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
D. Duda, LHCDaysSplit2016
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
D. Duda, LHCDaysSplit2016
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
D. Duda, LHCDaysSplit2016
H → γγhttp://cds.cern.ch/record/2206210
ATLAS-CONF-2016-067
5 / 26
H → γγ measurements
D. Duda, LHCDaysSplit2016
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
D. Duda, LHCDaysSplit2016
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
D. Duda, LHCDaysSplit2016
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
D. Duda, LHCDaysSplit2016
H → ZZ∗
http://cds.cern.ch/record/2206253
ATLAS-CONF-2016-079
9 / 26
Xsec & properties measurements in H → ZZ ∗ → 4` events
D. Duda, LHCDaysSplit2016
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
Xsec & properties measurements in H → ZZ ∗ → 4` events
D. Duda, LHCDaysSplit2016
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
D. Duda, LHCDaysSplit2016
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
D. Duda, LHCDaysSplit2016
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
D. Duda, LHCDaysSplit2016
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
D. Duda, LHCDaysSplit2016
H → bb̄
http://cds.cern.ch/record/2206813
ATLAS-CONF-2016-091
http://cds.cern.ch/record/2206201
ATLAS-CONF-2016-063
15 / 26
VH → Vbb̄
D. Duda, LHCDaysSplit2016
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
D. Duda, LHCDaysSplit2016
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
D. Duda, LHCDaysSplit2016
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
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
D. Duda, LHCDaysSplit2016
H → µµhttp://cds.cern.ch/record/2206079
ATLAS-CONF-2016-041
19 / 26
Search for Higgs bosons decaying into di-muons
D. Duda, LHCDaysSplit2016
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
910 PreliminaryATLAS
-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
910 PreliminaryATLAS
-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
D. Duda, LHCDaysSplit2016
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
D. Duda, LHCDaysSplit2016
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
D. Duda, LHCDaysSplit2016
Back-up
23 / 26
Xsec & properties measurements in H → ZZ ∗ → 4` events
D. Duda, LHCDaysSplit2016
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
D. Duda, LHCDaysSplit2016
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
D. Duda, LHCDaysSplit2016
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