M easurement of Higgs boson proper tj es at ti e LHC - Secrets of - - PowerPoint PPT Presentation

SLIDE 1

Measurement of Higgs boson propertjes at tie LHC

• Secrets of the LHC !? -

Reisaburo Tanaka (LAL, Orsay, ATLAS) February 11, 2015 HPNP2015, Toyama, Japan

SLIDE 2

• 1. Higgs boson mass (MH) & decay width (ΓH)
• 2. Higgs couplings to gauge bosons (gV) and fermions (gF)
• 3. Higgs boson quantum numbers JPC and tensor structure
• 4. Higgs potential - Higgs self-coupling (λ)

Higgs Boson Property Measurements

2

• K. Cranmer

The Standard Model Lagrangian - Higgs sector

Couplings to EW gauge bosons Higgs self-couplings Couplings to fermions

−

• f

mf ¯ ff

• 1 + h

v

• −i mf

v

2i m2

V

v gµν

−3i m2

H

v

−3i m2

H

v2

The ultimate goal of particle physics of today is to fix the Standard Model (SM) Lagrangian and find the physics beyond the Standard Model (BSM).

LSM = DµH†DµH + µ2H†H − λ

2

• H†H

2 −

• yijH ¯

ψiψj + h.c.

• m2

W W µ+W − µ + 1 2m2 ZZµ0Z0 µ

• ·
• 1 + h

v

2

−µ2h2 − λ

2 vh3 − 1 8λh4

mH = √ 2µ = √ λv (v = vacuum expectation value)

SLIDE 3

• 1. Higgs Boson Mass in H→γγ

MH - the only parameter not fixed in the Standard Model Most precisely determined with H→γγ and 4 lepton channels. ATLAS: MHγγ = 125.98 ± 0.42 (stat.) ± 0.28 (syst.) = 125.98 ± 0.50 GeV CMS: MHγγ = 124.70 ± 0.31 (stat.) ± 0.15 (syst.) = 124.70 ± 0.34 GeV

3

➭ Fixes .

λ = M2

H

v2

[GeV]

γ γ

m 110 120 130 140 150 160

weights - fitted bkg

∑

• 8
• 6
• 4
• 2

2 4 6 8

weights / GeV

∑

20 40 60 80 100 120 140 160 180 200

Data Combined fit: Signal+background Background Signal = 7 TeV s

• 1

Ldt = 4.5 fb

∫

= 8 TeV s

• 1

Ldt = 20.3 fb

∫

s/b weighted sum Mass measurement categories

ATLAS

SLIDE 4

Higgs Boson Mass in H→4l

Sophisticated 2D analysis with BDT (ATLAS) or Kin. Discrim. Variable (CMS).

4

[GeV]

l 4

m

• utput

ZZ*

BDT 0.02 0.04 0.06 0.08 0.1

• 1
• 0.5

0.5 1 110 115 120 125 130 135 140

Data = 1.66) µ = 124.5 GeV

H

Signal (m Background ZZ*, Z+jets

l 4 → ZZ* → H

• 1

Ldt = 4.5 fb

∫

= 7 TeV: s

• 1

Ldt = 20.3 fb

∫

= 8 TeV: s

ATLAS

SLIDE 5

Detector Calibration in e/γ/µ

Low pT leptons down to 5-7GeV/c are very important in H→4l. ATLAS spent 1-year for detector calibration in ECAL(e/γ) and muon. Below few per mille calibration !

5

• f the leading muon

η

• 2
• 1

1 2

MC µ µ

/ m

Data µ µ

m 0.995 0.996 0.997 0.998 0.999 1 1.001 1.002 1.003 1.004 1.005 ATLAS

CB muons =8 TeV s Data 2012,

• 1

L dt = 20.3 fb

∫

µ µ → Z µ µ → Υ µ µ → ψ J/

[GeV]

T

E 10 20 30 40 50 60 70 80 90 100 Scale Δ

• 0.02
• 0.015
• 0.01
• 0.005

0.005 0.01 0.015 0.02

• e

+

e → ψ J/

• e

+

e → Z Calibration uncertainty

|<0.60 η Electrons, | ATLAS

• 1

=20.3 fb t d L

∫

=8 TeV, s

pT of leptons in H→ZZ*→4l

SLIDE 6

Higgs Boson Mass in H→4l

No significant mass difference between H→γγ and 4 lepton channels. ATLAS spent 1-year for detector calibration in ECAL(e/γ) and muon.

6

[GeV]

l 4

m 80 90 100 110 120 130 140 150 160 170 Events / 2.5 GeV 5 10 15 20 25 30 35

Data = 1.66) µ = 124.5 GeV

H

Signal (m Background ZZ* t Background Z+jets, t Systematic uncertainty

l 4 → ZZ* → H

• 1

Ldt = 4.5 fb

∫

= 7 TeV: s

• 1

Ldt = 20.3 fb

∫

= 8 TeV: s

ATLAS

ATLAS: MH4l = 124.51 ± 0.52 (stat.) ± 0.06 (syst.) = 124.51 ± 0.52 GeV CMS: MH4l = 125.59 ± 0.42 (stat.) ± 0.17 (syst.) = 125.59 ± 0.45 GeV

SLIDE 7

Mass difference in H→4l channels

No significant mass difference among 4 lepton channels.

7

[GeV]

H

m Λ

• 2ln

2 4 6 8 10 12 14 121 123 125 127 129

4e µ 4 µ 2e2 2e µ 2 Combined

σ 1 σ 2

ATLAS

l 4 → ZZ* → H

• 1

Ldt = 4.5 fb

∫

= 7 TeV: s

• 1

Ldt = 20.3 fb

∫

= 8 TeV: s

Dashed without systematics Dashed without systematics

SLIDE 8

Combined Higgs Boson Mass

MH - the only parameter not fixed in the Standard Model Most precisely determined with H→γγ and 4 lepton channels. δMH precision below 0.3% level (PDG2014: δMW~190ppm, δMZ~23ppm, δMtop~0.5%). ATLAS: MH = 125.36 ± 0.37 (stat.) ± 0.18 (syst.) = 125.02 ± 0.41 GeV CMS: MH = 125.02 ± 0.27 (stat.) ± 0.15 (syst.) = 125.02 ± 0.30 GeV

8

➭ Fixes .

λ = M2

H

v2

[GeV]

H

m 123 123.5 124 124.5 125 125.5 126 126.5 127 127.5 )

=125.36 GeV)

H

(m

SM

• /
• Signal yield (

0.5 1 1.5 2 2.5 3 3.5 4

ATLAS

• 1

Ldt = 4.5 fb

• = 7 TeV

s

• 1

Ldt = 20.3 fb

• = 8 TeV

s

+ZZ*

• Combined
• H

l 4

• ZZ*
• H

Best fit 68% CL 95% CL

(GeV)

H

m

123 124 125 126 127

SM

• /
• 0.0

0.5 1.0 1.5 2.0 2.5

Combined tagged

• H

ZZ tagged

• H

CMS

(7 TeV)

• 1

(8 TeV) + 5.1 fb

• 1

19.7 fb

ZZ

• + H
• H

SLIDE 9

[GeV]

H

m 123 123.5 124 124.5 125 125.5 126 126.5 127 127.5 Λ

• 2ln

1 2 3 4 5 6 7

σ 1 σ 2

ATLAS

• 1

Ldt = 4.5 fb

∫

= 7 TeV s

• 1

Ldt = 20.3 fb

∫

= 8 TeV s

l +4 γ γ Combined γ γ → H l 4 → ZZ* → H without systematics

(GeV)

H

m

123 124 125 126 127

ln L Δ

• 2

1 2 3 4 5 6 7 8 9 10

tagged γ γ → H ZZ tagged → H Combined:

• stat. + syst.
• stat. only

CMS

(7 TeV)

• 1

(8 TeV) + 5.1 fb

• 1

19.7 fb

ZZ → + H γ γ → H

(ggH,ttH),

γ γ

µ ,

ZZ

µ (VBF,VH)

γ γ

µ (syst)

• 0.15

+0.14

(stat)

• 0.27

+0.26

= 125.02

H

m

Higgs Boson Mass Difference

No significant mass difference between H→γγ and 4 lepton channels. Opposite difference between ATLAS and CMS (with opposite color ...). Future: observation in mass difference in ΔMH(γγ-4l), ΔMH(ggF-VBF) in γγ, ATLAS: ΔMH(γγ-4l) = +1.47 ± 0.67 (stat.) ± 0.28 (syst.) GeV (1.98σ) CMS: ΔMH(γγ-4l) = -0.89 ± 0.57 GeV (1.6σ)

9

SLIDE 10

Future Improvements?

Ultimate goal: ΔMH < 50 MeV Reductions of experimental systematic uncertainties. Source of systematics between ATLAS and CMS are different. ATLAS: iLq. Ar front-material, cell non-linearity, layer calibration, EM shower lateral shape, ID material, Z→ee calibration, etc.

10

SLIDE 11

• 2. Higgs Boson Width
• 1. Via direct measurements

CMS H→γγ, 4l mass spectrum ΓH < 1.7 (2.3)GeV at 95% C.L.

• 2. Via Higgs coupling or invisible Higgs search

BR(inv)<50% limit corresponds to ΓH < 2ΓHSM (= 8MeV)

assuming couplings to SM particles are as in the SM.

• 3. Via Higgs interferometry

Destructive interference between Higgs signal and gg→VV continuum background.

H→γγ (S. Martin, L. Dixon) - mass shift (depends on Higgs pT) ΔMγγ = -70MeV for SM at NLO.

H→WW*/ZZ* (N. Kauer, G. Passarino) - mass spectrum in high-mass end above M4l > 2Mtop.

Sensitivity on ΔΓH ≲ O(100MeV) is feasible?

[GeV]

H

M 100 200 300 1000 [GeV]

H

• 2

10

• 1

10 1 10

2

10

3

10

LHC HIGGS XS WG 2010

500

11

CMS-HIG-14-009

ΓSM

H

= 4 MeV for MH = 125 GeV

SLIDE 12

Destructive interference between Higgs signal and continuum background. H→γγ (S. Martin, L. Dixon) Mass shift (depends on Higgs pT, maybe already interesting with 2-bin analysis.) ΔMγγ = -120MeV at LO and -70MeV at NLO for SM.

Higgs Interferometry in H→γγ

12

5 10 15 20 400 300 200 100 100 200 300 HH

SM

MH MeV Constructive Interf. Destructive Interf. SM

Dixon, Li 2013

H→γγ SM

g g t, b H γ γ W, t b, c, τ · · · b, c, . . . u, c, d, s, b · · · ∗ 20 40 60 80 100 120 100 80 60 40 20 20 pT,H GeV MH MeV Hgq OΑS

3

Hgq OΑS

3OΑS 2

Hg OΑS

3

SLIDE 13

Destructive interference between Higgs signal and continuum background. H→γγ (S. Martin, L. Dixon), Mass shift (depends on Higgs pT) ΔMγγ = -120MeV at LO and ΔMγγ = -70MeV at NLO for SM. No experimental results yet. Takes time ...

Higgs Interferometry in H→γγ

13

SLIDE 14

• Kauer-Passarino-Caola-Melnikov Effect
• Off-shell signal is independent of ΓH !
• On-shell signal XS is proportional to 1/ΓH
• Take the ratio !

Higgs Interferometry in H→4l

14

5 10 15 20 25 30 124.99 124.995 125 125.005 125.01 MZZ [GeV]

gg → H → ZZ → ℓ¯ ℓνℓ¯ νℓ, MH=125GeV pp, √s = 8TeV gg2VV

dσ/dMZZ [fb/GeV] |H+cont|2 Hoffshell HZWA

No interference effect for on-shell

SLIDE 15

Higgs Interferometry or Higgs offshell coupling 15

[GeV]

T

m 400 500 600 700 Events / 30 GeV 5 10 15 20 25

Preliminary

ATLAS

ν 2 e 2 → ZZ → H

• 1

Ldt = 20.3 fb

∫

= 8 TeV: s

Data ) ZZ → (H* → gg+VBF ZZ → q q WZ )+jets µ µ ee/ → Z( τ τ → WW/Top/Z Other backgrounds =10)

• ff-shell

µ All contributions ( Stat.+syst. uncertainties

[GeV]

4l

m 300 400 500 600 700 800 900 1000 Events / 30 GeV 10 20 30 40 50 60 70

Data ) ZZ → (H* → gg+VBF ZZ → q Background q t Background Z+jets, t =10)

• ff-shell

µ All contributions (

Preliminary

ATLAS

l 4 → ZZ → H

• 1

Ldt = 20.3 fb

∫

= 8 TeV: s

SLIDE 16

Higgs Interferometry or Higgs offshell coupling

• Quasi-equivalent sensitivity in H→4l and llνν
• Quasi-equivalent results in ATLAS and CMS
• ΓH<23(35)MeV (ATLAS), ΓH<22(33)MeV (CMS)

➭Interpretation is rather in term of off-shell coupling. 16

H SM

Γ /

H

Γ 2 4 6 8 10 12 14 Λ

• 2ln

2 4 6 8 10 12 14

Preliminary

ATLAS

combined

• n-shell

l +4 l +4 ν 2 l 2

• 1

Ldt = 20.3 fb

∫

= 8 TeV: s

expected with syst. expected no syst.

• bserved

SLIDE 17

SM

σ / σ Best fit

0.5 1 1.5 2

0.44 ± = 0.84 µ

bb tagged → H

0.28 ± = 0.91 µ

tagged τ τ → H

0.21 ± = 0.83 µ

WW tagged → H

0.29 ± = 1.00 µ

ZZ tagged → H

0.24 ± = 1.12 µ

tagged γ γ → H

0.14 ± = 1.00 µ

Combined

CMS

(7 TeV)

• 1

(8 TeV) + 5.1 fb

• 1

19.7 fb

= 125 GeV

H

m

= 0.96

SM

p

) µ Signal strength (

• 0.5

0.5 1 1.5 2

ATLAS Prelim.

• 1

Ldt = 4.6-4.8 fb

∫

= 7 TeV s

• 1

Ldt = 20.3 fb

∫

= 8 TeV s

= 125.5 GeV

H

m

0.28

• 0.33

+

= 1.57 µ γ γ → H

0.12

• 0.17

+ 0.18

• 0.24

+ 0.22

• 0.23

+

0.35

• 0.40

+

= 1.44 µ 4l → ZZ* → H

0.10

• 0.17

+ 0.13

• 0.20

+ 0.32

• 0.35

+

0.29

• 0.32

+

= 1.00 µ ν l ν l → WW* → H

0.08

• 0.16

+ 0.19

• 0.24

+ 0.21

• 0.21

+

0.20

• 0.21

+

= 1.35 µ

, ZZ*, WW* γ γ → H Combined

0.11

• 0.13

+ 0.14

• 0.16

+ 0.14

• 0.14

+

0.6

• 0.7

+

= 0.2 µ b b → W,Z H

<0.1 0.4 ± 0.5 ±

0.4

• 0.5

+

= 1.4 µ

(8 TeV data only)

τ τ → H

0.1

• 0.2

+ 0.3

• 0.4

+ 0.3

• 0.3

+

0.32

• 0.36

+

= 1.09 µ

τ τ , b b → H Combined

0.04

• 0.08

+ 0.21

• 0.27

+ 0.24

• 0.24

+

0.17

• 0.18

+

= 1.30 µ

Combined

0.08

• 0.10

+ 0.11

• 0.14

+ 0.12

• 0.12

+

Total uncertainty µ

• n

σ 1 ±

(stat.) σ

)

theory sys inc.

(

σ (theory) σ

• 3. The signal strength

Consistent with the SM prediction for both ATLAS and CMS with precision about 15% level. Theory uncertainty (QCD scale ±8%@NNLO and PDF+αs ±8%) is comparable to experimental and statistical uncertainties on the combined signal strength.

17

ATLAS-CONF-2014-009 CMS-HIG-14-009

µ = σ · BR (σ · BR)SM Winter 2014 RUN-1 Final

2.3σ 74% corr.

RUN-1 Final (still to come!)

?

SLIDE 18

ggH,ttH

µ

• 1

1 2 3

VBF,VH

µ

2 4 6

tagged γ γ → H ZZ tagged → H WW tagged → H tagged τ τ → H bb tagged → H SM Higgs

CMS

(7 TeV)

• 1

(8 TeV) + 5.1 fb

• 1

19.7 fb

ggF+ttH

µ /

VBF

µ

• 0.5

0.5 1 1.5 2 2.5 3 3.5 Λ

• 2 ln

2 4 6 8 10 12 14 16 18 20 22 24

combined SM expected

Preliminary ATLAS

• 1

Ldt = 4.6-4.8 fb

∫

= 7 TeV s

• 1

Ldt = 20.3 fb

∫

= 8 TeV s

= 125.5 GeV

H

m

ggH,ttH

µ /

VBF,VH

µ

0.5 1 1.5 2 2.5 3 3.5 4

ln L Δ

• 2

1 2 3 4 5 6 7 8 9 10

Observed

• Exp. for SM H

CMS

(7 TeV)

• 1

(8 TeV) + 5.1 fb

• 1

19.7 fb

Evidence for vector-boson-fusion process

18 4.1σ evidence

CMS-HIG-14-009 ATLAS-CONF-2014-009

τ τ ,ZZ*,WW*, γ γ ggF+ttH

µ

• 2
• 1

1 2 3 4 5 6

τ τ ,ZZ*,WW*, γ γ VBF+VH

µ

• 2

2 4 6 8 10

Standard Model Best fit 68% CL 95% CL γ γ → H 4l → ZZ* → H ν l ν l → WW* → H τ τ → H

Preliminary ATLAS

• 1

Ldt = 4.6-4.8 fb

∫

= 7 TeV s

• 1

Ldt = 20.3 fb

∫

= 8 TeV s

= 125.5 GeV

H

m

SLIDE 19

=125 GeV

H

for m

SM

σ / σ = µ best fit

• 1

1 2 3 4 5 6 7

Combination WH ZH

0.51 0.37

− 0.40 +

(

0.22 − 0.30 − 0.25 + 0.31 +

) 1.11 0.61

− 0.65 +

(

0.38 − 0.48 − 0.42 + 0.50 +

) 0.05 0.49

− 0.52 +

(

0.25 − 0.42 − 0.27 + 0.44 +

) tot ( stat syst )

tot. stat.

ATLAS

• 1

Ldt=20.3 fb

∫

=8 TeV, s ;

• 1

Ldt=4.7 fb

∫

=7 TeV, s

Evidence for Yukawa (湯川) Interaction

19

ln(1+S/B) w. Events / 10 GeV

20 40 60 80

[GeV]

τ τ MMC

m 50 100 150 200

Weighted (Data-Bkg.)

10 20

=1.0) µ ( (125) H =1.0) µ ( (110) H =1.0) µ ( (150) H

Data =1.0) µ ( (125) H τ τ → Z Others Fakes Uncert.

ATLAS VBF+Boosted τ τ → H

• 1

, 4.5 fb

= 7 TeV s

• 1

, 20.3 fb

= 8 TeV s ATLAS-HIGG-2013-32

) µ Signal strength (

2 4

ATLAS

• 1

= 7 TeV, 4.5 fb s

• 1

= 8 TeV, 20.3 fb s

= 125.36 GeV

H

m

0.4

• 0.4

+

= 1.4 µ

τ τ → H

0.1

• 0.1

+ 0.2

• 0.3

+ 0.3

• 0.3

+ 0.8

• 0.9

+

= 2.1 µ

Boosted

0.5

• 0.5

+ 0.4

• 0.4

+

= 1.2 µ

VBF

0.3

• 0.3

+ 1.1

• 1.1

+

= 0.9 µ

7 TeV (Combined)

0.8

• 0.8

+ 0.4

• 0.5

+

= 1.5 µ

8 TeV (Combined)

0.3

• 0.3

+ 0.9

• 1.0

+

= 2.0 µ

lep

τ

lep

τ → H

0.1

• 0.1

+ 0.5

• 0.6

+ 0.7

• 0.7

+ 1.7

• 2.0

+

= 3.0 µ

Boosted

1.3

• 1.4

+ 0.9

• 1.0

+

= 1.7 µ

VBF

0.8

• 0.8

+ 0.5

• 0.5

+

= 1.0 µ

had

τ

lep

τ → H

0.1

• 0.1

+ 0.3

• 0.4

+ 0.3

• 0.4

+ 0.9

• 1.0

+

= 0.9 µ

Boosted

0.6

• 0.6

+ 0.5

• 0.6

+

= 1.0 µ

VBF

0.4

• 0.5

+ 0.7

• 0.9

+

= 2.0 µ

had

τ

had

τ → H

0.1

• 0.1

+ 0.5

• 0.8

+ 0.5

• 0.5

+ 1.6

• 2.0

+

= 3.6 µ

Boosted

0.9

• 1.0

+ 0.7

• 0.9

+

= 1.4 µ

VBF

0.5

• 0.6

+

Total uncertainty

µ

• n

σ 1 ±

(statistical) σ (syst. excl. theory) σ (theory) σ

[GeV]

bb

m 50 100 150 200 250 Weighted events after subtraction / 20.0 GeV 2 4 6 8 10

Data 2012 =1.0) µ VH(bb) ( Diboson Uncertainty

ATLAS

• 1

Ldt = 20.3 fb

∫

= 8 TeV s 0+1+2 lep., 2+3 jets, 2 tags Weighted by Higgs S/B

ATLAS JHEP01 (2015) 069

H→ττ H→bb

ATLAS JHEP01 (2015) 069 ATLAS-HIGG-2013-32

SLIDE 20

Evidence for Yukawa (湯川) Interaction

20

µ

0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8

ln L Δ 2 −

2 4 6 8 10 12 14 16 18 20 σ 1 σ 2 σ 3 σ 4

σ 2.1 σ 3.2 σ 3.8

= 125 GeV

H

m b b → VH τ τ → H Combined

CMS

• 1

20 fb − = 8 TeV, L = 19 s ;

• 1

= 7 TeV, L = 5 fb s

model standard

CMS, Nature Phys. 10 (2014) 557

= 125.6 GeV

H

at m

SM

σ / σ Best fit

• 10
• 8
• 6
• 4
• 2

2 4 6 8 10

Combination Same-Sign 2l 3l 4l

h

τ

h

τ b b γ γ

CMS

• 1

= 8 TeV, 19.3-19.7 fb s ;

• 1

= 7 TeV, 5.0-5.1 fb s

ttH

CMS-HIG-13-029 CMS-HIG-14-009

SLIDE 21

• Measure with coupling

scale factors κi.

• The coupling of SM

particles to Higgs boson scales with particle mass:

• Holds up to electroweak

effects of O(5-10%).

21

top, bottom quarks top quark W boson etc. gluon gluon photon photon Higgs boson

• 4. RUN-1 Higgs coupling

Assumptions

• 1. only 1 SM-like Higgs
• 2. SM tensor structure

(spin 0, CP-even)

• 3. narrow width approx.
• 4. on-shell production and

decay (no-sense for offshell).

+ new particles

Destructive interference in both gg→H (top-bottom) and H→γγ (W-top) loops.

σ · BR (ii → H → ff) = σii·Γff

ΓH

gF = √ 2 mf

v , gV = 2 m2

V

v

(√s = 8 TeV, MH = 125 GeV)

LHC Higgs XS WG CERN Report 3 (arXiv:1307.1347)

µ = (σ · BR) (gg → H → γγ) σSM(gg → H) · BRSM(H → γγ) = κ2

g · κ2 γ

κ2

H

κ2

g(κb, κt) 1.058κ2 t 0.065κtκb + 0.007κ2 b

κ2

γ(κW , κt) |1.26κW 0.27κt|2

LO κ-framework

µ = σ · BR (σ · BR)SM

SLIDE 22

22

top, bottom quarks top quark W boson etc. gluon gluon photon photon Higgs boson

Higgs coupling strength

+ new particles

LHC Higgs XS WG CERN Report 3 (arXiv:1307.1347)

µ = (σ · BR) (gg → H → γγ) σSM(gg → H) · BRSM(H → γγ) = κ2

g · κ2 γ

κ2

H

(√s = 8 TeV, MH = 125 GeV)

κ2

g(κb, κt)

= κ2

t · σtt ggH + κ2 b · σbb ggH + κtκb · σtb ggH

σtt

ggH + σbb ggH + σtb ggH

• 1.058κ2

t + 0.007κ2 b 0.065κtκb

κ2

γ(κb, κt, κτ, κW)

=

• i,j κiκj · Γij

γγ

• i,j Γij

γγ

• |1.26κW 0.27κt|2

Destructive interference in both gg→H (top-bottom) and H→γγ (top-W) loops.

κ2

H

=

• jj=WW ∗, ZZ∗, b¯

b, τ −τ +, γγ, Zγ, gg, t¯ t, c¯ c, s¯ s, µ−µ+

κ2

jΓSM jj

ΓSM

H

• The coupling of SM particles to

Higgs boson scales with particle mass:

• Measure with coupling scale

factors κi

gF = √ 2 mf

v , gV = 2 m2

V

v

Assumptions

• 1. only 1 SM-like Higgs
• 2. SM tensor structure

(spin 0, CP-even)

• 3. narrow width approx.

σ · BR (ii → H → ff) = σii·Γff

ΓH

SLIDE 23

V

κ 0.6 0.7 0.8 0.9 1 1.1 1.2 1.3 1.4 1.5 1.6

F

κ

• 2
• 1

1 2 3 4

bb → H bb → H τ τ → H τ τ → H 4l → H 4l → H ν l ν l → H ν l ν l → H γ γ → H γ γ → H

bb → H τ τ → H 4l → H ν l ν l → H γ γ → H Combined SM Best Fit

• 1

Ldt = 20.3 fb

∫

= 8 TeV s

• 1

Ldt = 4.6-4.8 fb

∫

= 7 TeV s

ATLAS Preliminary

V

κ

0.5 1 1.5

f

κ

• 2
• 1

1 2

9 5 % C . L .

b b → H τ τ → H ZZ → H WW → H γ γ → H

CMS

(7 TeV)

• 1

(8 TeV) + 5.1 fb

• 1

19.7 fb

Observed SM Higgs

a) Higgs couplings to gauge bosons and fermions

Assume all fermion couplings scale as κF while all vector boson couplings scale as κV. Assume no BSM contributions to ΓH. Quad-fold ambiguity in sign of κF and κV. One relative sign is physical. Take κV >0 as convention and look for ± κF. κF <0 means sign of new physics. Almost degenerate minima in the likelihood: one for κF >0 and the other for κF <0. H→γγ excess prefers -κF but κF >0 for global fit. Electroweak precision data constrain κF >0. (∵ with κF <0, κV is further away from 1)

23

Data are compatible with SM predictions at 10-20% accuracy. ATLAS: κV = 1.15 ± 0.08, κF = 0.99 +0.17-0.15 at 68% C.L. CMS: κV ∈ [0.87,1.14] at 95% C.L. κF ∈ [0.63,1.15] at 95% C.L. Fermiophobic model (κF=0) is ruled out at >5σ (via ggF loop).

κV κF κF

t,b

κV

CMS-HIG-14-009 ATLAS-CONF-2014-009

SLIDE 24

Resolving the degeneracy in κF with interference in tH

ATLAS PLB 740 (2015) 222

t

κ

• 2

2 4 6 8 10 Expectation w.r.t SM

• 4

10

• 3

10

• 2

10

• 1

10 1 10

2

10

ATLAS γ γ → H , H t t = 125.4 GeV

H

m = 8 TeV, s

SM ) γ γ → H (

SM

BR ) γ γ → H BR( ) H t t (

SM

σ )/ H t t ( σ ) tH (

SM

σ )/ tH ( σ

t

κ

• 2

2 4 6 8 10 )

t

κ )( γ γ → H BR( × σ ) γ γ → H BR( × σ 95% CL limit on

• 2

10

• 1

10 1 10

2

10

3

10

limit

s

CL Observed limit

s

CL Expected σ 1 ± σ 2 ± ATLAS 2011-2012 = 7 TeV s ,

• 1

Ldt = 4.5 fb

∫

= 8 TeV s ,

• 1

Ldt = 20.3 fb

∫

t

κ

• 2

2 4 6 8 10 ln(L) Δ

• 2

0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 ATLAS 2011-2012 = 7 TeV s ,

• 1

Ldt = 4.5 fb

∫

= 8 TeV s ,

• 1

Ldt = 20.3 fb

∫

= 125.4 GeV

H

m

SLIDE 25

Higgs coupling scale factor

ATLAS-CONF-2014-009

Parameter value

• 2
• 1

1 2

ATLAS Preliminary

• 1

Ldt = 4.6-4.8 fb

∫

= 7 TeV s

• 1

Ldt = 20.3 fb

∫

= 8 TeV s

= 125.5 GeV

H

m

0.19

• 0.24

+

=0.95

Z

κ

σ 1 σ 2

τ

κ ,

b

κ ,

t

κ ,

W

κ ,

Z

κ Model: =13%

SM

p

0.14

• 0.30

+

=0.68

W

κ

σ 1 σ 2

[0.61,0.80] ∪

t

κ [-0.80,-0.50] ∈

t

κ

σ 1 σ 2

[-0.7,0.7] ∈

b

κ

σ 1 σ 2

[0.67,1.14] ∪

τ

κ [-1.15,-0.67] ∈

τ

κ

σ 1 σ 2

Total uncertainty σ 1 ± σ 2 ±

Parameter value

0.5 1 1.5 2 2.5

< 1.87

µ

κ

• 0.18

+0.19

= 0.84

τ

κ

• 0.29

+0.33

= 0.74

b

κ

• 0.15

+0.19

= 0.81

t

κ

• 0.16

+0.16

= 1.05

Z

κ

• 0.13

+0.14

= 0.95

W

κ

68% CL 95% CL

CMS

(7 TeV)

• 1

(8 TeV) + 5.1 fb

• 1

19.7 fb

68% CL 95% CL

CMS-HIG-14-009

SLIDE 26

Couplings versus Mass - Higgs-gauge boson and Yukawa -

Electroweak symmetry breaking needs to explain: Non-zero mass of W/Z gage bosons and fermions. Unitarity conservation below 1 TeV. Non-linear relation would indicate the Higgs sector is not single doublet.

26

mb(mb) = 4.16 GeV, mb(MH) = 2.76 GeV

• yF

= κF

mf v

yV = √κV mV

v

gF = √ 2mf v

gV = 2m2

V

v LHC wants to add Higgs self-couplig λ Rare decay H→µµ etc.

yF or yV

CMS-HIG-14-009

SLIDE 27

Note on Coupling versus Mass relation

Recent discussions on quark mass (M. Spira)

• 1. One can define quark mass for Yukawa coupling,
• 2. Though above are theoretically equivalent, running mass

evaluated at Higgs mass scale is better to avoid the offset due to non-universal corrections in quarks and leptons,

• 3. Use pole mass for top quark (172.5GeV).
• 4. Use PDG values for leptons and W/Z boson masses.

The universal QED corrections for leptons are small.

27

¯ gQ(MH), ¯ gQ(MQ), gpole

Q

Γ(H → Q ¯ Q) = ¯ g2

Q(MH)3MH

16π

• 1 + 17

3 αs π + O(α2

s)

• mb(mb) = 4.16 GeV, mb(MH) = 2.76 GeV
• yF

= κF

mf v

yV = √κV mV

v

gF = √ 2mf v

gV = 2m2

V

v

yF or yV

https://twiki.cern.ch/twiki/bin/view/LHCPhysics/SMInputParameter

CMS-HIG-14-009

SLIDE 28

Search for H→μμ, ee, cc, etc.

Branching ratios (Yukawa) are too small, BR(H→µµ) =8.9E-4, BR(H→µµ) =8.9E-4 for MH=125GeV. Higgs Dalitz decay BR(H→Zγ) =6.3E-3, should be searched in ffγ. Maybe accessible to charm via J/ψ+γ (BR(H→ J/ψ+γ) =2.8E-6).

28

Events/1.0 GeV

200 400 600 800 1000

Data Background model 20 × SM Higgs boson

CMS

• µ

+

µ → H (8 TeV)

• 1

19.7 fb 0,1-Jet Tight BB

[GeV]

µ µ

m

110 120 130 140 150 160

Fit

σ Data-Fit

• 3
• 2
• 1

1 2 3 /NDF = 45.7/48 = 0.953; p-value: 0.566

2

χ

CMS PAS HIG-13-007

[GeV]

• µ

+

µ

m 80 100 120 140 160 180 200 220 240 260 Events / 2 GeV

• 1

10 1 10

2

10

3

10

4

10

5

10

6

10

7

10

8

10

9

10

10

10

ATLAS

• 1

Ldt = 24.8 fb

∫

= 8 TeV s = 7 TeV s

• µ

+

µ → H

Data MC (stat)

*

γ Z/ γ WZ/ZZ/W t t WW Single Top W+jet H [125 GeV]

ATLAS PLB 738 (2014) 68

SLIDE 29

b) Custodial, weak-isospin and quark-lepton symmetries

Custodial symmetry κW=κZ ?

Measure the coupling ratio λWZ via

• 1. Ratio of BR (BRWW/BRZZ), 2. Ratio of coupling with/without H→γγ

Weak isospin symmetry κu=κd ?

2HDM (MSSM) predicts different couplings for up and down type fermions.

Quark and lepton symmetry κl=κq ?

29

λWZ = κW κZ , λdu = κd κu , λq = κ κq

Parameter value

0.5 1 1.5 2 2.5 3 3.5

• 0.46

+0.54

= 2.18

tg

λ

• 0.17

+0.19

= 0.79

Z τ

λ

• 0.14

+0.17

= 0.93

Z γ

λ

• 0.23

+0.22

= 0.59

bZ

λ

• 0.28

+0.36

= 1.39

Zg

λ

• 0.13

+0.15

= 0.87

WZ

λ

• 0.13

+0.14

= 0.98

gZ

κ

68% CL 95% CL

CMS

(7 TeV)

• 1

(8 TeV) + 5.1 fb

• 1

19.7 fb

68% CL 95% CL

Parameter value

0.5 1 1.5 2

ATLAS Preliminary

• 1

Ldt = 4.6-4.8 fb

∫

= 7 TeV s

• 1

Ldt = 20.3 fb

∫

= 8 TeV s

= 125.5 GeV

H

m

0.14

• 0.17

+

|=1.02

Z γ

λ |

σ 1 σ 2

gZ

κ ,

tg

λ ,

gZ

λ ,

Z τ

λ ,

bZ

λ ,

WZ

λ ,

Z γ

λ Model: =21%

SM

p

0.14

• 0.15

+

|=0.80

WZ

λ |

σ 1 σ 2

0.3

• 0.4

+

|=0.3

bZ

λ |

σ 1 σ 2

0.18

• 0.22

+

|=0.90

Z τ

λ |

σ 1 σ 2

0.16

• 0.22

+

|=0.73

gZ

λ |

σ 1 σ 2

0.0

• 2.2

+

|=0.0

tg

λ |

σ 1

0.16

• 0.17

+

|=1.18

gZ

κ |

σ 1 σ 2

Total uncertainty σ 1 ± σ 2 ±

CMS-HIG-14-009 ATLAS-CONF-2014-009

SLIDE 30

γ

κ

0.5 1.0 1.5

g

κ

0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8

Observed 68% CL 95% CL 99.7% CL SM Higgs

CMS

(7 TeV)

• 1

(8 TeV) + 5.1 fb

• 1

19.7 fb

γ

κ 0.8 0.9 1 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8

g

κ 0.6 0.8 1 1.2 1.4 1.6 1.8 2 2.2 2.4

SM Best fit 68% CL 95% CL ATLAS Preliminary

• 1

Ldt = 4.6-4.8 fb

∫

= 7 TeV, s

• 1

Ldt = 20.3 fb

∫

= 8 TeV, s b ,b τ τ ,ZZ*,WW*, γ γ → Combined H

c) Loop induced Higgs couplings: κgluon vs κγ 30

Data are compatible with SM predictions at 10-15% accuracy. ATLAS: κg = 1.08+0.15-0.13, κγ = 1.19+0.15-0.12 at 68% C.L. CMS: κg ∈ [0.89,1.40] at 95% C.L. κγ ∈ [0.69,1.11] at 95% C.L. No sign of BSM signal in the gg→H and H→γγ loops.

Assume tree level couplings to SM particles as in the SM (i.e. κW=κZ=κb=κτ=κt,...=1) and new particles do not contribute to the Higgs boson width.

gluon gluon photon photon Higgs t,b t, W

κg(κb, κt) κγ(κb, κt, κτ, κW )

+ new particles?

κγ κg κγ κg

ATLAS-CONF-2014-009 CMS-HIG-14-009

SLIDE 31

Higgs coupling measurements summary

Different couplings of Higgs-gauge boson and Higgs-Yukawa couplings, coupling ratios (VV, FV, du, lq), loop induced couplings, BSM BR have been tested. All are consistent with the Standard Model !

31

Parameter value

0.5 1 1.5 2 2.5

< 0.14

BSM

BR

• 0.13

+0.12

= 1.14

γ

κ

• 0.10

+0.11

= 0.89

g

κ

• 0.21

+0.23

= 1.03

lq

λ

• 0.18

+0.19

= 0.99

du

λ

• 0.13

+0.14

= 0.87

f

κ

• 0.07

+0.07

= 1.01

V

κ

• 0.12

+0.14

= 0.92

WZ

λ

68% CL 95% CL

CMS

(7 TeV)

• 1

(8 TeV) + 5.1 fb

• 1

19.7 fb

68% CL 95% CL

ATLAS-CONF-2014-009 CMS-HIG-14-009

Parameter value

• 2
• 1

1 2

ATLAS Preliminary

• 1

Ldt = 4.6-4.8 fb

∫

= 7 TeV s

• 1

Ldt = 20.3 fb

∫

= 8 TeV s

= 125.5 GeV

H

m

0.08

• 0.08

+

=1.15

V

κ

σ 1 σ 2

F

κ ,

V

κ Model: =10%

SM

p

0.15

• 0.17

+

=0.99

F

κ

σ 1 σ 2

0.12

• 0.14

+

=0.86

FV

λ

σ 1 σ 2

VV

κ ,

FV

λ Model: =10%

SM

p

0.29

• 0.14

+

=0.94

WZ

λ

σ 1 σ 2

ZZ

κ ,

FZ

λ ,

WZ

λ Model: =19%

SM

p

[0.78,1.15] ∪ [-1.24,-0.81] ∈

du

λ

σ 1 σ 2

uu

κ ,

Vu

λ ,

du

λ Model: =20%

SM

p

[0.99,1.50] ∪ [-1.48,-0.99] ∈

lq

λ

σ 1 σ 2

qq

κ ,

Vq

λ ,

lq

λ Model: =15%

SM

p

0.13

• 0.15

+

=1.08

g

κ

σ 1 σ 2

γ

κ ,

g

κ Model: =9%

SM

p

0.12

• 0.15

+

=1.19

γ

κ

σ 1 σ 2

i,u

, B

γ

κ ,

g

κ Model: =18%

SM

p 0.30

• 0.29

+

=-0.16

i.,u.

BR

σ 1 σ 2

<0.41

i.,u.

BR @ 95% CL

Total uncertainty σ 1 ± σ 2 ±

SLIDE 32

• 5. Higgs Boson Quantum Numbers

What are the quantum numbers of observed state X ?

JPC: J=spin, P=parity, C=charge conjugation

Spin0: Standard Model Higgs boson

The Standard Model Higgs boson is scalar particle (0+). CP-mixing/violation in spin-0 can exist but small in many BSM models.

Spin1: Landau-Yang theorem

Landau-Yang theorem forbids the direct decay of an on-shell spin-1 particle into a pair of massless particles. Observation of H→γγ rules out the possibility that the new resonance has spin 1, and fixes C=1 (barring C violating effects in the Higgs sector). This theorem strictly applies to an on-shell resonance (i.e. small width hypothesis).

Spin2: graviton

Theoretically difficult. Velo-Zwanziger problem with U(1) gauge field. Who will be responsible for electroweak symmetry breaking? Why haven’t we observed analogous KK excitations of SM gauge bosons?

32

LHC Higgs XS WG CERN Report 3 (arXiv:1307.1347)

But experimentalists are not biased with theory. Let’s try with H→γγ, ZZ* and WW*.

SLIDE 33

Spin/CP study in H→γγ, ZZ* and WW*

|cos θ∗| =

|sinh(∆ηγγ)|

√

1+(pγγ

T /mγγ)2

2pγ1

T pγ2 T

m2

γγ

before event selection after event selection

➭

Decay angle cosθ* in di-photon (Collins-Soper) rest frame:

33 0+

2+

m(gg)

2+

m(qq)

No event yield information (cross section) is used but shape only in these analyses.

Full final state reconstruction with 7 variables 1. invariant masses: 2. production angles: 3. decay angles:

Φ1, θ∗ Φ, θ1, θ2

mZ1, mZ2

• Ω

DJP = PSM PSM + PJP =

• 1 +

PJP

• mZ1, mZ2,

Ω|m4l

• PSM
• mZ1, mZ2,

Ω|m4l

• −1

analogy to π0→e+e-e+e-

SLIDE 34

Higgs spin/CP: combined results

Exclude pure JP=0-, 1±, 2+ (minimal coupling).(but note that LHC has not tested all models!)

34

CMS arXiv:1411:3441

)

+

/ L

P

J

ln(L ×

• 2
• 60
• 40
• 20

20 40 60 80 100 120 CMS

(7 TeV)

• 1

(8 TeV) + 5.1 fb

• 1

19.7 fb ZZ + WW → X

Observed Expected

σ 1 ±

+

σ 1 ±

P

J σ 2 ±

+

σ 2 ±

P

J σ 3 ±

+

σ 3 ±

P

J

• 1

+

1

m +

2

h2 +

2

h3 +

2

h +

2

b +

2

h6 +

2

h7 +

2

h

• 2

h9

• 2

h10

• 2

m +

2

h2 +

2

h3 +

2

h +

2

b +

2

h6 +

2

h7 +

2

h

• 2

h9

• 2

h10

• 2

q q gg production production q q

SLIDE 35

CMS study in H→ZZ*→4l final state In the SM at LO, a1=1 and a2=a3=0 Test CP-odd amplitude A3

In many BSM model, CP-odd A3~O(10-10), ex. MSSM

When a1 dominates fa3 is CP-violating fraction

Probing the tensor structure in spin 0±

35

M(H → ZZ∗ → 4l) = A1 + A3 fa3 = |A3|2 |A1|2 + |A3|2

AV V = 1

v ∗µ 1 ∗ν 2

• a1gµνm2

H + a2qµqν + a3µναβqα 1 qβ 2

• = A1 + A2 + A3

Anomalous coupling approach (current LHC analysis method)

Amplitude compatible with Lorentz and gauge invariance. Momentum dependent form-factors. Consistent only at LO.

Effective Lagrangian approach (future plan)

General effective Lagrangian compatible with Lorentz and gauge invariance. Consistent beyond LO.

Coupling of a pseudoscalar (0-) particle A to VV is loop induced that can be

• suppressed. Thus study in X→ff (Yukawa sector) will become important.

SLIDE 36

0.00 0.05 0.10 0.15 CMS Projection

Expected uncertainties on Higgs boson couplings

expected uncertainty

γ

κ

W

κ

Z

κ

g

κ

b

κ

t

κ

τ

κ

= 14 TeV Scenario 1 s at

• 1

300 fb = 14 TeV Scenario 2 s at

• 1

300 fb

ECFA HL-LHC with L=300 fb-1 (3 ab-1) physics study. Higgs mass precision ΔMH ~100 (50) MeV. Access to top-Yukawa coupling via ttH, and rare decay H→µµ. Coupling precision of 10 to 5% reachable (even few% in κγ/κZ). Detector performances (trigger, lepton-id, fake, τ/b-id) are crucial. Theory uncertainty dominates - challenge for theorists!

0.00 0.05 0.10 0.15 CMS Projection

Expected uncertainties on Higgs boson couplings

expected uncertainty

γ

κ

W

κ

Z

κ

g

κ

b

κ

t

κ

τ

κ

= 14 TeV Scenario 1 s at

• 1

3000 fb = 14 TeV Scenario 2 s at

• 1

3000 fb

• 6. High Luminosity LHC (HL-LHC)

10 100 1000 10000 1 10 100 1000

gg Σqq

WJS2012

ratios of LHC parton luminosities: 14 TeV / 8 TeV and 33 TeV / 8 TeV

luminosity ratio MX (GeV)

MSTW2008NLO

_

36

Y

κ /

X

κ )

Y

κ /

X

κ ( ∆ ~ 2

Y

Γ /

X

Γ )

Y

Γ /

X

Γ ( ∆ 0.2 0.4 0.6 0.8

H

Γ /

Z

Γ

• g

Γ

Z

Γ /

γ

Γ

Z

Γ /

W

Γ

Z

Γ /

τ

Γ

Z

Γ /

µ

Γ

µ

Γ /

τ

Γ

g

Γ /

t

Γ

g

Γ /

Z

Γ ATLAS Simulation

= 14 TeV: s

• 1

Ldt=300 fb

∫

;

• 1

Ldt=3000 fb

∫

extrapolated from 7+8 TeV

• 1

Ldt=300 fb

∫

ATLAS-PHYS-PUB-2013-007 CMS NOTE-13-002

Scenario 1 current systematic uncert. Scenario 2 theory uncert. ↘ 1/2

• ther systematics ↘ 1/√L

L = 300 fb−1 L = 3 ab−1

σ(14TeV)/σ(8TeV)

gg→H 2.6 (MX=MH) qq→qqH 2.6 (probes high MX) qq→VH 2.1 (MX=MV+MH) gg→ttH 4.7 (phase space+MX)

SLIDE 37

Higgs potential - Higgs self-coupling

One of the core physics programmes at HL-LHC, but very challenging in both experiment and theory. Is it feasible to measure Higgs self-coupling at 20-30% level at HL-LHC ? Now being discussed at ECFA HL-LHC study + LHC Higgs XS WG. 1. which channels to explore as benchmark, ex. HH→bbγγ, bbττ etc., 2. new ideas on analysis methods, ex. interference effect in kinematical variables, boosted Higgs regime, HH+jets, etc., 3. strategy for common (NLO) MC tool developments in various channels in gg→HH/ttHH, qq→qqHH/WHH/ZHH, MSSM h/H/A/H± pair production.

37

L O Q C D N N L O Q C D NLO QCD NLO QCD

qq/gg → t¯ tHH q¯ q → ZHH q¯ q′ → WHH qq′ → HHqq′ gg → HH

MH = 125 GeV

σ(pp → HH + X) [fb]

√s [TeV] 100 75 50 25 8 1000 100 10 1 0.1

• J. Baglio et al., 2013
• J. Grigao et al., 2013
• scut (GeV)

LO(pp HH) (fb)

(a) (c) (b)

10 20 30 40 200 400 600

Destructive interference between box (a) and triangle (b) diagrams. √s=14 TeV

SLIDE 38

Higgs Pair Production Cross Section

38

10-3 10-2 10-1 100 101 102 103 104 8 13 14 25 33 50 75 100 NLO[fb] s[TeV]

HH production at pp colliders at NLO in QCD

MH=125 GeV, MSTW2008 NLO pdf (68%cl)

p p

• H

H ( E F T l

• p
• i

m p r

• v

e d ) p p

• H

H j j ( V B F ) ppttHH p p

• W

H H p p

• t

j H H ppZHH

MadGraph5_aMC@NLO 10-1 100 101 102

• 4
• 3
• 2
• 1

1 2 3 4 (N)LO[fb] /SM

ppHH (EFT loop-improved) ppHHjj (VBF) ppttHH p p

• W

H H ppZHH pptjHH

HH production at 14 TeV LHC at (N)LO in QCD

MH=125 GeV, MSTW2008 (N)LO pdf (68%cl) MadGraph5_aMC@NLO

SLIDE 39

• 7. RUN-2 Higgs Analysis Strategy

Question 1: Can Higgs Analysis in Unified HEFT be possible? Question 2: How analyses should be performed in RUN-2? i) Higgs coupling, ii) off-shell coupling, iii) spin/CP, and iv) BSM Higgs searches. i) Higgs coupling

• Combine all inclusive and differential information!

ii) off-shell coupling

• Off-shell regime is not related to ΓH.
• Impossible with κ-framework. Needs to develop new HEFT

approach.

39

SLIDE 40

iii) Spin/CP

• Spin analysis
• Forget about spin-1 or 2 in RUN-2?
• Or search model which mimics the SM scalar?
• Major interest will be CP mixing/violation in 0±.
• Strategy in RUN-1 was to be Higgs production independent using Higgs

decay products only. But I think there is good physics reason to use Higgs production information in CP mixing/violation in 0±.

• NNLO+NNLL QCD correction known for CP-even. NNLO QCD only for

CP-odd but NNLL effect could be emulated by setting scale at MA/2 in analogy to SM Higgs.

• CP mixing
• Large mixing could be possible but could be difficult.
• Loop suppression of a3 in many BSM models.
• CP violation
• Possible to perform HEFT analysis with CP-violating operators.
• h/H/A→ττ, bb channels become most important in BSM.

40

SLIDE 41

LHC Schedule

• RUN-2&3
• Aiming 1f0by by end of 2015 ➭ Moriond 2016
• L=100 fb-1 by end of RUN-2, L=300 fb-1 by end of RUN-3
• L=3 ab-1 at HL-LHC
• Cross section at 13/14TeV wrt 8TeV
• ttH will get big gain due to phase space opening (→Yukawa Hbb).

41

SLIDE 42

• Approx. N3LO(+N3LL) ggF Cross Section
• Currently a lot of debates on approx.

N3LO(+N3LL) ggF XS.

• Need to wait the complete pert. N3LO by C.

Anastasiou et al. 42

baseline dFG ABNY STWZ dFMMV BBFMR BBFMR ADDFGHLM

[pb]

ggF

σ 30 35 40 45 50 55 60

NNLO F.O. NNLO NNLL NNLO NNLL NNLO F.O.

LO

3

• approx. N

F.O.

LO

3

• approx. N

F.O.

LO

3

• approx. N

LL

3

N LO

3

• part. N

F.O.

H

m = µ , /2

H

m = µ = 13 TeV, s ggF inclusive cross section, Uncertainty band: largest scale-var deviation from nominal

LO approximation uncertainty

3

Arrows: N

Run 1 HXSWG recommendation

= 13 TeV s = 125 GeV

H

m

No EW correction = 0.1171

s

α MSTW2008nnlo68cl,

SLIDE 43

[GeV]

H T,

p 20 40 60 80 100 120 140 160 180 200 [fb/GeV]

T

p / d

fid

σ d 0.01 0.02 0.03 0.04 0.05 0.06

data

• syst. unc.

H X ) + MiNLO HJ+PS ( H → gg H X ) + PS + OWHEG P ( H → gg H X ) + ES HR ( H → gg H t t + VH = VBF + H X

ATLAS

l 4 → ZZ* → H

• 1

L dt = 20.3 fb

∫

= 8 TeV s

data

• syst. unc.

H X ) + MiNLO HJ+PS ( H → gg H X ) + PS + OWHEG P ( H → gg H X ) + ES HR ( H → gg H t t + VH = VBF + H X

1) Higgs boson production cross section in categorized ggF, VBF, VH, ttH, bbH, etc. processes. 2) Higgs pT and rapidity Y.

43

top, bottom quarks gluon gluon W/Z Higgs boson

Use of Higgs Production and Decay Information

+ new particles

Use combined information of Higgs production and decay!

W/Z 3) Higgs boson decay kinematical variables (8D in H→4l)

(M4, MZ1, MZ2) , − → Ω = (θ∗, cos θ1, cos θ2, Φ1, Φ)

SLIDE 44

Differential Distributions

• Higgs pT - important probe for BSM physics !
• Future direction: analyze both yield and kin. shape !

44

[GeV]

H T,

p 20 40 60 80 100 120 140 160 180 200 [fb/GeV]

T

p / d

fid

σ d 0.01 0.02 0.03 0.04 0.05 0.06

data

• syst. unc.

H X ) +

MiNLO HJ+PS

( H → gg H X ) +

PS

+

OWHEG

P

( H → gg H X ) +

ES

HR

( H → gg H t t + VH = VBF + H X

ATLAS

l 4 → ZZ* → H

• 1

L dt = 20.3 fb

∫

= 8 TeV s

data

• syst. unc.

H X ) +

MiNLO HJ+PS

( H → gg H X ) +

PS

+

OWHEG

P

( H → gg H X ) +

ES

HR

( H → gg H t t + VH = VBF + H X

[fb/GeV]

T

p / d

fid

σ d

• 2

10

• 1

10 1

ATLAS data

• syst. unc.

H X ) +

ES

HR

( H → gg = 1.15)

ggF

K ( H t t + VH = VBF + H X

= 8 TeV s , γ γ → H

∫

• 1

dt = 20.3 fb L

[GeV]

γ γ T

p 20 40 60 80 100 120 140 160 180 200 data / prediction 2 4 6

SLIDE 45

• 7. Higgs Effective Field Theory
• Model-independent framework - HEFT
• Effective Lagrangian:

where ci is the Wilson coefficient and Λ is the cutoff scale.

• Neglecting dimension-5 operator, consider dimension-6 (di=6) basis.
• Complete basis of dimension-6 consists of 59 operators for one family.
• Assuming observed Higgs is spin-0, CP-even, part of a SU(2) doublet, narrow and no overlapping

resonances, SM local symmetry and global symmetry with L and B number conservation.

• With more than one family, number of operators depends on the flavor assumption.
• Projection of operators onto physical observables is basis-chosen dependent.
• Capable to combine EWPD, aTGC and Higgs data with common Lagrangian.
• Discussion with LHC-EW WG (VV subgroup for aTGC).
• Connection with BSM Higgs Lagrangian.
• Possible effects of heavy BSM particles encoded in higher-dimensional operators.
• Parametrization of BSM for Higgs physics: ex. 8 parameters {κg, κγ, κV, κt, κb, κτ, κZγ, κh3}.
• Assumes the scale of new physics Λ is heavy, i.e. there is no undiscovered low energy particle.
• Capable of dealing with off-shell effects.

45

Leff = L(4)

SM +

• i

1 Λdi−4 ciOi

SLIDE 46

4-fermion

• perators

2-fermion dipole

• perators

2-fermion vertex corrections Self- interactions of gauge bosons 2-fermion Yukawa interactions Higgs interactions with gauge bosons

e.g. e.g. e.g. e.g. e.g. e.g.

Dimension 6 Lagrangian

Higgs interactions with itself

e.g.

46

• A. Falkowsky,

HEFT Lecture at LAL

SLIDE 47

Brian Henning Higgs Couplings Torino 03/Oct/2014 28

Wilson coefficients ↔ observables

see upcoming paper for details

• n this mapping

(BH, X. Lu, H. Murayama)

47

Relations between Wilson coefficients and observables is dependent of the chosen basis

• f operators.
• B. Henning, HC2014,
• Oct. 1-3, 2014

SLIDE 48

48

Higgs Analysis in Unified HEFT ?

top, bottom quarks W/Z Higgs boson

+ new particles

W/Z gluon gluon

Spin/CP mix/viol. Tensor structure Higgs coupling in h(125) BSM Higgs Searches

[GeV]

A

m 200 300 400 500 600 700 800 900 1000 β tan 1 2 3 4 5 6 7 8 9 10

Preliminary ATLAS

• 1

Ldt = 4.6-4.8 fb

∫

= 7 TeV, s

• 1

Ldt = 20.3 fb

∫

= 8 TeV, s b , b τ τ , ZZ*, WW*, γ γ → Combined h

]

d

κ ,

u

κ ,

V

κ Simplified MSSM [

• Exp. 95% CL
• Obs. 95% CL

[GeV]

A

m

100 200 300 400 500 600 700 800 900 1000

β tan 10 20 30 40 50 60 70 80

=170 GeV H m =300 GeV H m =500 GeV H m =700 GeV H m = 122 GeV h m = 125 GeV h m = 128 GeV h m = 130 GeV h m = 130.2 GeV h m Obs 95% CL limit Exp 95% CL limit σ 1 σ 2 Obs 95% CL limit theory σ 1 ±

• 1

L dt = 19.5 - 20.3 fb

∫

=8 TeV, s ATLAS τ τ → h/H/A = 1 TeV,

SUSY

scenario, M

max h

MSSM m

Higgs off-shell coupling

[GeV]

4l

m 200 400 600 800 1000 [fb/GeV]

4l

/dm σ d

• 6

10

• 5

10

• 4

10

• 3

10

• 2

10

• 1

10

ZZ (S) → H* → gg ZZ (B) → gg ) ZZ → (H* → gg =10)

• ff-shell

µ ) ZZ ( → (H* → gg

Simulation Preliminary

ATLAS

µ 2 e 2 → ZZ → gg = 8 TeV s

Signal strength

• 1

1 2 3 4 5 6

ATLAS = 7 TeV s ,

• 1

Ldt = 4.5 fb

∫

= 8 TeV s ,

• 1

Ldt = 20.3 fb

∫

= 125.4 GeV

H

m , γ γ → H Combined H t t categories VH categories VBF categories ggF categories

Higgs coupling interpretation

⊗ = 0 or ∞?

SLIDE 49

iv) BSM Higgs searches

• Direct BSM Higgs searches
• Often with narrow width approximation (generally Γ<ΓSM).
• Frequently-Asked-Question: interference with continuum?
• Let’s worry after the discovery!?
• Interference depends on coupling, thus model which is assumed.
• Generally neglected as width in BSM models are smaller than that in

SM in most cases.

• However may need to take into account when non-negligible,
• ex. H→hh with large mA where ΓH blows up.
• Interpretation by simultaneous fit to 125GeV signal and BSM

Higgs searches in high-mass?

• The h-coupling fits have been used to constrain the parameter space
• f H in simple 2HDM toy-models, for example.
• 1. Assume h(125) in MSSM/2HDM.
• 2. Or assume H(125) and search light Higgs in NMSSM.

49

SLIDE 50

• Assume h(125) has been observed.
• New interpretation with “1 Higgs vs 3 Higgses”.
• Hypothesis testing the MSSM (h/H/A+BKG) hypothesis against the SM

(h+BKG) hypothesis.

[GeV]

A

m

200 400 600 800 1000

β tan 10 20 30 40 50 60

scenario

mod+ h

MSSM m

(MSSM,SM)<0.05:

S

CL Observed Expected Expected σ 1 ± Expected σ 2 ± 3 GeV ± 125

≠

h,H MSSM

m (7 TeV)

• 1

(8 TeV) + 4.9 fb

• 1

19.7 fb τ τ → h,H,A

CMS

h(125) +MSSM h/H/A→ττCombination?

50

CMS-HIG-13-021

• R. Wolf, talk at HC2014

Old method: h(125) ignored in statistical inference. New method: h(125) taken into account test statistic.

SLIDE 51

Summary

We have observed the fist elementary particle of scalar - Higgs boson.

Brout-Englert-Higgs mechanism: what an incredible purely theoretical idea !!! Experimentalists will make every endeavor for BSM physics discovery !!

LHC - hadron collider now enters in precision measurement era !

51 Higgs Property Measurements at LHC

Higgs boson mass (MH) & decay width (ΓH) MH measured at 2-3 per mille precision. No sign of BSM in ΓH, BRinv. Higgs couplings to gauge bosons (gV) and fermions (gF) Consistent with the SM prediction, gV∝mV2 , gF∝mf. Next, study in dσ/dX. Higgs boson quantum numbers JPC and tensor structure Evidence for scalar nature of 0+. No evidence for CP-mixture. Higgs potential - Higgs self-coupling λ Remains as an important territory to conquer in HL-LHC. Beyond the Standard Model Higgs (MSSM, 2HDM, etc.) No evidence, but keep looking for BSM Higgs(es) and exotic Higgs decays.

• →
• →
• →
• →
• →

SLIDE 52

LHC Higgs XS WG CERN Report Trilogy Handbook of LHC Higgs Cross Sections:

• 1. Inclusive Observables (CERN 2011-002, 151 pp)
• 2. Differential Distributions (CERN 2012-002, 275 pp)
• 3. Higgs Properties (CERN 2013-004, 392 pp)

LHC Higgs Cross Section Working Group

52

[GeV]

H

M

80 100 120 140 160 180 200

Higgs BR + Total Uncert [%]

• 4

10

• 3

10

• 2

10

• 1

10 1

LHC HIGGS XS WG 2013

b b

• µ

µ c c gg

• Z

WW ZZ

https://twiki.cern.ch/twiki/bin/view/LHCPhysics/CrossSections

[GeV]

H

M 80 100 200 300 400 500 1000 H+X) [pb]

• (pp
• 2

10

• 1

10 1 10 = 8 TeV s

LHC HIGGS XS WG 2014

H (NNLO+NNLL QCD + NLO EW)

• pp

qqH (NNLO QCD + NLO EW)

• pp

WH (NNLO QCD + NLO EW)

• pp

Z H ( N N L O Q C D + N L O E W )

• p

p

ttH (NLO QCD)

• pp

bbH (NNLO QCD in 5FS, NLO QCD in 4FS)

• pp

SLIDE 53

ggF HIGLU (NNLO QCD+NLO EW) iHixs (NNLO QCD+NLO EW) FeHiPro (NNLO QCD+NLO EW) HNNLO, HRes (NNLO+NNLL QCD) SusHi (NNLO QCD) RGHiggs (NNLO+NNNLL QCD) ggHiggs (approx. NNNLO QCD) VBF VV2H (NLO QCD) VBFNLO (NLO QCD) HAWK (NLO QCD+EW) VBF@NNLO (NNLO QCD) WH/ZH V2HV (NLO QCD) HAWK (NLO QCD+EW) VH@NNLO (NNLO) ttH HQQ (LO QCD) POWHEL (NLO QCD) MG5_aMC@NLO (NLO QCD) bbH bbh@NNLO (NNLO QCD) MG5_aMC@NLO (NLO QCD) HH HPAIR (NLO QCD) MG5_aMC@NLO (NLO QCD) + private codes. Jet-veto JetVHeto (NNLO+NNLL)* gluon top/bottom Higgs Higgs pT HqT/HRes (NLO+NNLL) ResBos (NLO+NNLL) MoRe-SusHi (MSSM,2HDM) PDF: MSTW/MMHT, CTEQ, NNPDF, etc. LHAPDF, HOPPET, APFEL Higgs Decay HDECAY (NLO++) Prophecy4f (NLO) W/Z W/Z NLO MC POWHEG MiNLO MadGrapn5_aMC@NLO SHERPA MEPS@NLO PYTHIA8 UNLOPS HERWIG++ Matchbox LO MC gg2VV NLO ME MCFM, MG5_aMC@NLO gluon Higgs Properties MELA/JHU, MEKD HEFT MG5_aMC@NLO (SILH,HC) eHDECAY MSSM/2HDM FeynHiggs, CPSuperH SusHi+2HDMC HIGLU+HDECAY

Compiled by R. Tanaka, Dec. 2014

* NLO+NNLL in differential

Tools for Higgs Analysis

Clickable Link

SLIDE 54

You are very welcome to join

• Higgs Hunting 2015, LAL-Orsay, July 31-Aug. 1st, 2015
• Higgs Coupling 2015, Autumn 2015, Durham, UK
• LHC Higgs Cross Section Working Group
• https://twiki.cern.ch/twiki/bin/view/LHCPhysics/LHCHXSWG
• Mailing List: lc-higgs@cern.ch

54