that kk-graviton Clemens Lange - branching Diboson resonances ratios searches toat CMS bosons pais (W/Z/H 29 GH GeVL - 4 200 400 600 800 00 200 400 0.0 0.00-4 MGr H GeVL Figure (V.5) shows a zoom of kk-graviton branching ratios comparing two distin quark [60] while thin dashed ones we ignores kk-graviton coupling with top quar hh aa gg tt

Model tuning >models described before can be tuned by a handful of parameters >bulk graviton:! mass of graviton! coupling constant determining production cross section and width >heavy vector triplet (HVT): BRHV 0 Æ 2 XL -2-3 Model B.07/JHEP09(204)060 heavy vector triplet (HVT) W + W - Zh uu dd g V = 3 ll è nn bb tt è Feynman diagrams GHV 0 Æ 2 XL @GeVD! phenomenological Lagrangian! describes production and decay of heavy spin resonances Model A! 4 parameters for resonance g V = mass, interaction strength, couplings g V = 2 to bosons g and fermions V = 3! focus here on Model B with enhanced couplings to bosons 500 00 500 2000 2500 3000 3500 4000 M 0 @GeVD 3.05.206 Clemens Lange - Diboson 500 resonances 00 500 searches 2000 at CMS 2500 3000 3500 4000 GHV 0 Æ 2 XL @GeVD 3 2 q Model B q 0 W 0 H W g V = 3 g V = 5 g V = 8 b l b 30

Putting it all together >currently, larger number of channels has been covered with 8 TeV data >differentiate between final states (number of leptons and jets) >violet analyses interpreted in dark matter scenarios W lν Z ll V qq Z νν H qqqq H ττ H bb H ɣɣ W lν 3 TeV 3 TeV Z ll 3 TeV 3 TeV V qq 3 TeV 3 TeV 3 TeV 3 TeV Z νν 3 TeV 3 TeV H qqqq H ττ H bb 3 TeV 3 TeV 3 TeV H ɣɣ >several analyses repeated and improved w.r.t. 8 TeV (considering mx > TeV) >several more to come this year 3.05.206 Clemens Lange - Diboson resonances searches at CMS 3

8 vs. 3 TeV >While 3 TeV has opened up new energy regime, integrated luminosity recorded in 205 significantly below the one of 202 0 ratios of LHC parton luminosities: 3 TeV / 8 TeV WJS203! 20 fb vs. ~3 fb >LHC is hadron collider - s energy available in collision >need to consider parton luminosities luminosity ratio gg_ Σqq qg >exceed 202 reach with 205 data already at -2 TeV resonance mass 0 00 M X (GeV) MSTW2008NLO [website] >nevertheless, worthwhile combining results 3.05.206 Clemens Lange - Diboson resonances searches at CMS 32

Combination of diboson analyses CMS-PAS-B2G6-007 >example here: V combination in HVT model B >seven 8 TeV analyses, three at 3 TeV >how to combine upper cross section limits from two different s? (pb) CMS Preliminary 9.7 fb (8 TeV) (pb) CMS Preliminary 2.2-2.6 fb (3 TeV) BR V' WV/VH Asympt. CL S Asympt. CL Asympt. CL HVT B S S (g =3) V Obs. Exp. ± σ Exp. ± 2σ BR V' WV/VH Asympt. CL S Asympt. CL Asympt. CL HVT B S S (g =3) V Obs. Exp. ± σ Exp. ± 2σ σ 95% σ 95% -2 lllv llqq lvqq lvbb qqqq qqbb(4q) qqττ -2 lvqq llbb/lvbb/vvbb qqqq.5 2 2.5 M V' (TeV) 2 3 4 M V' (TeV) 3.05.206 Clemens Lange - Diboson resonances searches at CMS 33

Combination of diboson analyses CMS-PAS-B2G6-007 >convert cross section limits into signal strength limits >8+3 TeV limits comparable at lower masses, 3 TeV dominates high mass > lower masses: leptonic analyses, higher masses: hadronic final states σ 95% /σ theory 2 CMS Preliminary 2.2-2.6 fb (3 TeV) + 9.7 fb lllv (8 TeV) qqbb(4q) (8 TeV) llqq (8 TeV) qqττ (8 TeV) lvqq (8 TeV) lvqq (3 TeV) lvbb (8 TeV) llbb/lvbb/vvbb (3 TeV) qqqq (8 TeV) qqqq (3 TeV) (8 TeV) σ 95% /σ theory 2 CMS Preliminary 2.2-2.6 fb (3 TeV) + 9.7 fb Asympt. CL S (8 TeV) Obs.(solid)/ Exp.(dashed) HVT B (g =3) V Asympt. CL S Asympt. CL Asympt. CL HVT B S S (g =3) V Obs. Exp. ± Exp. ± σ 2σ 8 TeV 3 TeV 8+3 TeV 2 3 4 M V' (TeV) 2 3 4 M V' (TeV) 3.05.206 Clemens Lange - Diboson resonances searches at CMS 34

Combination of diboson analyses CMS-PAS-B2G6-007 >can translate observed limits into exclusion contours in the HVT couplings space >additional input to theorists for model building V g 2 cf /g coupling to fermions 0.5 0-0.5 CMS Preliminary B 2.2-2.6 fb (3 TeV) + 9.7 fb (8 TeV).5 TeV 2 TeV 3 TeV Γ th M > 7% σ exp M -3-2 0 2 3 coupling to bosons g c V H 3.05.206 Clemens Lange - Diboson resonances searches at CMS 35

Summary >discovery of a diboson resonance might solve hierarchy problem >however, currently no sign of new physics >3 TeV results already exceed 8 TeV ones > expect another boost with 206 data 3.05.206 Clemens Lange - Diboson resonances searches at CMS 36

W-tagging calibration >cutting on τ2/τ-ratio need to know efficiency of cut in data and simulation >select at generator level clean W-events and those that do not match > perform simultaneous fit Events / ( 5 GeV ) 350 300 250 2.2 fb CMS at Preliminary s = 3TeV tt VV single Top W+jets data W e/µ ν HP Events / ( 5 GeV ) 240 220 200 80 60 40 2.2 fb CMS at Preliminary s = 3TeV tt VV single Top W+jets data W e/µ ν HP 200 20 50 0 80 0 60 50 40 20 40 50 60 70 80 90 0 20 30 pruned jet mass (GeV) 40 50 60 70 80 90 0 20 30 pruned jet mass (GeV) 3.05.206 Clemens Lange - Diboson resonances searches at CMS 38

boson-tagging efficiencies Tagger BR(W/Z/H xx) efficiency W/Z qq 70 % 35 %.2 % H bb 57 % 35 % 0.5 % H WW qqqq % 35 %.5 % mistag rate (q-/g-jets) H ττ 6 % 35 % 0.03 % 3.05.206 Clemens Lange - Diboson resonances searches at CMS 39

Zɣ search limits CMS-PAS-EXO6-09 >recently published Z ll + ɣ search 0.04% width 5.4% width BR(A Zγ) [fb] CMS Preliminary 300 250 200 W = 0.04% 2.7 fb (3 TeV) Observed Expected ± σ Expected ± 2σ BR(A Zγ) [fb] CMS Preliminary 600 500 400 W = 5.6% 2.7 fb (3 TeV) Observed Expected ± σ Expected ± 2σ 95% CL UL on σ 50 0 50 95% CL UL on σ 300 200 0 0 400 600 800 00 200 400 600 800 2000 Resonance Mass [GeV] 0 400 600 800 00 200 400 600 800 2000 Resonance Mass [GeV] 3.05.206 Clemens Lange - Diboson resonances searches at CMS 40