sm higgs boson results with the tlasa detector · 2016. 10. 6. · dominik duda (nikhef) on behalf...

SM Higgs boson results with the ATLAS detector

Dominik Duda (NIKHEF)

on behalf of the ATLAS collaboration

1 / 26

Introduction

D. Duda, LHCDaysSplit2016

Discovery of boson in 2012 is greatest success ofthe LHC experiments so far

Subsequent measurements of the particleproperties are consistent with the SMHiggs-boson.

Higgs-boson mass measured by ATLAS and CMS:

mH = 125.09± 0.21(stat)± 0.11(syst)

Phys. Rev. Lett. 114, 191803

Spin and CP state of Higgs-boson are determined

probing angular distribustion of decay products

ATLAS data hints very strongly to a SpinCP

state of 0+

Alternative models are rejected with a CL ofmore than 99.9%

h+ = 0 PJ − = 0 PJ

gκ=qκ

+ = 2 P J

<300 GeVT

p

=0qκ

+ = 2 P J

<125 GeVT

p

=0qκ

+ = 2 P J

<300 GeVT

pgκ=2qκ

+ = 2 P J

<125 GeVT

pgκ=2qκ

+ = 2 P J

q~

-30

-20

-10

0

10

20

30

40

ATLAS l 4→ ZZ* →H -1 = 7 TeV, 4.5 fbs

-1 = 8 TeV, 20.3 fbs

νµνe → WW* →H -1 = 8 TeV, 20.3 fbs

γγ →H -1 = 7 TeV, 4.5 fbs

-1 = 8 TeV, 20.3 fbs

ObservedExpected

σ 1 ± SM +0σ 2 ± SM +0σ 3 ± SM +0

σ 1 ± PJσ 2 ± PJσ 3 ± PJ

This talk focuses mainly on the latest ATLAS results on SM Higgs-boson analysis

Further dedicated talks concerning tt̄H and BSM Higgs-boson searches:

Antonio Baroncelli: tt̄H measurements and combinations in ATLASZhiqing Zhang: Heavy Higgs searches in diboson �nal states in ATLASAnna Kaczmarska: Higgs boson BSM ATLASYee Chinn Yap: Search for high mass resonances through 2 γ channel in ATLAS

Eur. Phys. J. C75 (2015) 476

2 / 26

SM Higgs-boson production


4 leading production processes with di�erent

signature:

Sensitive to di�erent Higgs-couplings

ggF, tt̄H: fermions(t,b)VBF, VH: bosons(W,Z)

Processes with the smaller cross sections have

cleaner signature

VBF: two jets with large mjj and ∆ηjjVH: Additional lepton(s), high Emiss.

T or jetstt̄H: Additional leptons, high pT (heavy�avour) jets and high Emiss.

T

Cross sections at 13TeV increased by a factor of2.0 (or more) wrt to Run-I

[TeV] s6 7 8 9 10 11 12 13 14 15

H+

X)

[pb]

→(p

p σ

2−10

1−10

1

10

210 M(H)= 125 GeV

LH

C H

IGG

S X

S W

G 2

016

H (N3LO QCD + NLO EW)

→pp

qqH (NNLO QCD + NLO EW)

→pp

WH (NNLO QCD + NLO EW)

→pp

ZH (NNLO QCD + NLO EW)

→pp

ttH (NLO QCD + NLO EW)

→pp

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

→pp

tH (NLO QCD, t-ch + s-ch)

→pp

g

g

th

q'

q

W/Z

W/Z

h

q'

q

q

q

W/Z

h

W/Z

g

g

t

t

h

t

t

86% 7% 5% 0.8%

3 / 26

SM Higgs-boson decay modes


Decay mode Branching fraction [%]

H → bb̄ 57.5± 1.9H →WW ∗ 21.6± 0.9H → gg 8.56± 0.86H → ττ 6.30± 0.36H → cc̄ 2.90± 0.35H → ZZ∗ 2.67± 0.11H → γγ 0.228± 0.011H → Zγ 0.155± 0.014H → µµ 0.022± 0.001

[GeV]HM120 121 122 123 124 125 126 127 128 129 130

Hig

gs B

R +

Tot

al U

ncer

t

-410

-310

-210

-110

1

LH

C H

IGG

S X

S W

G 2

016

bb

ττ

µµ

cc

gg

γγ

ZZ

WW

γZ

At 125GeV many Higg-boson decays have a substantial BRBut not all of them can be isolated from the backgrounds

gg ,..

Some channels with low BR have much higher signal-to-background

ratios than e.g. the gg → H → bb̄ decay channel

e.g. H → γγ or H → ZZ∗ → 4` with a BR(1.2 · 10−4)

4 / 26


H → γγhttp://cds.cern.ch/record/2206210

ATLAS-CONF-2016-067

5 / 26

H → γγ measurements


Measurements of �ducial, di�erential and production

cross sections

Unbinned maximum likelihood �t on mγγ spectrumin the range 105GeV < mγγ < 160GeVSignal model: Double-sided Crystal Ball function(around 125.09GeV)Background model: two dimensional sidebandmethod (to estimate γγ, γj , jj contribution)

[GeV]γγm110 120 130 140 150 160

Fra

ctio

n [%

]

0

20

40

60

80

100 PreliminaryATLAS -1 = 13 TeV, 13.3 fbs

γγ-jetγ

jet-jet

Stat. Unc.Tot. Unc.

Object and event selection:

diphoton baseline VBF enhanced single leptonPhotons |η| < 1.37 or 1.52 < |η| < 2.37

pγ1T > 0.35mγγ and pγ2T > 0.25mγγ

Jets - pT > 30 GeV , |y| < 4.4 -- mjj > 400 GeV, |∆yjj | > 2.8 -- |∆φγγ,jj | > 2.6 -

Leptons - - pT > 15 GeV|η| < 2.47

Additional cuts/BDT to de�ne event categories (production cross section measurements)

leptonic and hadronic tt̄H categoriesVH categories corresponding to W → `ν, Z → ``, Z → νν, V → qq̄

VBFgluon-fusion

6 / 26

Fiducial and di�erential cross sections


Fiducial cross sections

No signi�cant deviations form SM predictions forthe three measurements

Fiducial region Measured cross section (fb) SM prediction (fb)

Baseline 43.2± 14.9 (stat.)± 4.9 (syst.) 62.8+3.4−4.4 [N3LO + XH]

VBF-enhanced 4.0± 1.4 (stat.)± 0.7 (syst.) 2.04± 0.13 [NNLOPS + XH]single lepton 1.5± 0.8 (stat.)± 0.2 (syst.) 0.56± 0.03 [NNLOPS + XH]

0 0.5 1 1.5 2 2.5 3 3.5 4

[fb]

fidσ

0

20

40

60

80 PreliminaryATLASdata, tot. unc.

-1 = 13 TeV, 13.3 fbs, γγ→Hsyst. unc.

= 125.09 GeVHm

XHN3LO +

XHN3LO+JVE +

XHSTWZ, BLPTW +

XHGoSam+Sherpa +

XHPowheg NNLOPS +

XHNNLOJET +

ttH + VH = VBF + XH

> 30 GeVT

p = 0.4, R tkanti

jetsN 0≥ 1≥ 2≥ 3≥

XH

Rat

io to

NN

LOP

S+

0

1

2 0 20 40 60 80 100 120 140 160 180 200

dσfid/dpγγ

T[fb/GeV]

0

0.5

1

1.5 PreliminaryATLAS

data, tot. unc.-1 = 13 TeV, 13.3 fbs, γγ→H

syst. unc.

= 125.09 GeVHm

XH NNLOPS + H→gg = 1.10H→ggk

ttH + VH = VBF + XH

pγγT[GeV]

0 20 40 60 80 100 120 140 160 180 200

data

/ pr

edic

tion

0

1

2

But: harder Higgs-boson pT spectrum in data w.r.t.

NNLOPS predictions

With a p-value of 2.3σ.Consistent with Run-I measurements of ATLAS

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

dσfid/d|cosθ

∗

|[fb]

0

50

100

150 PreliminaryATLAS

data, tot. unc.-1 = 13 TeV, 13.3 fbs, γγ→H

syst. unc.

= 125.09 GeVHm

XH NNLOPS + H→gg = 1.10H→ggk

ttH + VH = VBF + XH

| cos θ∗

|0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

data

/ pr

edic

tion

0

1

2

σ�d. vs. | cosΘ∗|Compatible with SMpredictions of a CP-evenscalar particle

Measurements are stillstatistically dominated

7 / 26

Total H → γγ production cross section and signal strength


In total considering 13 event categories

Total uncertainties dominated by

Statistics

Signal strength:

µ =σ × BRmeasured

σ × BRSM

[GeV]γγm

110 120 130 140 150 160

wei

ghts

- b

kg∑ 5−

0

5

10

wei

ghts

/ G

eV∑

0

20

40

60

80

100

120

140

160

180

200DataBackgroundSignal + BackgroundSignal

PreliminaryATLAS-1 = 13 TeV, 13.3 fbs

= 125.09 GeVH

, mγγ→H

S/B weighted sum ofevent categories

Observed signi�cance of the signal is 4.7σ,while 5.4σ is expected

σggH × BR(H → γγ) = 65+32−31 fb

σVBF × BR(H → γγ) = 19.2+6.8−6.1 fb

σVH × BR(H → γγ) = 1.2+6.5−5.4 fb

σt�tH × BR(H → γγ) = −0.3+1.4−1.1 fb

Signal Strength

2− 1− 0 1 2 3 4 5

Run-1µ

Run-2µ

ggHµ

VBFµ

VHµ

ttHµ

ATLAS Preliminary-1 = 13 TeV, 13.3 fbs

Total

0.26− 0.28+ = 1.17

Run-1µ

0.20− 0.22+ = 0.85

Run-2µ

0.28− 0.29+ = 0.59

ggH µ

0.71− 0.80+ = 2.24

VBF µ

1.05− 1.27+ = 0.23

VH µ

0.99− 1.26+ = -0.25

ttH µ

Measurements agree with SM predictionswithin 1 to 2σ

8 / 26


H → ZZ∗

http://cds.cern.ch/record/2206253

ATLAS-CONF-2016-079

9 / 26

Xsec & properties measurements in H → ZZ ∗ → 4` events


Decays via H → ZZ∗ → 4` provide high sensitivity formeasurements in the Higgs-sector

Measurement in 118GeV < m4` < 129GeV

m4l [118-129] GeV!

0jet! 1jet!

2 or more jets!

pT, j > 30 GeV!

Discriminant!BDT-ZZ!

mjj<120 GeV! mjj>120 GeV!

Discriminant!BDT-1j!

Discriminant!BDT-2jVBF!

Discriminant!BDT-2jVH!

!

>=1 leptons (pT, l > 8 GeV)!

Just counting !

BDT_ZZ:!•  pT4l •  η4l!•  KD =

log(MEHZZ/MEZZ)!

BDT_1jet:!•  pT,j!•  ηj!•  ΔR4lj!

BDT_2jet_VH:!•  pT,j1!•  pT,j2!•  ηj1!•  Δηjj!•  Δη4ljj!•  mjj!•  min(ΔRZj)!

BDT_2jet_VBF:!•  pT,j1!•  pT,j2!•  pT,4ljj!•  Δηjj!•  Δη4ljj!•  mjj!•  min(ΔRZj)!

Z+jets and tt̄ backgrounds estimated data-driven outside

the Higgs-peak region

Unbinned LH-�t on discriminating variableUse transfer factor to extrapolate to SR

[GeV]4l

m

80 90 100 110 120 130 140 150 160 170

Events

/2.5

GeV

0

5

10

15

20

25

30

35 Data

= 125 GeV)H

Higgs (m

ZZ*

tZ+jets, t

+V, VVV tt

Uncertainty

4l→ ZZ* →H 113 TeV, 14.8 fb

ATLAS Preliminary

[GeV]12m

50 60 70 80 90 100

Eve

nts

/4 G

eV

20

40

60

80

100

120

140

160

180

200

220

240 Data

Total

t t

Z+heavy

ATLAS Preliminary

CR0Inverted d113 TeV, 14.8 fb

10 / 26



Combined �ducial cross sections:

σ4`�d.,comb = 4.54+1.01−0.89 fb

SM expectation:

σ4`�d.,SM = 3.07+0.21−0.25 fb

Total cross section:

σtot = 81+18−16

pb

Compatible to SM expectation within 1.6σ

Cross section per production mode:

Measured:

σggH+bb̄H+tt̄H × BR(H → ZZ∗) = 1.80+0.49−0.44 pb

σVBF × BR(H → ZZ∗) = 0.37+0.28−0.21 pb

σVH × BR(H → ZZ∗) = 0+1.5 pb

Expected:

σSM,ggH+bb̄H+tt̄H × BR(H → ZZ∗) = 1.31± 0.07pb

σSM,VBF × BR(H → ZZ∗) = 0.100± 0.003pb

σSM,VH × BR(H → ZZ∗) = 0.059± 0.002pb

Final state measured σfid [fb] σfid,SM [fb]

4µ 1.28 +0.48−0.40 0.93 +0.06

−0.08

4e 0.81 +0.51−0.38 0.73 +0.05

−0.06

2µ2e 1.29 +0.58−0.46 0.67 +0.04

−0.04

2e2µ 1.10 +0.49−0.40 0.76 +0.05

−0.06

Vκ

0 0.5 1 1.5 2

Fκ

0

0.5

1

1.5

2

2.5

3ATLAS Preliminary

113 TeV, 14.8 fb

4l→ ZZ* →H

= 125.09 GeVH

m

Best fit

68% CL

95% CL

SM

κi are coupling-strengthscale factors

Results also on BSMcouplings (back-up)

11 / 26


Combination of H → γγand H → ZZ

∗ resultshttp://cds.cern.ch/record/2206272

ATLAS-CONF-2016-081

12 / 26

Combination of H → γγ and H → ZZ ∗ results


Inclusive production crosssection (full event sample)

Correct for detectore�ects and extrapolate tofull phase spaceStatistical uncertaintiesare dominantNo deviation from SM

is found

[TeV] s

7 8 9 10 11 12 13

[pb

]

H→

pp

σ

0

20

40

60

80

100 ATLAS Preliminary = 125.09 GeVH

m H→pp

σ

QCD scale uncertainty

)s

α PDF+⊕(scale Tot. uncert. γγ→H l4→*ZZ→H

comb. data syst. unc.

1 = 7 TeV, 4.5 fbs1 = 8 TeV, 20.3 fbs

*)ZZ (1), 14.8 fbγγ (1 = 13 TeV, 13.3 fbs

Decay channel Total cross section (pp→ H +X)√s =7TeV

√s =8TeV

√s =13TeV

H → γγ 35+13−12 pb 30.5+7.5

−7.4 pb 37+14−13 pb

H → ZZ∗ → 4` 33+21−16 pb 37+9

−8 pb 81+18−16 pb

Combination 34± 10 (stat.) +4−2 (syst.) pb 33.3+5.5

−5.3 (stat.) +1.7−1.3 (syst.) pb 59.0+9.7

−9.2 (stat.) +4.4−3.5 (syst.) pb

SM predictions [7] 19.2± 0.9 pb 24.5± 1.1 pb 55.5+2.4−3.4 pb

13 / 26

Combination of H → γγ and H → ZZ ∗ results


Production cross sections

Assume SM BRWith �ducial requirement |yH | < 2.5Data is categorised

Fit simultaneously in 7 regions

No sensitivity yet to VH and tt̄H

ggF shows good agreement to SMpredictions

Best fit value (pb) SM prediction (pb)

σggF 47.8 +9.8−9.4 44.5 ± 2.3

σVBF 7.9 +2.8−2.4 3.52 ± 0.07

σVHhad −2.5 +2.9−2.6 1.36 ± 0.03

σVHlep 0.32 +1.07−0.79 0.64 ± 0.02

σtop −0.11 +0.67−0.54 0.60 ± 0.06

Decay mode ggF VBF VHhad VHlep top

H → γγ (σ · B)γγggF (σ · B)γγVBF (σ · B)γγVHhad (σ · B)γγVHlep (σ · B)γγtop

H → ZZ∗ (σ · B)ZZggF (σ · B)ZZVBF fixed to SM fixed to SM fixed to SM

Parameter value norm. to SM value

5− 4− 3− 2− 1− 0 1 2 3 4 5

topσ

VHlepσ

VHhadσ

VBFσ

ggFσ

ATLAS Preliminary =125.09 GeVHm (ZZ)-1), 14.8 fbγγ (-1=13 TeV, 13.3 fbs

Observed 68% CL SM Prediction

14 / 26


H → bb̄


ATLAS-CONF-2016-091


ATLAS-CONF-2016-063

15 / 26

VH → Vbb̄


ggF and VBF produced Higgs-bosons decaying via

H → bb̄ have overwhelming large backgrounds

VH production modes are good candidates todiscover H → bb̄ decays

Targeting VH modes including Z → νν, Z → `` and

W → `ν decays

Thus �nal states with 0, 1 or 2 charge leptons

Categorise events (and using two sets of BDTs)

VH vs. all backgroundsVZ vs. other backgrounds

Selection 0-lepton 1-lepton 2-leptonTrigger Emiss

T EmissT (µ sub-channel)

Lowest unprescaled single leptonLeptons 0 loose lepton 1 tight lepton 2 loose leptons

(≥ 1 medium lepton)Lepton pair - - Same flavour

opposite-charge for µµEmiss

T > 150 GeV > 30 GeV (e sub-channel) -mll - - 71 < mll < 121 GeVST > 120 (2 jets), >150 GeV (3 jets) - -Jets Exactly 2 or 3 signal jets Exactly 2 or ≥ 3 signal jetsb-jets 2 b-tagged signal jetsLeading jet pT > 45 GeVmin∆φ(Emiss

T , jet) > 20◦ - -∆φ(Emiss

T , h) > 120◦ - -∆φ(jet1,jet2) < 140◦ - -∆φ(Emiss

T , EmissT,trk) < 90◦ - -

pVT regions [0, 150] GeV (2-lepton), [150, ∞] GeV

Channel

Categories2 b-tagged jets

pVT < 150 GeV pVT > 150 GeV2 jets 3 jets ≥ 3 jets 2 jets 3 jets ≥ 3 jets

0 lepton - - - BDT BDT -1 lepton - - - BDT BDT -2 lepton BDT - BDT BDT - BDT

Eve

nts

/ 0

.13

200

400

600

800

1000Data

=1.0)µVH(bb) (Dibosontt

Single topMultijetW+(bb,bc,cc,bl)Z+(bb,bc,cc,bl)UncertaintyPrefit background

ATLAS Preliminary

1

Ldt = 13.2 fb∫ = 13 TeV s

1 lep., 2 jets, 2 tags

150 GeV≥ V

Tp

VHBDT

1− 0.8− 0.6− 0.4− 0.2− 0 0.2 0.4 0.6 0.8 1Da

ta/P

red

.

0.81

1.2

Eve

nts

/ 0

.13

20

40

60

80

100

120Data

=1.0)µVH(bb) (Dibosontt

Single topZ+(bb,bc,cc,bl)UncertaintyPrefit background

ATLAS Preliminary

1

Ldt = 13.2 fb∫ = 13 TeV s

2 lep., 2 jets, 2 tags

150 GeV≥ V

Tp

VHBDT

1− 0.8− 0.6− 0.4− 0.2− 0 0.2 0.4 0.6 0.8 1Da

ta/P

red

.

0.5

1

1.5

16 / 26

Measured signal strength for VH → Vbb̄


BDT response is �tted simultaneously in the 8 regions

Systematic uncertainties with largest impact on �t

b-tagging and mistagging of c-jetsModelling of W+bb̄ and Z+bb̄ backgrounds

Fitted value of signal strength parameter

µ = 0.21+0.36−0.35 ± 0.36(stat.)

Thus compare observed signi�cance of 0.42σ toexpected sensitivity of 1.94σ

Validate analysis strategy by performing �t on VZBDT output, which gives:

µ = 0.91+0.32−0.27 ± 0.17(stat.)

The observed signi�cance of this result is 3.2σ,while the expected sensitivity is 3.0σ

DatasetLimit p0 Significance

Exp. Obs. Exp. Obs. Exp. Obs.

0-lepton 1.4+0.6−0.4 2.0 0.07 0.15 1.45 1.02

1-lepton 2.0+0.8−0.6 2.1 0.15 0.46 1.04 0.10

2-lepton 1.8+0.7−0.5 1.7 0.13 0.57 1.14 −0.17

Combined 1.0+0.4−0.3 1.2 0.03 0.34 1.94 0.42

=125 GeVH

for mSM

σ/σ=µBest fit

0 2 4 6 8 10

Combination

0 lepton

1 lepton

2 lepton

0.21 0.50− 0.51+ (

0.36− 0.35 − 0.36+ 0.36 + )

0.47 0.69− 0.73+ (

0.42− 0.55 − 0.44+ 0.59 + )

0.25 0.92− 0.94+ (

0.67− 0.64 − 0.67+ 0.67 + )

0.24 0.84− 0.90+ (

0.60− 0.58 − 0.63+ 0.64 + )

Tot. ( Stat. Syst. )Tot.

Stat.

ATLAS Preliminary 1L dt= 13.2 fb∫=13 TeV, s

=125 GeVH

for mSM

σ/σ=µBest fit

0 2 4 6 8 10

Combination

WH

ZH

0.21 0.50− 0.51+ (

0.36− 0.35 − 0.36+ 0.36 + )

0.33 0.92− 0.95+ (

0.67− 0.64 − 0.68+ 0.68 + )

0.15 0.64− 0.67+ (

0.44− 0.47 − 0.45+ 0.49 + )

Tot. ( Stat. Syst. )Tot.

Stat.

ATLAS Preliminary 1L dt= 13.2 fb∫=13 TeV, s

17 / 26

Search for bb̄γjj signatures


Search for SM H → bb̄ events producedvia VBF and in association with a photon.

Advantage of photon selection:

Suppression of QCD backgroundsS/B is improved by an order ofmagnitude w.r.t. bb̄jj channel

Trigger on high-pT photons

Use BDT (with 7 input quantities) to

further reduce non-resonant backgrounds

Input quantities show gooddata/mc agreement except for∆ηjj (thus apply reweighting)

Observed and expected 95% CL upperlimits on σ × BR are 4.0 and 6.02.3−1.7

times the SM expectation.

Signal stregth on Hγ production is foundto be −3.9+2.8

−2.7

q q

q q

H b

b̄

γ

W/Z

W/Z

q q

q q

W

W

H b

b̄

γ

qq

b

b̄

γ

g

g

q, g q, g

[GeV]bbm60 80 100 120 140 160 180 200 220 240

(Da

taB

kg

)/B

kg

0.3−

0.2−

0.1−

00.10.20.3

Events

/ 1

0 G

eV

0

10

20

30

40

50

60

70ATLAS Preliminary

1 = 13 TeV, 12.6 fbs

High BDT

Data x 10γVBF H(125) +

(QCD)γZ + (EWK)γZ +

NonRes BkgdUncertainty

18 / 26


H → µµhttp://cds.cern.ch/record/2206079

ATLAS-CONF-2016-041

19 / 26

Search for Higgs bosons decaying into di-muons


Sensitive channel to probe couplings to2nd-generation fermions

Classify di-muon events into disjoint phase spaces

Three p``T slicesTwo regions based on the muon |η|VBF topology

VBF topology uses boosted decision tree

Fourteen input variables51.3% (2.4%) of sig. (bkg.) pass cut on output

Obtain background shape and normalization from

�t to di-muon mass spectra

Sig.: Sum of Crystal Ball and GausianBkg: Breit-Wigner convolved with Gausian andexponential function devided by m3

``

Dominant uncertainties

StatisticsggF: 13-22% Higgs pT mismodellingVBF: 5% JES and 4% multi parton interaction

Eve

nts

/ GeV

-210

-110

1

10

210

310

410

510

610

710

810


-1 = 13 TeV, 13.2 fbs

Data*γZ/

EWK Z+jetsTop QuarksDiboson

10×ggF [125 GeV] 50×VBF [125 GeV]

[GeV]µµm60 80 100 120 140 160 180

Dat

a / M

C

0.5

1

1.5

Eve

nts

-210

-110

1

10

210

310

410

510

610

710

810


-1 = 13 TeV, 13.2 fbs

Data

*γZ/

EWK Z+jets

Top Quarks

Diboson

BDT Output-0.2 0 0.2 0.4 0.6 0.8 1

Dat

a / M

C0.5

1

1.5

20 / 26

Search for Higgs bosons decaying into di-muons


Binned maximum likelihood �t to observed

m`` distribution in range 110− 160GeV

Simultaneously in all seven categories

No evidence for H → µµ contribution found

For mH = 125.09GeV, the observed(expected) upper limit on σ × BR(H → µµ)at the 95% CL is 4.4 (5.5) times the SMprediction.

The measured signal strength is

µS = −2.3+2.7−2.7

Combination with Run I results gives anobserved (expected) upper limit that is 3.5(4.3) as well as

µS = −1.5+2.1−2.4

mll

Ent

ries

/ GeV

0

50

100

150

200

250

300

350

400µµ

TCentral high p -1 = 13 TeV, 13.2 fbs

ATLAS Preliminary

DataBackground model

20×Signal [125]

[GeV]µµm110 115 120 125 130 135 140 145 150 155 160

Pul

l

4−2−024

[GeV]Hm

115 120 125 130 135 140 145

) [p

b]µµ

→ B

R(H

× σ95

% C

L Li

mit

on

2−10

1−10

1

Observed Expected

σ1 ±σ2 ±

SM Higgs

-1 = 13 TeV, 13.2 fbs

ATLAS Preliminary

µµ→H

21 / 26

Summary and conclusions


Presented 13TeV results on the latest measurments of�ducial, di�erential and total production cross sections inHiggs-decays to

two photonstwo Z -bosons, which further decay to four charged leptonstwo bottom quarkstwo muons

Measurements are consistent with the SM predictions

But statistical uncertainties are still dominant

Exciting times ahead of us as new data arrives daily.

Also: Looking forward to publications for analyses based onH → ττ , H →WW

∗ or H → Zγ decays

Require more time to reach similar sensitivity as what wasachieved for Run-I

Also: �rst measurements based on tt̄H

For more details see talk by Antonio Baroncelli

22 / 26


Back-up

23 / 26



Yields in the exclusive event category are also

sensitive to BSM contribution to HZZ coupling

Use MadGraph5_aMC@NLO samplesUse Higgs characterisation frameworkE�ective �eld theory

Limits on the parameters κHVV and κAVV sinα arederived with a �t on the yields in each category

Additional information from kinematicobservables in the decay is not used

Agreement between κHVV = 0 (κAVV sinα = 0)and the observed value is 2.1σ (1.8σ)

Not excluded κHV V κAV V · sinαrange at 95% CL expected observed expected observed

[−6.3, 5.1] [0.9, 7.5] [−6.3, 6.5] [−9.7, 11.0]

HVVκ

8− 6− 4− 2− 0 2 4 6 8

ln(L

)∆

2

0

2

4

6

8

10

12

Observed

Expected113 TeV, 14.8 fb

ATLAS Preliminary

4l→ ZZ* →H

68% CL

95% CL

)α*sin(AVV

κ

10− 5− 0 5 10

ln(L

)∆

2

0

2

4

6

8

10

12

Observed

Expected113 TeV, 14.8 fb

ATLAS Preliminary

4l→ ZZ* →H

68% CL

95% CL

24 / 26


H → ττ , H → WW & H → ZγRun-I results only

JHEP 04 (2015) 117Phys. Rev. D 92, 012006 (2015)

ATLAS-CONF-2013-009

25 / 26

Some Run-1 results


ln(1

+S

/B)

w. E

vent

s / 1

0 G

eV

0

20

40

60

80

[GeV]ττMMCm

50 100 150 200Wei

ghte

d (D

ata-

Bkg

.)

0

10

20=1.4)µ((125) H=1.6)µ((110) H=6.2)µ((150) H

Data=1.4)µ((125) H

ττ →ZOthersFakesUncert.

ATLAS

VBF+Boostedττ →H-1, 4.5 fb = 7 TeVs

-1, 20.3 fb = 8 TeVs

[GeV]Hm120 125 130 135 140 145 150

0p-210

-110

1

10 = 7 TeVs,

-1 Ldt = 4.6 fb∫

= 8 TeVs , -1

Ldt = 20.7 fb∫0

Observed p

0Expected p

σ1

σ2

ATLAS Preliminary

H → ττ :

Excess over the SM bkg. is found with anobserved (expected) signi�cance of 4.5σ (3.4σ)

H → Zγ:

Expected and observed limits are 13.5 and18.2 times the Standard Model predictions

H →WW ∗:

ggF: Observed signal excess over bkgs of 6.1σ,while 5.8σ were expected.VBF: Evidence of signal excess over backgroundof 3.2σ.

0

200

400

600

800

50 100 150 200 250 300

0

50

100

150

0

stat ± Obssyst ± Bkg

HiggsWWMisidVVTopDY

Bkg - Obssyst ± Bkg

Higgs

(b) Background-subtracted

[GeV]Tm

Eve

nts

/ 10

GeV

µµee/+µe, 1≤jn(a)

Eve

nts

/ 10

GeV

ATLAS-1fb 20.3 TeV, =8 s

-1fb 4.5 TeV, =7 s

WW*→HH → Zγ

26 / 26

sm higgs boson results with the tlasa detector · 2016. 10. 6. · dominik duda (nikhef) on behalf...

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