Search for di-Higgs to 4b with the ATLAS detector 2016 Public (13 fb - - PowerPoint PPT Presentation

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Search for di-Higgs to 4b with the ATLAS detector 2016 Public (13 fb - - PowerPoint PPT Presentation

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Search for di-Higgs to 4b with the ATLAS detector 2016 Public (13 fb -1 ) and 2017 Expected (24/36 fb -1 ) Results Tony(Baojia)Tong, Harvard University DPF, Aug.2, 2016 Motivation Di-Higgs production A Beyond Standard Model Standard

slide-1
SLIDE 1

Search for di-Higgs to 4b with the ATLAS detector

Tony(Baojia)Tong, Harvard University DPF, Aug.2, 2016

2016 Public (13 fb-1) and 2017 Expected (24/36 fb-1) Results

slide-2
SLIDE 2

Aug 2, 2017

Tony Tong (Harvard)

  • A “Beyond Standard Model”

Standard Model process

  • Cross section small in SM:
  • 8 TeV ~ 10 fb (NNLO)
  • 13 TeV ~ 34 fb (NNLO + NNLL)

Motivation

2

Di-Higgs production

D.Florian,J.Mazzitelli, Arxiv1505.07122

slide-3
SLIDE 3

Aug 2, 2017

Tony Tong (Harvard)

  • Cross section small in SM:
  • 8 TeV ~ 10 fb
  • 13 TeV ~ 34 fb
  • Larger if BSM physics exists
  • Non-resonant Examples
  • tth vertex modifications
  • λhhh triple-Higgs coupling
  • Resonant Examples
  • KK Graviton
  • Heavy Higgs: 2HDM

Motivation

3

Di-Higgs production

slide-4
SLIDE 4

Aug 2, 2017

Tony Tong (Harvard)

  • Cross section small in SM:
  • 8 TeV ~ 10 fb
  • 13 TeV ~ 34 fb
  • Larger if BSM physics exists
  • Non-resonant Examples
  • tthh, tth vertex modifications
  • λhhh triple-Higgs coupling
  • Resonant Examples
  • KK Graviton, spin 2
  • Heavy Higgs: 2HDM, spin 0

Motivation

4

Di-Higgs production

(G/H) h h

slide-5
SLIDE 5

Aug 2, 2017

Tony Tong (Harvard)

Motivation

5

Di-Higgs decay

2e-3

larger branching ratio—higher yield

single Higgs decay single Higgs decay

h h b b

  • b

b

slide-6
SLIDE 6

Aug 2, 2017

Tony Tong (Harvard)

Motivation

6

Di-Higgs decay

4b better limit for higher mass

  • Phys. Rev. D 92, 092004 (2015)

2e-3

larger branching ratio—higher yield

single Higgs decay single Higgs decay

slide-7
SLIDE 7

Aug 2, 2017

Tony Tong (Harvard)

  • Standard resolved 4b jets for the low mass range

RunII 4b: object definition

7

Channels: Resolved

ATLAS-CONF-2016-049

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SLIDE 8

Aug 2, 2017

Tony Tong (Harvard)

  • Standard resolved 4b jets for the low mass range
  • 1.5 TeV resonance → ~ 600 GeV pT Higgs → ΔRbb ~2mh/pT ~ 0.4

RunII 4b: object definition

8

Channels: Resolved + Boosted

ATLAS-CONF-2016-049

trackjet

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SLIDE 9

Aug 2, 2017

Tony Tong (Harvard)

Objects/ Final State Resolved (250–1100 GeV) Boosted (1100-3000 GeV) Trigger Mixed b Trigger Large R-jet Trigger Jets Four 0.4 Anti-kt Jets Two 1.0 trimmed Anti-kt Jets pT cuts Jet pT > 40 GeV Leading > 450 GeV Subleading > 250 GeV B-tagging 70% on Jets 77% on R=0.2 trk jets

  • Standard resolved 4b jets for the low mass range
  • 1.5 TeV resonance → ~ 600 GeV pT Higgs → ΔRbb ~2mh/pT ~ 0.4

RunII 4b: object definition

9

Channels: Resolved + Boosted

ATLAS-CONF-2016-049

slide-10
SLIDE 10

Aug 2, 2017

Tony Tong (Harvard)

  • Select hh pair that has the minimal distance to a

diagonal line on the 2D mass plane

  • Minimize the Higgs candidates mass difference

RunII 4b: resolved selection

10

Resolved: Jets Pairing and Cuts

ATLAS-CONF-2016-049

which pair?

slide-11
SLIDE 11

Aug 2, 2017

Tony Tong (Harvard)

  • Select hh pair that has

the minimal distance to a diagonal line on the 2D mass plane

  • m4j dependent

requirements on h pT, eta, and dRjj

  • Fine signal efficiency

across large mass ranges

RunII 4b: resolved selection

11

Resolved: Jets Pairing and Cuts

ATLAS-CONF-2016-049

[GeV]

KK

G*

m

300 400 500 600 700 800 900 1000 1100 1200

Efficiency × Acceptance

0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 0.2

4 b-tagged jets

jj

R ∆

hh

R ∆ Dependent Cuts,

4j

m

hh

X Trigger

Preliminary ATLAS

Resolved

  • 1

= 13 TeV, 2016, 10.1 fb s

SMNR 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08

non-res

slide-12
SLIDE 12

Aug 2, 2017

Tony Tong (Harvard)

  • Three Signal Regions:
  • 4b
  • 3b: (recover

efficiency)

  • 2b split

(merging of trackjets)

RunII 4b: boosted selection

12

Boosted: Number of b-tagging

b b b b

slide-13
SLIDE 13

Aug 2, 2017

Tony Tong (Harvard)

  • Three Signal Regions:
  • 4b
  • 3b: (recover

efficiency)

  • 2b split

(merging of trackjets)

RunII 4b: boosted selection

13

Boosted: Number of b-tagging

b b b b

Mass [GeV] 1000 1500 2000 2500 3000 Acceptance x Efficiency 0.05 0.1 0.15 0.2 0.25 0.3 0.35

2 b-tagged track-jets 3 b-tagged track-jets 4 b-tagged track-jets All of above

ATLAS Internal

= 13 TeV s G c=1.0, Boosted

s

ATLAS work in

progress

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SLIDE 14

Aug 2, 2017

Tony Tong (Harvard)

RunII 4b: object definition

14

Regions: Two Higgs Mass Plane

  • Signal Region (SR):
  • “Circle” centered at h mass
  • Validation Region (VR) :
  • Ring outside SR (for validation)
  • Sideband (SB)
  • Ring outside VR (for modeling)

ATLAS-CONF-2016-049

50 100 150 200 [GeV]

lead J

m 50 100 150 200 250 [GeV]

subl J

m 50 100 150 200 250 ATLAS Preliminary

  • 1

=13 TeV, 13.3 fb s Boosted

SB VR SR

Boosted 2Tag Background Prediction

slide-15
SLIDE 15

Aug 2, 2017

Tony Tong (Harvard)

RunII 4b: object definition

15

Regions: Two Higgs Mass Plane

  • Signal Region (SR):
  • “Circle” centered at h mass
  • Validation Region (VR):
  • Ring outside SR (for validation)
  • Sideband (SB)
  • Ring outside VR (for modeling)

ATLAS-CONF-2016-049

50 100 150 200 [GeV]

lead J

m 50 100 150 200 250 [GeV]

subl J

m 50 100 150 200 250 ATLAS Preliminary

  • 1

=13 TeV, 13.3 fb s Boosted

SB VR SR

Boosted 2Tag Background Prediction

slide-16
SLIDE 16

Aug 2, 2017

Tony Tong (Harvard)

RunII 4b: object definition

16

Regions: Two Higgs Mass Plane

  • Signal Region (SR):
  • “Circle” centered at h mass
  • Validation Region (VR):
  • Ring outside SR (for validation)
  • Sideband Region (SB):
  • Ring outside VR (for modeling)

ATLAS-CONF-2016-049

50 100 150 200 [GeV]

lead J

m 50 100 150 200 250 [GeV]

subl J

m 50 100 150 200 250 ATLAS Preliminary

  • 1

=13 TeV, 13.3 fb s Boosted

SB VR SR

Boosted 2Tag Background Prediction

slide-17
SLIDE 17

Aug 2, 2017

Tony Tong (Harvard)

RunII 4b: background estimation

17

Background

ATLAS-CONF-2016-049

  • Background:
  • 90-85% qcd—data driven
  • 10-15% ttbar—MC
  • use lower-b-tag low-signal yield

region to model higher-b-tag regions

  • derive the normalization factor from

the Sideband, check in Validation

50 100 150 200 [GeV]

lead J

m 50 100 150 200 250 [GeV]

subl J

m 50 100 150 200 250 ATLAS Preliminary

  • 1

=13 TeV, 13.3 fb s Boosted

SB VR SR

Boosted 2Tag Background Prediction

slide-18
SLIDE 18

Aug 2, 2017

Tony Tong (Harvard)

  • Background:
  • 90-85% qcd—data driven
  • 10-15% ttbar—MC
  • Need shape and normalization

estimates for qcd events

  • derive the normalization factor from

the Sideband, check in Validation

RunII 4b: background estimation

18

Background

ATLAS-CONF-2016-049

4b N 4b SR/VR ???

SB VR SR

slide-19
SLIDE 19

Aug 2, 2017

Tony Tong (Harvard)

  • Background:
  • 90-85% qcd—data driven
  • 10-15% ttbar—MC
  • use lower-b-tag low-signal yield

region to model higher-b-tag regions

  • derive the normalization factor from

the Sideband, check in Validation

RunII 4b: background estimation

19

Background

ATLAS-CONF-2016-049

4b 0b N 4b SR/VR ~ N0b SR/VR

SB VR SR SB VR SR

slide-20
SLIDE 20

Aug 2, 2017

Tony Tong (Harvard)

  • Background:
  • 90-85% qcd—data driven
  • 10-15% ttbar—MC
  • use lower-b-tag low-signal yield

region to model higher-b-tag regions

  • derive the normalization factor from

the Sideband, check in Validation

RunII 4b: background estimation

20

Background

ATLAS-CONF-2016-049

4b 0b N 4b SR/VR = N4b SB / N0b SB * N0b SR/VR

SB VR SR SB VR SR

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SLIDE 21

Aug 2, 2017

Tony Tong (Harvard)

  • Final discriminant: m4j, four jets’s invariant mass; no significant excess observed

RunII 4b: resolved results

21

Signal Region: Resolved

Data 2015 2016 Obs 1231 3990 Exp 1189 ± 76 3860 ± 230

[GeV]

4j

m

200 400 600 800 1000 1200

Data/Bkgd

1 2

Events/10 GeV

1 −

10 1 10

2

10 Data Multijet t t 10 × G(300) 10 × G(800) 500 × SM hh Stat+Syst Uncertainty

Preliminary ATLAS

Signal Region: Resolved

  • 1

= 13 TeV, 2015, 3.2 fb s

[GeV]

4j

m

200 400 600 800 1000 1200

Data/Bkgd

1 2

Events/10 GeV

1 −

10 1 10

2

10

3

10 Data Multijet t t 10 × G(300) 10 × G(800) 500 × SM hh Stat+Syst Uncertainty

Preliminary ATLAS

Signal Region: Resolved

  • 1

= 13 TeV, 2016, 10.1 fb s

2015 2016

ATLAS-CONF-2016-049 *2015 and 2016 have different trigger selection due to different run conditions

slide-22
SLIDE 22

Aug 2, 2017

Tony Tong (Harvard)

  • Final discriminant: m2j, dijet invariant mass; no significant excess observed

RunII 4b: boosted results

22

Signal Region: Boosted

500 1000 1500 2000 2500 3000 3500

Events / 100 GeV

1 10

2

10

[GeV]

2J

m

500 1000 1500 2000 2500 3000 3500

Data / Bkgd

1 2 3 4

ATLAS Preliminary

  • 1

=13 TeV, 13.3 fb s Signal Region, Boosted 4-tag Data Multijet t t Stat+Syst 100 × G(2000)

500 1000 1500 2000 2500 3000 3500

Events / 100 GeV

1 10

2

10

3

10

[GeV]

2J

m

500 1000 1500 2000 2500 3000 3500

Data / Bkgd

1 2 3 4

ATLAS Preliminary

  • 1

=13 TeV, 13.3 fb s Signal Region, Boosted 3-tag Data Multijet t t Stat+Syst 100 × G(2000)

500 1000 1500 2000 2500 3000 3500

Events / 100 GeV

1 10

2

10

3

10

[GeV]

2J

m

500 1000 1500 2000 2500 3000 3500

Data / Bkgd

1 2 3 4

ATLAS Preliminary

  • 1

=13 TeV, 13.3 fb s Signal Region, Boosted 2-tag Data Multijet t t Stat+Syst 100 × G(2000)

4b 3b 2bs

Channel 2bs 3b 4b Obs 2813 671 32 Exp 2770 ± 130 596 ± 39 38 ± 9

ATLAS-CONF-2016-049

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SLIDE 23

Aug 2, 2017

Tony Tong (Harvard)

  • Resolved ( < 1 TeV) +

Boosted ( > 1 TeV) Limits

  • Non-Resonance limit:
  • 1 pb (1.3 pb expected)
  • μ ~ 29 (39 expected)

RunII 4b: limits

23

Combined Limits

[GeV]

KK

G*

m 500 1000 1500 2000 2500 3000 [fb] b b b b → hh →

KK

G* → pp σ 1 10

2

10

3

10

4

10

= 1.0

Pl

M Bulk RS, k/ Observed Limit (95% CL) Expected Limit (95% CL) σ 1 ± Expected σ 2 ± Expected

Resolved Boosted

ATLAS Preliminary

= 13 TeV s

  • 1

Ldt = 13.3 fb

∫

ATLAS-CONF-2016-049

slide-24
SLIDE 24

Aug 2, 2017

Tony Tong (Harvard)

  • 2017 current analysis

is almost done!

  • Resolved/Boosted

24/36 fb-1 Statistically Combined Limits

  • Non-Resonance limit:
  • 200 fb expected
  • μ ~ 19 expected

RunII 4b: new limits

24

New: Combined Expected Limits

[GeV]

KK

G*

m 500 1000 1500 2000 2500 3000 [fb] b b b b → hh →

KK

G* → pp σ 1 10

2

10

3

10

= 1.0

Pl

M Bulk RS, k/ Expected Limit (95% CL) σ 1 ± Expected σ 2 ± Expected

  • Exp. Resolved 2015
  • Exp. Resolved 2016
  • Exp. Boosted 4b
  • Exp. Boosted 3b
  • Exp. Boosted 2b

ATLAS work in progress

2016 Exp 2017 Exp

slide-25
SLIDE 25

Aug 2, 2017

Tony Tong (Harvard)

  • ATLAS hh → bbbb current

search results have been presented

  • So far no significant excess
  • bserved, 13 TeV non-

resonance limit at 1 pb

  • A new 2017 result is coming

soon! Stay tuned!

Summary

25

Conclusion

500 1000 1500 2000 2500 3000 3500

N Events

1 −

10 1 10

2

10

3

10

4

10

5

10 [GeV]

2J

m 500 1000 1500 2000 2500 3000 3500 Data / Bkgd 0.5 1 1.5 2

KS = 0 (Est-Obs)/Obs = 0.0; E=4252.8; O=4252.8

ATLAS Internal

  • 1

=13 TeV, 15+16, 36.1 fb s TwoTag; split; Signal; mHH; pole Data Multijet t t Stat+Syst RSG 2.0TeV * 30

ATLAS work in progress 2017 Boosted Expected 2Tag-split Signal Region

slide-26
SLIDE 26

Aug 2, 2017

Tony Tong (Harvard)

Back Up

26

Back up Slides

slide-27
SLIDE 27

Aug 2, 2017

Tony Tong (Harvard)

HH ATLAS Results

27

Run I non-res limit comparison

RunI non-res limits rel to SM Obs(Exp) bb𝜐𝜐 160 (130) WW*γγ 1150 (680) bbγγ 220 (100) bbbb 63 (63) Combination 70 (48)

  • Phys. Rev. D 92, 092004 (2015)
slide-28
SLIDE 28

Aug 2, 2017

Tony Tong (Harvard)

HH ATLAS Results

28

Summary of HH ATLAS Results

ATLAS Search Results 8TeV, fb-1 13TeV, fb-1 HL-LHC bbbb 20 3 / 13 prospect bb𝜐𝜐 20 prospect bbγγ 20 3 prospect WW*γγ 20 13 Combination 20

slide-29
SLIDE 29

Aug 2, 2017

Tony Tong (Harvard)

  • Given:
  • Simultaneous fit of μqcd, att to extract the normalization factors
  • All fits are independent

RunII 4b

29

Fit on Leading Jet Mass Distribution

60 80 100 120 140 160 180 200

Events / 20 GeV

20 40 60 80 100

Leading large-R jet mass [GeV]

60 80 100 120 140 160 180 200

Data / Bkgd

0.6 0.8 1 1.2 1.4

ATLAS Preliminary

  • 1

=13 TeV, 13.3 fb s Sideband Region, Boosted 4-tag Data Multijet t t Stat

60 80 100 120 140 160 180 200

Events / 20 GeV

200 400 600 800 1000 1200 1400 1600

Leading large-R jet mass [GeV]

60 80 100 120 140 160 180 200

Data / Bkgd

0.6 0.8 1 1.2 1.4

ATLAS Preliminary

  • 1

=13 TeV, 13.3 fb s Sideband Region, Boosted 3-tag Data Multijet t t Stat

60 80 100 120 140 160 180 200

Events / 20 GeV

1000 2000 3000 4000 5000 6000 7000 8000

Leading large-R jet mass [GeV]

60 80 100 120 140 160 180 200

Data / Bkgd

0.6 0.8 1 1.2 1.4

ATLAS Preliminary

  • 1

=13 TeV, 13.3 fb s Sideband Region, Boosted 2-tag Data Multijet t t Stat

4b 3b 2bs

ATLAS-CONF-2016-049

slide-30
SLIDE 30

Aug 2, 2017

Tony Tong (Harvard)

  • Kinematics dependence of μqcd is corrected by reweighting
  • Resolved: Njet distribution, leading Higgs candidate pT, subleading Higgs

candidate E

  • Boosted; leading Higgs candidate pT, leading track jet pT of the leading

Higgs candidate, leading track jet pT of the subleading Higgs candidate

  • Iterated reweighting is used such that the correlations are taken into

account.

RunII 4b

30

Reweighting Details

slide-31
SLIDE 31

Aug 2, 2017

Tony Tong (Harvard)

[GeV]

4j

m

200 400 600 800 1000 1200 1400

Data/Bkgd

1 2

Events/10 GeV

1 −

10 1 10

2

10

3

10

Data Multijet t t Fit to Tail Tail Up Tail Down

  • Stat. Uncertainty

Preliminary ATLAS

Control Region: Resolved

  • 1

= 13 TeV, 2015, 3.2 fb s

  • Good agreement in shape and normalization

RunII 4b

31

Control Region: Resolved

[GeV]

4j

m

200 400 600 800 1000 1200 1400

Data/Bkgd

1 2

Events/10 GeV

1 −

10 1 10

2

10

3

10

4

10

Data Multijet t t Fit to Tail Tail Up Tail Down

  • Stat. Uncertainty

Preliminary ATLAS

Control Region: Resolved

  • 1

= 13 TeV, 2016, 10.1 fb s

2015 2016

Obs 3995 12752 Exp 4021 ± 88 12970 ± 110

ATLAS-CONF-2016-049

slide-32
SLIDE 32

Aug 2, 2017

Tony Tong (Harvard)

  • Good agreement in shape and normalization

RunII 4b

32

Control Region: Boosted

500 1000 1500 2000 2500 3000 3500

Events / 100 GeV

1 10

2

10

[GeV]

2J

m

500 1000 1500 2000 2500 3000 3500

Data / Bkgd

0.5 1 1.5 2

ATLAS Preliminary

  • 1

=13 TeV, 13.3 fb s Control Region, Boosted 4-tag Data Multijet t t Stat+Syst

500 1000 1500 2000 2500 3000 3500

Events / 100 GeV

1 10

2

10

3

10

[GeV]

2J

m

500 1000 1500 2000 2500 3000 3500

Data / Bkgd

0.5 1 1.5 2

ATLAS Preliminary

  • 1

=13 TeV, 13.3 fb s Control Region, Boosted 3-tag Data Multijet t t Stat+Syst

500 1000 1500 2000 2500 3000 3500

Events / 100 GeV

1 10

2

10

3

10

4

10

[GeV]

2J

m

500 1000 1500 2000 2500 3000 3500

Data / Bkgd

0.5 1 1.5 2

ATLAS Preliminary

  • 1

=13 TeV, 13.3 fb s Control Region, Boosted 2-tag Data Multijet t t Stat+Syst

4b 3b 2bs

Obs 7200 1529 81 Exp 6954 ± 52 1507 ± 24 94.4 ± 5.8

ATLAS-CONF-2016-049

slide-33
SLIDE 33

Aug 2, 2017

Tony Tong (Harvard)

  • Signal uncertainty mainly

comes from b-tagging

  • Bkg uncertainty is

dominated by data driven validation region estimates

  • Background/QCD shape

uncertainty is also applied

RunII 4b

33

Uncertainties Countdown

Boosted % Resolved %

ATLAS-CONF-2016-049

slide-34
SLIDE 34

Aug 2, 2017

Tony Tong (Harvard)

  • ICHEP-Moriond

Limit Direct Comparison

RunII 4b

34

Limit Comparison

[GeV]

KK

G*

m 500 1000 1500 2000 2500 3000 [fb] b b b b → hh →

KK

G* → pp σ 1 10

2

10

3

10

4

10

= 1.0

Pl

M Bulk RS, k/ Observed Limit (95% CL) Expected Limit (95% CL) σ 1 ± Expected σ 2 ± Expected )

  • 1

Previous Obs. Limit (L = 3.2 fb )

  • 1

Previous Exp. Limit (L = 3.2 fb

Resolved Boosted

ATLAS Preliminary

= 13 TeV s

  • 1

Ldt = 13.3 fb

∫

ATLAS-CONF-2016-049

slide-35
SLIDE 35

Aug 2, 2017

Tony Tong (Harvard)

Run I 4b

35

Resolved and Boosted Results

400 600 800 1000 1200 1400 1600

Events / 20 GeV

2 4 6 8 10 12 14 16 18

ATLAS = 8 TeV s

  • 1

Ldt = 19.5 fb

∫

Signal Region Data Multijet t t Syst+Stat Uncertainty = 1.0

Pl

M G*(700), k/ 3 × = 1.0,

Pl

M G*(1000), k/

[GeV]

4j

m

400 600 800 1000 1200 1400 1600

Data / Bkgd

1 2 3 4 5

[GeV]

2J

m

600 800 1000 1200 1400 1600 1800 2000

Data / Bkgd

1 2 3 4 5

600 800 1000 1200 1400 1600 1800 2000

Events / 50 GeV

2 4 6 8 10 12

Signal Region Data Multijet t t Syst+Stat Uncertainty 2 × = 1.0,

Pl

M G*(1000), k/ 15 × = 1.0,

Pl

M G*(1500), k/

ATLAS = 8 TeV s

  • 1

Ldt = 19.5 fb

∫

Resolved Boosted

Sample Signal Region Yield Multijet 81.4 ± 4.9 t¯ t 5.2 ± 2.6 Z+jets 0.4 ± 0.2 Total 87.0 ± 5.6 Data 87 SM hh 0.34 ± 0.05 G∗

KK (500 GeV ), k/ ¯

MPl = 1 27 ± 5.9

Sample Signal Region Yield Multijet 23.5 ± 4.1 t¯ t 2.2 ± 0.9 Z+jets 0.14 ± 0.06 Total 25.7 ± 4.2 Data 34 G∗

KK (1000 GeV ), k/ ¯

MPl = 1 2.1 ± 0.6

  • Eur. Phys. J. C (2015) 75:412
slide-36
SLIDE 36

Aug 2, 2017

Tony Tong (Harvard)

RunI 4b

36

Combined Limit

[GeV]

KK

G*

m 600 800 1000 1200 1400 1600 1800 2000 ) [fb] b b b b → hh →

KK

G* → (pp σ 1 10

2

10

= 1.0

Pl

M Bulk RS, k/ Observed Limit (95% CL) Expected Limit (95% CL) σ 1 ± Expected σ 2 ± Expected

ATLAS

  • 1

Ldt = 19.5 fb

∫

= 8 TeV s

  • Eur. Phys. J. C (2015) 75:412
slide-37
SLIDE 37

Aug 2, 2017

Tony Tong (Harvard)

  • Extrapolation of

current 2016 results

  • Limit: -3.5 < λhhh <

11

HL-LHC 4b

37

Future Perspectives

SM HHH

λ /

HHH

λ 10 − 5 − 5 10 15 20 [fb] b b b b → hh → pp σ 200 400 600 800 1000

Non-resonant prediction Expected Limit (95% CL) σ 1 ± Expected σ 2 ± Expected

ATLAS Internal

  • 1

= 14 TeV, L = 3000 fb s

Preliminary ATLAS

  • 1

= 13 TeV, 2016, 10.1 fb s

ATLAS-CONF-2016-024