in Section The H ZZ 4l channel

Transcription

1

2 14 Events / 2 GeV Events - Fitted bkg ATLAS -1 s = 7 TeV Ldt = 4.8 fb -1 s = 8 TeV Ldt = 20.7 fb Data SM Higgs boson m =126.8 GeV (fit) H Bkg (4th order polynomial) H γ γ m γ γ [GeV] Figure 2: Invariant mass distribution of diphoton candidates after all selections of the inclusive analysis for the combined 7 TeV and 8 TeV data. The result of a fit to the data with the sum of a SM Higgs boson signal (with m H = 126.8GeVandfreesignalstrength)andbackground is superimposed. The residuals of the data with respect to the fitted background are displayed in the lower panel. Events / 3 GeV CMS Preliminary Section ), and the predicted signal contributions from Data the various production processes Additional interpretation of these Z+X results is presented 0.8 in Section s = 7 TeV, L = 5.1 fb -1 ; 5. 20The H ZZ 4l channel s = 8 TeV, L = 19.6 fb * Zγ,ZZ m H =126 GeV 15 Despite the small branching ratio, this channel provides good sensitivity to Higgs boson studies, e.g. to 0.4 the 10coupling to Z bosons, mainly because of the large 0.3 signal-to-background ratio. 0.2 Events 5 are required to have two pairs of same-flavour, 0.1 opposite-charge, isolated leptons: 4e, 2e2µ, 2µ2e, 4µ 0 0 (where80 final states 100 with 120 two140 electrons 160 and180 two muons are ordered by the flavour of the dilepton m 4l [GeV] pair with mass closest to the Z-boson mass). The largest background Figure comes 7: from continuum (Z ( ) /γ )(Z ( ) /γ )production, Distribution of the four-lepton reconstructed mass for th channels referred (left). to hereafter Points represent as ZZ. Important the data, contributions shaded histograms rep the unshaded arise also from histogram Z + jets theand signal t t production, expectation. where Distribution two of th versus of the thecharged four-lepton reconstructed candidates canmass come mfrom 4` (right) decayswith conto of hadrons with b-orc-quark content, misidentification 2 relative density of signal events for m = 126 GeV. The points sh -1 K D CMS preliminary

3 ATLAS m H = GeV H γ γ µ = ±0.23 ±0.15 ± Low p µ = 1.6 Tt -0.4 ± High p µ = 1.7 Tt -0.6 ± jet high mass (VBF) µ = ±0.6 VH categories µ = 1.3 ± 0.9 H ZZ* 4l VBF+VH-like categories Other categories µ = 1.43 µ = 1.2 µ = 1.45 H WW* lνlν ±0.33 ±0.17 ± cos θ* SpinNParity(Determina&on( 5/22/13( F.(Ceru4(LBNL(N(EPSNHEP(Stockolm((2013( ±0.35 ±0.21 ±0.21 ±0.12 σ(stat) σ(sys) σ(theo) CollinsNSopper(frame( sensi&ve(to(j( H(!(WW*(!(lνlν((Several( variables(sensi&ve(to(j P (( µ = µ = Analyzed(channels:( 0+1 jet ± jet VBF µ = ± 0.5 Comb. H γ γ, ZZ*, WW* (γγ(decay(angle(cos(θ * ±0.15 )(in( ±0.14 µ = ±0.11 llinsnsopper(frame( s = 7 TeV Ldt = fb s = 8 TeV Ldt = 20.7 fb -1 nsi&ve(to(j( Signal strength (µ) Δφ l(l((,(m l(l( (,(..( Combined(with(BoostedN DecisionNTree((BDT)( ( Total H(!(ZZ*(!4l:(Full(final(state( uncertainty ± reconstruc&on(sensi&ve(to(j 1σ µ P (( 2(masses((M Z1,M Z2 )((and(5( angles(( Combined(with(BDT(or(MatrixN ElementNbased(discriminant( D JP' Events / ATLAS s = 8 TeV H γγ L dt = 20.7 fb P + J = 0 Expected P + J = 0 Data Bkg. syst. uncertainty Events / ATLAS s = 8 TeV H γγ L dt = 20.7 fb -1 P + J = 2 Expected P + J = 2 Data Bkg. syst. uncertainty (f =0%) qq (WW*(!(lνlν((Several( riables(sensi&ve(to(j P (( cos θ* cos θ*

4 Coupling measurements at ILC Self-coupling Top Yukawa coupling Gauge Coupling Yukawa coupling SUSY ATLAS Simulation s = 14 TeV: H µµ tth,h µµ VBF,H ττ H ZZ VBF,H WW H WW VH,H γ γ tth,h γ γ VBF,H γγ -1 Ldt=300 fb ; -1 Ldt=3000 fb -1 Ldt=300 fb extrapolated from 7+8 TeV H γγ (+j) H γγ µ µ

5 Loss compensation 2 (90m) Loss compensation 1 (140m) Linac 1 (1008m) Injector Matching/splitter (31m) Matching/combiner (31m) Arc 1,3,5 (3142m) Arc 2,4,6 (3142m) Bypass (230m) Linac 2 (1008m) Matching/combiner (31m) IP line Matching/splitter (30m) Detector parameter [unit] LHeC species e p, 208 Pb 82+ beam energy (/nucleon) [GeV] , 2760 bunch spacing [ns] 25, , 100 bunch intensity (nucleon) [10 10 ] 0.1 (0.2), (22), 2.5 beam current [ma] 6.4 (12.8) 860 (1110), 6 rms bunch length [mm] polarization [%] 90 none, none normalized rms emittance [µm] (2.0), 1.5 geometric rms emittance [nm] (0.31) IP beta function x,y [m] 0.12 (0.032) 0.1 (0.05) IP spot size [µm] 7.2 (3.7) 7.2 (3.7) synchrotron tune Q s hadron beam-beam parameter (0.0002) lepton disruption parameter D 6(30) crossing angle 0(detector-integrateddipole) hourglass reduction factor H hg 0.91 (0.67) pinch enhancement factor H D 1.35 CM energy [TeV] 1300, 810 luminosity / nucleon [10 33 cm 2 s 1 ] 1(10),0.2 5

6 High"energy"fronCer"DIS:"Higgs,"RPV"SUSY/LQ,"ewk"+"QCD"precision"physics,"low"x" With"the"LHC:"~10 34 cm`2 s`1 "in"ep,"4"orders"of"magnitude"in"1/x"in"ea,"half"ep"exists." 6

7 ! (fb) M H = 120GeV p e q W W H ν e q b _ b CC NC E e 10 (GeV) 7

8 Background (example) NOTE: numbers are after pre-selection in generator CC: H bb (BR ~ 0.7 at M H =120GeV) CC: 3 jets (~57pb) CC: single top production (~4.1pb) σb~ 0.16 pb at s=2.05tev CC: Z production (~0.11pb) NC: b pair production (~1.1nb) NOTE: The plots shown are from initial study for LHeC CDR ( ), Ee = 150GeV. Results also given for 60GeV (see later). 8 9

9 Event generation SM Higgs production CC & NC background by MadGraph/MadEvent Fragmentation Hadronization by Pythia (+ mod. for ep) Fast detector simulation by PGS n n n n n H bb selection n 109

10 Event generation SM Higgs production CC & NC background by MadGraph/MadEvent Fragmentation Hadronization by Pythia (+ mod. for ep) Fast detector simulation by PGS H bb selection 10 11

11 b-tag efficiency model for η < 3 b-jet identification: ε= 60% c-jet mis-id: ε= 10% Other jet mis-id: ε= 1% H bb CC BG NC BG

12 44% of remaining BG is single-top H bb CC BG NC BG 10% mis-id 12 14

13 13 15 H bb CC BG NC BG

14 H bb signal Coordinate: z-axis along proton beam H bb CC BG NC BG 17 14

15 Di-jet invariant mass after all selection Z bb background H bb CC BG NC BG

16 Signal and background cut flow H bb CC DIS NC bbj S/N S/ N NC rejection + b-tag requirement + Higgs invariant mass All cuts

17 /10GeV -1 Events/10fb Higgs + background CC background NC bbj background (GeV) M jj,h H bb signal S/N S/ N E e = 150 GeV (10 fb -1 ) E e = 60 GeV (100 fb -1 )

18 CP CP W W H 18

19 p e W W H q ν e q b _ b Normalised Cross section/bin [arb.unit] SM λ= +1 ; λ = 0 λ= 1 ; λ = 0 λ= 0 ; λ = +1 λ= 0 ; λ = 1 E e = 140 GeV Δφ [rad] MET J 19

20 λ Excluded at 95% C.L. - e p ν H + X, E e =140 GeV CP even coupling λ Excluded at 95% C.L. - e p ν Hq + X, E =140 GeV e CP odd coupling Excluded at 95% C.L Excluded at 95% C.L Integrated Luminosity [fb ] Integrated Luminosity [fb ] 20

21 21

22 Figure 3: NNLO calculation of the Higgs production cross section in pp scattering at the design LHC energy the ihixs program. The cross section is calculated at a scale of M H /2. The bands on the left side represe uncertainties of the various PDF sets available to NNLO as marked. The PDF4LHC convention excludes AB JR09VF, HERA and extreme values of s arriving in this calculation to roughly 5 % uncertainty from PDF vari to which one would add an about 10 % from scale uncertainty, as this picture looks di erent when M H is use text, and about 5 % due to s. The full experimental uncertainty estimated with the LHeC PDFs, as detailed CDR and plotted at the right column, is about 0.3 %, with a similar uncertainty to be added from 22 s discussed a

23 23

24 24

25 (backup) v2 1. It is required that MET > 25 GeV. 2. Presence of two b-partons with p b T > 30 GeV and η b < 2.5. The invariant mass of these b-partons must lie within 10 GeV of the Higgs boson mass. 3. Of the remaining partons, the leading one must have p T > 30 GeV and 1 < η < 5. This will be called the forward tagging parton. 4. We require ϕ MET J > 0.2 rad for all the jets (J). 5. A veto on leptons (l = e, µ, τ) with p l T and η l < 2.5 is required. > 10 GeV 6. The invariant mass of the Higgs boson candidate and the forward tagging jet must be greater than 250 GeV. 7. b-tagging efficiency: ε b =0.6 for η b < 2.5. The mis-tagging factor for c and light quark jets is taken as 0.1 and 0.01 respectively. 25

26 CC: H bb (BR ~ 0.7 at M H =120GeV) p T H η H σb~ 0.16 pb at s=2.05tev y JB Q 2 JB NOTE: The plots shown are from initial study for LHeC CDR ( ) using Ee = 150GeV. Results also given for 60GeV (see later). 26 8

27 H bb CC BG NC BG 27 12

28 28 16 H bb CC BG NC BG