Measurements of the Higgs Boson Couplings and Other Properties at the LHC

Transcription

1 Measurements of the Higgs Boson Couplings and Other Properties at the LHC Marcello Fanti (on behalf of the ATLAS and CMS collaborations) University of Milano and INFN M. Fanti (Physics Dep., UniMi) Higgs boson at LHC ATLAS CMS / 37

2 Observation of a new particle July 4th, After the end of LHC run-i ATLAS, H γγ ATLAS, H ZZ 4l we have a discovery Events / GeV L dt = 4.5 fb, L dt =.3 fb Unweighted sum s = 7 TeV, s = 8 TeV ATLAS Data Signalbackground Background Signal Events/5 GeV Data SM Higgs Boson m H =4.3 GeV (fit) Background Z, ZZ* Background Zjets, tt Syst.Unc. ATLAS H ZZ* 4l s = 7 TeV Ldt = 4.6 fb s = 8 TeV Ldt =.7 fb 5 5 data - fitted bkg [GeV] m γγ m 4l [GeV] independent observations: ATLAS: combination of H γγ and H ZZ 4l CMS: combination of several decay channels CMS, H γγ CMS, H ZZ 4l Events / 3 GeV CMS s = 7 TeV, L = 5. fb ; s = 8 TeV, L = 9.7 fb 35 Data ZX * Zγ,ZZ m H =6 GeV (GeV) m 4l mass of the new particle 5 GeV M. Fanti (Physics Dep., UniMi) Higgs boson at LHC ATLAS CMS / 37

3 Higgs candidates : H γγ and H ZZ 4` H γγ candidate at CMS M. Fanti (Physics Dep., UniMi) H ZZ e e µµ candidate at ATLAS Higgs boson at LHC ATLAS CMS 3 / 37

4 Is it the Standard Model Higgs boson, indeed? If it is the Standard Model Higgs boson, its properties are: spin-parity : J CP = couplings to vector bosons : g V = m V υ couplings to fermions : g f = m f υ For a mass m H 5 GeV, several decay modes are kinematically accessible a thorough study of its properties is possible The LHC run ended in December Overall integrated luminosity : L dt 5 fb at s = 7 TeV L dt fb at s = 8 TeV ] Delivered Luminosity [fb ATLAS Online Luminosity pp pp pp s = 7 TeV s = 7 TeV s = 8 TeV ATLAS and CMS observed decays into γγ, ZZ, WW, τ τ 5 Jan Apr Jul Oct Month in Year can probe several couplings and J CP states Observation of H γγ C = and J (Landau-Yang theorem) M. Fanti (Physics Dep., UniMi) Higgs boson at LHC ATLAS CMS 4 / 37

5 Anatomy of the new particle M. Fanti (Physics Dep., UniMi) Higgs boson at LHC ATLAS CMS 5 / 37

6 Measurements: general strategy If it is the Higgs boson, its mass m H is the only free parameter of the model. needs precise measurement. σ(pp HX) [pb] pp HX at s=4 TeV pp HX at s=8 TeV pp HX at s=7 TeV LHC HIGGS XS WG Once m H is known, all the other properties are predicted by the Standard Model i i g i SM H ii H oo g o SM o o couplings to gauge bosons : g SM V couplings to fermions : g SM f = m f υ production cross-sections σ SM ii H branching ratios BR SM H oo total decay width Γ H differential cross-sections dσsm dp T we can test the Standard Model predictions on observed data = m V υ, dσsm dy,... Higgs BR Total Uncert M H [GeV] ττ cc bb M H [GeV] Γ H [GeV] γγ 3 gg Zγ WW ZZ tt LHC HIGGS XS WG LHC HIGGS XS WG 3 5 M H [GeV] M. Fanti (Physics Dep., UniMi) Higgs boson at LHC ATLAS CMS 6 / 37

7 Statistical models used in measurements Extended likelihood function: L( α; ν): ln L( α; ν) = (n s n b ) signal pdf background pdf {}}{{}}{ n s f s ( x e α, ν s ) n b f b ( x e ν b ) e ancillary pdfs { }}{ ln π k (ν k ) k n s, n b : signal / background yields x: observables f s, f b : signal / background pdfs α: parameters of interest (mass, cross-section, couplings,... ) ν: nuisance parameters (shape parameters, systematics,... ) π k : pdfs obtained from auxiliary measurements Test statistic: Profiled Likelihood Ratio (PLR) q α = ln Λ( α) = ln L( α; ˆν( α)) L(ˆα; ˆν) L( α; ˆν( α)): likelihood for fixed α and profiled ν L(ˆα; ˆν): maximum likelihood for free α, ν Wilks theorem : if α = α true, then q α follows a χ D distribution, with D being the number of parameters of interest α ln Λ % CL α 68% CL ln Λ <.3 95% CL ln Λ < 6. compute confidence intervals for α 68% CL α α M. Fanti (Physics Dep., UniMi) Higgs boson at LHC ATLAS CMS 7 / 37

8 Mass measurement Use the H γγ and H ZZ 4l decay channels that allow a full kinematics reconstruction with good invariant mass resolution (O ( GeV)) ATLAS CMS -lnλ ATLAS s = 7 TeV Ldt = 4.5 fb s = 8 TeV Ldt =.3 fb Combined γγ4l H γγ H ZZ* 4l without systematics σ - ln L CMS H γγ H ZZ µ, µ (ggh,tth), γγ µ (VBF,VH) γγ ZZ 9.7 fb (8 TeV) 5. fb (7 TeV) m H = 5. H γγ tagged H ZZ tagged Combined: stat. syst. stat. only (stat) (syst) m H [GeV] σ (GeV) m H ˆm H = 5.36 ±.37(stat) ±.8(syst) GeV ˆm H = 5. ±.7(stat) ±.5(syst) GeV (e, µ energy scales from J/ψ, Υ, Z ll ; γ energy scale from Z e e and e γ extrapolation) M. Fanti (Physics Dep., UniMi) Higgs boson at LHC ATLAS CMS 8 / 37

9 Mass measurement: ATLASCMS combination ) ln Λ(m H ATLAS LHC and CMS Run H γ γ H ZZ 4l Combined γ γ 4l Stat. only uncert [GeV] m H ATLAS H γ γ CMS H γ γ ATLAS H ZZ 4l CMS H ZZ 4l ATLASCMS γ γ ATLASCMS 4l ATLASCMS γ γ 4l Total Stat. Syst. ATLAS and CMS LHC Run [GeV] m H ˆm H = 5.9 ±.(stat) ±.(syst) GeV BUT : in the following, each experiment uses its own best ˆm H M. Fanti (Physics Dep., UniMi) Higgs boson at LHC ATLAS CMS 9 / 37

10 Measurements of the couplings M. Fanti (Physics Dep., UniMi) Higgs boson at LHC ATLAS CMS / 37

11 Higgs boson production at LHC Production mechanisms at LHC σ(pp HX) [pb] pp H (NNLONNLL QCD NLO EW) pp qqh (NNLO QCD NLO EW) pp WH (NNLO QCD NLO EW) pp ZH (NNLO QCD NLO EW) s= 8 TeV LHC HIGGS XS WG QCD production EW production pp tth (NLO QCD) [GeV] M H Experimental identification of VBF and VH productions ( tagging ): τ forward tag jet b-jet µ p p p p forward tag jet τ b-jet µ M. Fanti (Physics Dep., UniMi) Higgs boson at LHC ATLAS CMS / 37

12 Production via gg-fusion and via weak boson(s) Introduce cross-section modifiers: µ = σ BR σ SM BR SM (aka signal strengths ) split by QCD production (ggft th) and EW production (VBFVH): µ VBFVH probes HWW, HZZ vertices (EWSB) µ ggftth probes tth vertex (Yukawa coupling) VBFVH µ f Standard Model Best fit 68% CL 95% CL ATLAS Preliminary s = 7 TeV, fb s = 8 TeV,.3 fb * H WW * H ZZ H bb H γγ H ττ µ VBF,VH 6 4 CMS 9.7 fb (8 TeV) 5. fb (7 TeV) H γγ tagged H ZZ tagged H WW tagged H ττ tagged H bb tagged SM Higgs = 5.36 GeV m H µ f ggftth 3 µ ggh,tth (CAVEAT: need to account for contaminations across tagged categories) M. Fanti (Physics Dep., UniMi) Higgs boson at LHC ATLAS CMS / 37

13 Couplings Reminder: in SM Higgs couplings are g SM f = m f υ and g SM V = m V υ i o Couplings are accessible through production (ii H) and decay (H oo) Define couplings modifiers κ x = g x g SM x H SM κ i g i κ o g o SM σ ii H oo = σ SM ii H oo κ i κ o κ H i o (κ H = Γ H Γ SM H = o κ obr SM H oo) Several couplings: κ W, κ Z, κ t, κ b, κ τ... Assume weak gauge boson universality: κ W = κ Z = κ V and fermion universality: κ t = κ b = κ τ = κ f Loop-mediated interactions described as in SM: gg H (mainly) through top quark virtual loop κ g = κ t = κ f H γγ through top and W virtual loops κ γ = (.6 κ W.6 κ t ) = (.6 κ V.6 κ f ) M. Fanti (Physics Dep., UniMi) Higgs boson at LHC ATLAS CMS 3 / 37

14 (Universal) couplings to fermions and weak bosons measure κ V, κ f for each decay channel H γγ, H WW, H ZZ, H τ τ, H b b then combine decay channels κ F 4 3 ATLAS Prelim. s = 7 TeV, fb s = 8 TeV,.3 fb m H = 5.36 GeV κ f CMS 9.7 fb (8 TeV) 5. fb (7 TeV) Observed SM Higgs H WW H ZZ H γγ 95% C.L. H ττ H bb 3 4 SM Best fit 68% CL 95% CL H γγ * H ZZ * H WW H ττ H bb Combined κ V κ V all measurements compatible with SM prediction (κ V =, κ f = ) M. Fanti (Physics Dep., UniMi) Higgs boson at LHC ATLAS CMS 4 / 37

15 Relaxing some assumptions on couplings... Test the weak gauge boson universality: λ WZ = κ W κ Z - ln L CMS κ f, κ Z, λ WZ 9.7 fb (8 TeV) 5. fb (7 TeV) Observed Exp. for SM H.5.5 λ WZ Test the isospin universality for fermions: λ du = κ d κ u ( u / d refers to fermions isospin / ) and lepton/quark universality: λ lq = κ l κ q - ln L CMS λ du, κ u, κ V 9.7 fb (8 TeV) 5. fb (7 TeV) Observed Exp. for SM H - ln L CMS λ lq, κ q, κ V 9.7 fb (8 TeV) 5. fb (7 TeV) Observed Exp. for SM H λ du λ lq M. Fanti (Physics Dep., UniMi) Higgs boson at LHC ATLAS CMS 5 / 37

16 Tests on ggh and Hγγ interactions ggh and Hγγ interactions in SM are mediated by loops particularly sensitive to new particles in the loops consider κ g, κ γ as free and profile others κ g Standard Model Best fit 68% CL 95% CL ATLAS Preliminary s = 7 TeV, fb s = 8 TeV,.3 fb κ g CMS 9.7 fb (8 TeV) 5. fb (7 TeV) = 5.36 GeV m H κ γ Observed 68% CL 95% CL 99.7% CL SM Higgs.5..5 κ γ M. Fanti (Physics Dep., UniMi) Higgs boson at LHC ATLAS CMS 6 / 37

17 Summary of the couplings and signal strengths So far, none of the measurements shows discrepancies wrt Standard Model predictions / g f and /v) or (g λ f V CMS µ 68% CL 95% CL SM Higgs 9.7 fb (8 TeV) 5. fb (7 TeV) τ b (M, ε) fit W Z t 68% CL 95% CL. Particle mass (GeV) gv υ scale with m f, m V as expected! ATLAS Preliminary m H = 5.36 GeV H γγ H ZZ* H WW* H bb H ττ H µµ H Zγ Combined µ =.7 µ =.46 µ =.8 µ =.63 µ =.44 µ = -.7 µ =.7 µ =.8 s = 7 TeV, fb s = 8 TeV,.3 fb σ(stat.) sys inc. σ( theory σ(theory) ) Total uncertainty ± σ on µ 3 BUT : uncertainties are sizable! (stat, experimental syst, and theory) Signal strength (µ) M. Fanti (Physics Dep., UniMi) Higgs boson at LHC ATLAS CMS 7 / 37

18 Spin hypothesis test and parity measurements M. Fanti (Physics Dep., UniMi) Higgs boson at LHC ATLAS CMS 8 / 37

19 Spin/parity measurement H γγ: flat cos θ for spin-, sensitive to spin-...8 spin kq = kg kq = kq = kg H ZZ 4l: cosθ* H WW lνlν: W /W spin correlation spin l ν Arbitrary Normalisation.3. ATLAS Simulation, Preliminary s = 8 TeV (*) H WW eµ/µe jets H H [5] [5]. l H mw W W m ν H ν m W m l Arbitrary Normalisation. 3 ATLAS Simulation, Preliminary s = 8 TeV (*) H WW eµ/µe jets H H [5] [5] φ(ll) several angular observables m, m 34 sensitive to spin and parity ν l. sensitive to spin and parity m ll [GeV] M. Fanti (Physics Dep., UniMi) Higgs boson at LHC ATLAS CMS 9 / 37

20 Spin- tests Arbitrary normalization ATLAS Preliminary Data H ZZ* 4l s = 7 TeV, 4.5 fb s = 8 TeV,.3 fb H WW* eνµν s = 8 TeV,.3 fb H γγ s = 7 TeV, 4.5 fb s = 8 TeV,.3 fb log(l(h )/L(H )) / L ) P ln(l - J CMS X ZZ WW 9.7 fb (8 TeV) 5. fb (7 TeV) - Observed Expected ± σ P J ± σ ± σ P J ± σ ± 3σ P J ± 3σ m h h3 h b h6 h7 - h - h9 - h m h h3 h b h6 h7 - h - h9 - h qq gg production qq production data favour spin- M. Fanti (Physics Dep., UniMi) Higgs boson at LHC ATLAS CMS / 37

21 Parity and CP-mixing L V = X {cos α κ SM [ g HZZZ µ Z µ g HWW W µ W µ ] ] [cos α κ HZZ Z µν Z µν sin α κ AZZ Z µν Z µν 4Λ [cos α κ HWW W Λ µνw µν sin α κ AWW W µν W ] } µν Arbitrary normalization - ATLAS Preliminary ZZ* 4 l Data H s = 7 TeV, 4.5 fb s = 8 TeV,.3 fb H WW* eνµν s = 8 TeV,.3 fb Standard Model : α =, κ HVV =, κ AVV = Beyond SM : κ HVV CP-even, κ AVV CP-odd CP-mixing for α and α π log(l(h )/L(H )) - ln λ ATLAS Preliminary Combined Observed H WW* eνµν Observed H ZZ* 4l H ZZ* 4l s = 7 TeV, 4.5 fb s = 8 TeV,.3 fb H WW* eνµν s = 8 TeV,.3 fb - ln λ ATLAS Preliminary Combined Observed H WW* eνµν Observed H ZZ* 4l H ZZ* 4l s = 7 TeV, 4.5 fb s = 8 TeV,.3 fb H WW* eνµν s = 8 TeV,.3 fb κ HVV = υ 4Λ κ HVV κ AVV = υ 4Λ κ AVV κ 8 /κ HVV SM ( κ /κ ) tan α AVV SM κ HVV, κ AVV compatible with M. Fanti (Physics Dep., UniMi) Higgs boson at LHC ATLAS CMS / 37

22 Width measurement M. Fanti (Physics Dep., UniMi) Higgs boson at LHC ATLAS CMS / 37

23 Width measurement In Standard Model, the Higgs decay width is expected to be Γ H 4 MeV cannot measure it from the observed resonance width (experimental uncertainty O (GeV)) Use H ZZ ( ) 4l decays. Compare Higgs on-shell (gg H ZZ ) and off-shell (gg H ZZ) production cross-sections: σ gg H ZZ g ( ŝ=mh ) Hgg g HZZ ; σ gg H Γ H m ZZ g H ( ŝ=m Z ) Hgg (m Z ) g HZZ under specific assumptions on g Hgg, g HZZ, their ratio gives a measurement of Γ H (e.g. need to assume that g Hgg be completely described by SM loops and scale accordingly with partonic ŝ) Events / GeV CMS 9.7 fb (8 TeV) 5. fb (7 TeV) Events / 3 GeV Data ggvv ZZ qq ZZ ZX kin D bkg > m 4l (GeV) - lnl CMS 9.7 fb (8 TeV) 5. fb (7 TeV) 4l observed 4l expected lν 4l observed on-shell lν 4l H ZZ expected on-shell Combined ZZ observed Combined ZZ expected 95% CL 68% CL m 4l (GeV) Γ H (MeV) M. Fanti (Physics Dep., UniMi) Higgs boson at LHC ATLAS CMS 3 / 37

24 Differential cross-sections M. Fanti (Physics Dep., UniMi) Higgs boson at LHC ATLAS CMS 4 / 37

25 Extraction of signal yield per category... Events / GeV data - b ATLAS data sb fit background, b pp H γ γ, s = 8 TeV L dt =.3 fb = 5.4 GeV m H jet N jets =, p > 3 GeV T m γ γ [GeV] divide events in categories (e.g. number of jets, bins of p γγ T, bins of Y γγ, etc... ) from the invariant mass spectrum, extract the signal yield in each category / bin Events / GeV 8 6 ATLAS pp H γ γ, s = 8 TeV L dt =.3 fb = 5.4 GeV m H jet N jets =, p > 3 GeV T 4 data sb fit background, b data - b m γγ [GeV] m γ γ [GeV] Events / GeV ATLAS pp H γ γ, s = 8 TeV L dt =.3 fb = 5.4 GeV m H jet N jets =, p > 3 GeV T data - b data sb fit background, b m γγ [GeV] m γ γ [GeV] Events / GeV 8 6 ATLAS pp H γ γ, s = 8 TeV L dt =.3 fb = 5.4 GeV m H jet N jets 3, p > 3 GeV T data - b 4 - data sb fit background, b m γγ [GeV] m γ γ [GeV] then unfold the experimental effects (efficiencies, migrations,... ) get the cross-section per category / bin M. Fanti (Physics Dep., UniMi) Higgs boson at LHC ATLAS CMS 5 / 37

26 Differential cross-sections H γγ [fb/gev] / dp dσ fid T ATLAS data syst. unc. gg H (HRES) X H =.5) (K ggf X H = VBF VH tth H γ γ, s = 8 TeV L dt =.3 fb / d y [fb] dσ fid 6 ATLAS data syst. unc. H γ γ, s = 8 TeV gg H (HRES) X H 5 (K ggf =.5) L dt =.3 fb 4 3 X H = VBF VH tth [fb] σ fid ATLAS data syst. unc. gg H (MiNLO HJPY8) X H =.54) (K ggf X H = VBF VH tth H γ γ, s = 8 TeV L dt =.3 fb jet p > 3 GeV T data / prediction γ γ p [GeV] T data / prediction y γ γ data / prediction N jets H ZZ 4l [fb/gev] T / dp dσ fid ATLAS.6 data syst. unc. H ZZ* 4l gg H (MiNLO HJPS) X H s = 8 TeV L dt =.3 fb gg H (POWHEGPS) X H gg H (HRES) X H X H = VBF VH tth / d y [fb] dσ fid ATLAS 3.5 data syst. unc. H ZZ* 4l gg H (MiNLO HJPS) X H 3 s = 8 TeV L dt =.3 fb gg H (POWHEGPS) X H gg H (HRES) X H X H = VBF VH tth [fb] σ fid.8 ATLAS data syst. unc. H ZZ* 4l.6 gg H (MiNLO HJPS) X H s = 8 TeV L dt =.3 fb.4 gg H (POWHEGPS) X H jet p > 3 GeV T X H = VBF VH tth p T,H [GeV] y H 3 n jets N jets M. Fanti (Physics Dep., UniMi) Higgs boson at LHC ATLAS CMS 6 / 37

27 Summary M. Fanti (Physics Dep., UniMi) Higgs boson at LHC ATLAS CMS 7 / 37

28 The state of the art ATLAS and CMS have analysed all LHC run data. Strong evidence for H γγ, H ZZ 4l, H WW lνlν, H τ τ The new particle is compatible with a state J CP = several alternative states disfavoured to > 99% CL. All couplings measurements do not show any significant deviation from the Standard Model predictions but measurements of individual κ s are precise to % 3% affected by statistics, experimental effects, and theory uncertainties New results indicate that particle discovered at CERN is a Higgs boson CERN press release Geneva, 4 March 3. At the Moriond Conference today, the ATLAS and CMS collaborations at CERN s Large Hadron Collider (LHC) presented preliminary new results that further elucidate the particle discovered last year. [... ] The new particle is looking more and more like a Higgs boson [... ] It remains an open question, however, whether this is the Higgs boson of the Standard Model of particle physics, or possibly the lightest of several bosons predicted in some theories that go beyond the Standard Model. [... ] To characterize all of the decay modes will require much more data from the LHC. M. Fanti (Physics Dep., UniMi) Higgs boson at LHC ATLAS CMS 8 / 37

29 Perspectives at LHC run-ii LHC recently delivered st p-p collisions at 3 TeV we are back into the game! Run-II program (5 8) p-p collisions at s = 3 (4?) TeV σ H increases by a factor.3 (.6 at 4 TeV) Foreseen integrated lumi fb per experiment ( fb in 5?) with fb, more Higgs events than in run-i s [TeV] (and similar increase in backgrounds... ) σ(pp HX) [pb] pp H (NNLONNLL QCD NLO EW) pp qqh (NNLO QCD NLO EW) pp WH (NNLO QCD NLO EW) pp ZH (NNLO QCD NLO EW) pp bbh (NNLO and NLO QCD) pp tth (NLO QCD) = 5 GeV M H MSTW8 Presently, theory prediction are dominated by PDF and α S uncertainties, and QCD scales ( 7% 7% overall) Hard work ongoing from theorists on PDFs: more NNLO computations, more LHC processes introduced in the fits, better methodology. Also, Higgs partonic cross-section evaluated at N 3 LO. expect theory uncertainties to reduce sizably (down to 3%?) Some educated guesses With fb at 3 4 TeV: Precise measurements of H τ τ, observation of H b b, evidence of t th production With 3 fb at 4 TeV( ): Evidence of H µ µ, precision measurements of all individual κ s to % accuracy LHC HIGGS XS WG 4 M. Fanti (Physics Dep., UniMi) Higgs boson at LHC ATLAS CMS 9 / 37

30 More material M. Fanti (Physics Dep., UniMi) Higgs boson at LHC ATLAS CMS 3 / 37

31 Summary of the signal strengths ATLAS Preliminary m H = 5.36 GeV H γγ H ZZ* H WW* H ττ VH Vbb H µµ H Zγ tth s = 7 TeV, fb s = 8 TeV,.3 fb (GeV) m H.7 Overall: µ = ggf: µ = VBF: µ = WH: µ = ZH: µ = Overall: µ = ggftth: µ = VBFVH: µ = Overall: µ = ggf: µ = VBF: µ = VH: µ = Overall: µ = ggf: µ = VBFVH: µ = Overall: µ = WH: µ = ZH: µ = Overall: µ = Overall: µ = bb: µ = Multilepton: µ = γγ: µ = Input measurements ± σ on µ 4 Signal strength (µ) Combined µ =. ±.4 H γγ (untagged) H γγ (VBF tag) H γγ (VH tag) H γγ (tth tag) H ZZ (/-jet) H ZZ (-jet) H WW (/-jet) H WW (VBF tag) H WW (VH tag) H WW (tth tag) H ττ (/-jet) H ττ (VBF tag) H ττ (VH tag) H ττ (tth tag) H bb (VH tag) 9.7 fb (8 TeV) 5. fb (7 TeV) CMS p SM =.84 m H = 5 GeV H bb (tth tag) Best fit σ/σ SM So far, none of the measurements shows discrepancies wrt Standard Model predictions M. Fanti (Physics Dep., UniMi) Higgs boson at LHC ATLAS CMS 3 / 37

32 Expectations for 3 and 3 fb ATLAS Simulation Preliminary s = 4 TeV: Ldt=3 fb ; Ldt=3 fb H γγ H ZZ H WW H Zγ H bb H ττ H µµ (comb.) (comb.) (comb.) (incl.) (comb.) (VBF-like) (comb.)..4 µ/µ ATLAS Simulation Preliminary s = 4 TeV: Ldt=3 fb ; Ldt=3 fb H γγ H ZZ H WW H Zγ H bb H ττ H µµ (comb.) (j) (j) (VBF-like) (WH-like) (ZH-like) (tth-like) (comb.) (VH-like) (tth-like) (VBF-like) (ggf-like) (comb.) (j) (j) (VBF-like) (incl.) (comb.) (WH-like) (ZH-like) (VBF-like) (comb.) (incl.) (tth-like) µ/µ ATLAS Simulation Preliminary s = 4 TeV: Ldt=3 fb ; Ldt=3 fb κ gz λ WZ λ tg λ bz λ τz λ µz λ gz λ γz λ (Zγ)Z κ λ XY = ( κ X ) Y M. Fanti (Physics Dep., UniMi) Higgs boson at LHC ATLAS CMS 3 / 37

33 Expectations for 3 and 3 fb κ F.5 3 fb, w/ theory 3 fb, w/ theory fb, w/o theory 3 fb, w/o theory Standard Model ATLAS Simulation Preliminary s = 4 TeV κ V i y Ratio to SM ATLAS Simulation Preliminary h γγ, h ZZ* 4l, h WW* lνlν h ττ, h bb, h µµ, h Zγ [κ Z, κ W, κ t, κ b, κ τ, κ µ ] BR i,u = µ τ b s = 4 TeV W Ldt = 3 fb Z Ldt = 3 fb t [GeV] m i M. Fanti (Physics Dep., UniMi) Higgs boson at LHC ATLAS CMS 33 / 37

34 Expectations for 3 and 3 fb Expected uncertainties on κ at 3 fb and 3 fb. g g SM M. Fanti (Physics Dep., UniMi) Higgs boson at LHC ATLAS CMS 34 / 37

35 Higgs production at LHC M. Fanti (Physics Dep., UniMi) Higgs boson at LHC ATLAS CMS 35 / 37

36 Higgs decay modes M. Fanti (Physics Dep., UniMi) Higgs boson at LHC ATLAS CMS 36 / 37

37 Cross-sections at LHC M. Fanti (Physics Dep., UniMi) Higgs boson at LHC ATLAS CMS 37 / 37