Post on 01-Oct-2020
SMHiggsbosoninteractionwiththeYukawasector(tau,b)inCMS
MicheledeGruttola(CERN)onbehalfofCMScollaboration
EPS,Venice(IT)5-13July2017Wednesday, 5 July 17
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CMSH->tau,b:run1legacy
Evidencetodown-typefermions
currentmeasurementmainlyconstraintthecouplingtoup-typetopquark
- combineonlyVHbbandHττ
- drivenbyHττevidence
2
CMS-HIG-13-033Nature Phys. 10 (2014) 557-560
(GeV)Hm110 115 120 125 130 135
Loca
l p-v
alue
-610
-510
-410
-310
-210
-110
1
10
210
σ 0σ 1
σ 2
σ 3
σ 4
b b→VH (exp.) (obs.)ττ →VH (exp.) (obs.) (non-VH)ττ →H (exp.) (obs.)
Combined (exp.) (obs.)
CMS -120 fb− = 8 TeV, L = 19s; -1 = 7 TeV, L = 5 fbs
µ0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8
ln L
∆ 2
−
2
4
6
8
10
12
14
16
18
20
σ 1
σ 2
σ 3
σ 4
σ 5
σ2.1
σ3.2
σ3.8
= 125 GeVHmb b→VH
ττ →H Combined
CMS -120 fb− = 8 TeV, L = 19s; -1 = 7 TeV, L = 5 fbs
modelstandard
Probability for the background-only hypothesisto describe the data
Scan of the profile likelihood as a function of the signal strength
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CMSH->bbrun1
Thethreepublicrun1CMSHbbresultshavebeencombined
VHbb
- updatedresultstoincludeggZHprocessinsignal
ttHbbBDTanalysis
VBFbb
3
Resultssignificance2.6σ(2.7expected)best-fittedµ=1.03+-0.43
CMS-HIG-14-004 10.1103/PhysRevD.92.032088
µ0 5
ln L
∆-2
0
2
4
6
8
Observedb b→H
b b→VH b b→vbf H
b b→ttH
CMS Unpublished (7 TeV)-1 (8 TeV) + 5.1 fb-119.8 fb
68% CL
95% CL
Likelihoodscansoftheobservedbest-fitsignalstrengthμ=σ/σSMforVH,VBFandttH
Higgs boson mass [GeV]115 120 125 130 135
Sign
ifican
ce
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
b b→H ExpectedObserved
CMS Unpublished (7 TeV)-1 (8 TeV) + 5.1 fb-119.8 fb
Expected and observed significances for a SM Higgs boson as a function of MH
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Outline
HiggscouplingtofermionsinCMSH->bb
- ggFnewinrun2
H->ττ
Newresultsinrun2andfutureprospect
4
Particle mass (GeV)0.1 1 10 100
1/2
/2v)
V o
r (g
fλ
-410
-310
-210
-110
1WZ
t
bτ
µ) fitε (M,
68% CL95% CL
68% CL95% CLSM Higgs
68% CL95% CLSM Higgs
CMS (7 TeV)-1 (8 TeV) + 5.1 fb-119.7 fb
Decay/Production ggF VBF VH ttH
H->ττ ✓ ✓ ✓ ✓
H->bb ✓ ✓ ✓ ✓
Analysis Document DataH->ττ HIG-16-043 35.9e-1(Full2016Data,run2)
VH->bb HIG-13-012 legacyrun1,run2comingsoon...
VBFH->bb HIG-16-003 2.32e-1run2
ttH->bb HIG-16-038 12.9e-1run2
ggH->bb HIG-17-010 35.9e-1(Full2016Data,run2)
FocusisonmostRecentresults.H->ττhasbeenupdatedwithfull2016luminosityonlySMHresultsherenewCMSggH->bbcoveredintalkbyC.VernierittHbbcoveredinD.Salernotalk
https://arxiv.org/pdf/1610.07922.pdf
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H->ττ(HIG-16-043)
H->ττisthecleanestchannelforstudyingtheYukawacouplingslessbackgroundthanH->bb
4taudecaychannels(eτ,μτ,eμ,ττ)eachwith3eventcategories(0-jet,VBF,Boosted).
run2analysisisdoneextractingthesignalin2-dimensionsmττ+2ndchosentargetingspecificprodmodes(τdecay,di-jetmass,higgspT)
VHincludedassignal,butnottargetedbyseparatecategory.FullVHwillcomelater
5
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H->ττ:svFitMass
mττisreconstructedusingSVFit(dynamicallikelihoodtechniques)inmostcategories
AllowsforsomeseparationofZ→ττandH→ττ,andshifttheH→ττpeakto125GeV.
inputsare
Missingtransverseenergy(MET)
METuncertainty
eachtaucandidate’sfourvector.
- AssumesallMETintheeventisfromneutrinosintaudecay
6
mass distribution (GeV)ττ→H0 50 100 150 200 250
arbi
trary
uni
ts
0
0.02
0.04
0.06
0.08
0.1
0.12
0.14
0.16
0.1813 TeV
CMS SimulationPreliminary vism
ττm
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2Dbinneddistributions
7
(GeV)vism60 80 100 120
Prob
abilit
y de
nsity
0.01
0.02
0.03
0.04
0.05
0.06
0.0713 TeVCMS Simulation Preliminary
)hτµ (0jet, ττ→ggH
1 pr
ong
0 π1
pron
g +
3 pr
ongs
(GeV)ττm50 100 150 200
(GeV
)jj
m400
600
800
1000
1200
1400
1600
1800
Prob
abilit
y de
nsity
0
0.01
0.02
0.03
0.04
0.05
13 TeVCMS Simulation Preliminary
)hτµ (VBF, ττ→qqH
(GeV)ττm50 100 150 200
(GeV
)ττ Tp
0
50
100
150
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300
350
400
Prob
abilit
y de
nsity
0
0.005
0.01
0.015
0.02
0.025
0.03
0.03513 TeVCMS Simulation Preliminary
)hτµ (boosted, ττ→ggH
(GeV)vism60 80 100 120
Prob
abilit
y de
nsity
0
0.05
0.1
0.15
0.2
0.25
0.3
13 TeVCMS Simulation Preliminary
)hτµ (0jet, µµ→Z
1 pr
ong
0 π1
pron
g +
3 pr
ongs
(GeV)ττm50 100 150 200
(GeV
)jj
m
400
600
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1000
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1400
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1800
Prob
abilit
y de
nsity
0
0.02
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0.16
13 TeVCMS Simulation Preliminary
)hτµ (VBF, ττ→Z
(GeV)ττm50 100 150 200
(GeV
)ττ Tp
0
50
100
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Prob
abilit
y de
nsity
0
0.002
0.004
0.006
0.008
0.01
0.012
0.014
0.016
0.018
0.02
0.022
13 TeVCMS Simulation Preliminary
)hτµW+jets (boosted,
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Backgroundsestimation
8
(13 TeV)-1 35.9 fbhτµ
CMSPreliminary
(GeV)Tm0 20 40 60 80 100120140160180
Even
ts
0
10000
20000
30000
40000
50000
60000
70000
80000Observed
ττ→Zµµ→Z
ElectroweakQCD multijettt
(13 TeV)-1 35.9 fbhτµ
CMSPreliminary
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Unrolled2D
9
channel category
exampleforττboostedcategory
Redlineispullw.r.t.tobackground
(GeV)ττm
0-40
40-6
060
-70
70-8
080
-90
90-1
0010
0-11
011
0-12
012
0-13
013
0-15
015
0-20
020
0-25
00-
4040
-60
60-7
070
-80
80-9
090
-100
100-
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0-40
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0010
0-11
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015
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00-
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070
-80
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090
-100
100-
110
110-
120
120-
130
130-
150
150-
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250Bk
g. u
nc.
(Obs
. - b
kg.)
2−024
Even
ts/b
in
1−10
1
10
210
310
410 < 100 GeVττ
T0 < p < 170 GeVττ
T100 < p < 300 GeVττ
T170 < p > 300 GeVττ
Tp
(13 TeV)-135.9 fbCMS Preliminary , Boostedhτhτ
Observed
= 1.06)µ (ττ→H
ττ→Z
/eeµµ→Z
+jetstt
W+jets
QCD multijet
Others
Total unc.
= 1.06)µ (ττ→H
Bkg. unc.Obs. - bkg.
Bkg. unc.ττ→H
Bkg. unc.
100<ptττ<170 170<pt
ττ<300
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H->ττ:results
10
Best Fit signal strength : 1.06 ± 0.25
log(S/S+B) plot has been made from every bin from the unrolled 2-Ddistributions
Expected (postfit) significance is 4.7 σ
Observed significance is 4.9 σ
log(S/(S+B))3− 2.5− 2− 1.5− 1− 0.5− 0
Even
ts
1−10
1
10
210
310
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510
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710
ττ→Z µµee/→Z
+jetstt W+jets
QCD multijet Others
=1.06)µ (ττ→H Bkg. unc.
Observed
(13 TeV)-135.9 fb
CMSPreliminary
log(S/(S+B))1.5− 1− 0.5−
00.20.40.60.8
11.21.41.61.8
(Obs. - bkg.)/bkg.)/bkg.ττ→(H
Bkg. unc.
SMσ/σ = µBest fit
0 1 2 3
0-jet -0.82 +0.90.82
Boosted -0.37 +0.41.11
VBF -0.29 +0.311.07
Combined -0.24 +0.251.06
CMSPreliminary
(13 TeV)-135.9 fb
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H->bbH->bbhasthelargestbranchingfraction@125GeV:58%
LargeQCD-inducedbbbackgrounds(overwhelmingforggH)
VHandttH:(semi)leptonicdecaychannels
- lowercrosssection,butpureQCDbackgroundisnotdominant
VBF:2q2bfinalstate
- highercrosssection,butQCDbackgroundirreducible
- approachwithdedicatedtriggers
ggH->bbthoughttobeimpossible,
- butnewsophisticatedanalysisinCMSdisproveit,seeC.Vernieri
11 [GeV] HM100 200 300 400 500 1000
H+X
) [pb
]
�(p
p �
-210
-110
1
10= 7 TeVs
LHC
HIG
GS
XS W
G 2
010
H (NNLO+NNLL 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)
�pp
[GeV]HM80 100 120 140 160 180 200
Hig
gs B
R +
Tot
al U
ncer
t
-410
-310
-210
-110
1
LHC
HIG
GS
XS W
G 2
013
bb
oo
µµ
cc
gg
aa aZ
WW
ZZ
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VBF->bbHIG-16-003
12
HIG-16-003Ev
ents
/ 0.
02
-310
-110
10
310
510
710810 (13 TeV)-12.32 fbCMS
SingleBPreliminary
Data
VBF, m(H) = 125 GeV
GF, m(H) = 125 GeV
H, m(H) = 125 GeVtt
1.10)×QCD (
tt
W + jets
Z + jets
Single t
MC stat. unc.
BDT output-1 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1D
ata
/ MC
- 1
-1-0.5
00.5
1 fit mbb in each category
Even
ts /
5.0
GeV
68
101214161820222426
(GeV)bbm80 100 120 140 160 180 200
Dat
a - B
kg
-15-10-505
1015
CAT 4Data
= 125 GeV)H
(mBkg.QCD
bkg. unc.σ2 bkg. unc.σ1
CMS (13TeV)-12.32 fbPreliminary
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run2:H->ττhasbeenupdatedwithfull2016luminosity.
ObservationofStandardModelH->ττwith4.9sigmaexcess!!!
HbbaddingggHtootherprodmodesrun2statisticsonhandwillexceedrun1resultandlikelytocloseuponobservationAnotherproductionyearofLHChasjuststartedwithupgradedPixelandForwardHadronicdetectorsinCMS.
Conclusionsandprospects....
13
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BACKUPWednesday, 5 July 17
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H->bb:ttHbbHIG-16-038
Searchinleptons+jetsanddileptonchannelMainbackgrounds:tt+(bb/cc/lightquarks/b/t),tt+V,W/Z+jets,diboson&QCD
AnalysisstrategyLookforhighjetmultiplicityandmanybtags,ClassifyeventsinNjetandNbjetsbins
15
see more details in talk by Daniel Salerno
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ttH->bbresults
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see more details in talk by Daniel Salerno
Wednesday, 5 July 17
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yes,theHiggsbosoninteractswithmatter!
17
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ggZH
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func(Xsection*BR,eff,bkgs)
19
[GeV] HM100 200 300 400 500 1000
H+X
) [pb
]
�(p
p �
-210
-110
1
10= 7 TeVs
LHC
HIG
GS
XS W
G 2
010
H (NNLO+NNLL 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)
�pp
AssociationwithZ/W
Associationwithttbar Hàbb
overwhelmingQCD:needtogowithassociatedproduction,§VH-canuselepton/METandtopology§ttH-evenlessrate,lookattopology,butttbarbkgwellunderstood§VBFrecentlyadded
Hàττ§gluonfusiondifficultbutpossible(canuseassociationwithjetsorgotohighptregime)§VBFcleaner§VHandttHalsoaddedveryimportantforstudyHiggsproperties!
Vectorbosonfusion
g-gfusion
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[GeV]HM80 100 120 140 160 180 200
Hig
gs B
R +
Tot
al U
ncer
t
-410
-310
-210
-110
1
LHC
HIG
GS
XS W
G 2
013
bb
oo
µµ
cc
gg
aa aZ
WW
ZZ
SM#BR#theory#uncertain1es##245%#for#most#important#ones#
mH=125.09#GeV#Regionofinterest
20
b’sandtau’sßtesttheHiggscouplingstofermionsvsbosons
VitalpartoftheHiggsidentificationandHiggspropertystudies
Butlifeishard…
But σbb(QCD) ~ 107 σxBR(Hàbb)!
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VBFaddendum
21
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Other production processes • ggZH:%%
– O(10%)%effect%on%VHbb%in%SM,%higher%pT%than%qqZH%
%%
%
%
• tHq%+%tHW%– Not%really%sensiDve%but%has%larger%effects%for%negaDve%couplings%%
%
%%
• bbH%– Similar%to%IH%but%not%really%disDnguishable%from%ggF%
Sep%1,%2015% Marco%Pieri%UC%San%Diego% 11%
otherptoductionmechanisms
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VHbbstrategy
23
•5channels:–Z(ll)Hbb–Z(νν)Hbb–W(lν)Hbb
Generalstrategy:
(a)Highboostedvectorbosonanddijet,(b)2b-taggedjets,(c)back-to-backV&H(d)Reconstructmbb
First CMS VHbb 2011 analysis Phys. Lett. B 710(2012) 284-306
ZH->µµbbcandidate
Mbb =128GeVpT(bb)=181GeV
AssociatedProduc.onàfinalstateswithleptons,METandb-jets
b-jetCSV~0.99
b-jetCSV~0.92
H->bb
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• alsonew2012– Improved tau ID and new mass reconstructions (20% better mass resolution)
Mττresolution
24
2011analysisinPLB:Phys.Lett.B713(2012)68-90
– Event-by-eventestimatoroftruem(ττ)likelihoodusingmomentaofvisibledecayproducts,anglesandMETdirectionsandexpectedresolution
L= ×
H/Zseparation
[GeV]vism0 50 100 150 200 250
[1/G
eV]
vis
1/dm
0
0.02
0.04
0.06
0.08
0.1
0.12
0.14
0.16
0.18
0.2 = 125 GeVH mττ →H
ττ →Z
= 8 TeVsCMS Simulation hτµ
[GeV]ττm0 50 100 150 200 250
[1/G
eV]
ττ1/
dm
0
0.02
0.04
0.06
0.08
0.1
0.12
0.14
0.16 = 125 GeVH mττ →H
ττ →Z
= 8 TeVsCMS Simulation hτµ
visible mass
estimated mττ
METx
exp resolution
METy
exp resolution
H->ττ
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