TH-Institute25-July-2016
Effective-Field-TheoryApproachofthe
anomalousTripleGaugeCouplings
attheLHC
MinhoSon
KAIST
Greljo,Gonzalez-Alonso,Falkowski,Marzoca,SONinprogress
Lesson from Run1, part of Run 2
> πͺ(TeV)
: cut-off scale
extracted from data
Higgs Effective Field Theory
Widely separated two scales, or seemingly un-natural
hierarchy offers a remarkable bonus
StoletextfromthetalkbyRattazzi
β)*+, = β/0123. + π»ππππ
1
1
= β (:;<) +
β +
β +β―
Ξ ?)@ (A) ΞB?)@ (C)
Structural picture of EFT Racco,Wulzer,Zwirner 15β
Contino,Falkowski,Goertz,Grojean,Riva16β
πβ
πFGH
πβ
πβ =
π
πFGH
πβ
Interaction scale
Structural picture of EFT Racco,Wulzer,Zwirner 15β
Contino,Falkowski,Goertz,Grojean,Riva16β
πβ
πFGH
πβ
πβ =
π
πFGH
πβ
Interaction scale
: the only scale accessible to
a low-E observer
Typical interaction in EFT is
controlled by the effective coupling,
πΈ
π πΈ =
πβ
πFGH
β€
= πβ
πβ
Structural picture of EFT Racco,Wulzer,Zwirner 15β
Contino,Falkowski,Goertz,Grojean,Riva16β
πβ
π
π
π
π
πFGH
β πN
πβ
πO
π
π
πFGH
πβ =
πβ
π
Interaction scale
: the only scale accessible to
a low-E observer
π
B
πO
βΌ B
πO
Typical interaction in EFT is
controlled by the effective coupling,
πΈ
π πΈ =
πβ
πFGH
β€
= πβ
πβ
β
πN
1
=
πO
πΊQ
π
β πR
πO
ππΈ =
πΈ
πO
Structural picture of EFT Racco,Wulzer,Zwirner 15β
Contino,Falkowski,Goertz,Grojean,Riva16β
πβ
πFGH
πβ
πβ =
π
πFGH
πβ
Interaction scale
Typical interaction in EFT is
controlled by the effective coupling,
πΈ
π πΈ =
πβ
πFGH
β€
= πβ
πβ
Unitarity violation in EFT
ππ
ππ
πβ
ππ
πFGH
πβ
ππ
πFGH
πβ
πβ =
ππ
πFGH
πβ
ππ
π]^
ππ
ππ
πβB π
β
B
π β πFGH
β const. asπ β β
πBβ π
π B
= B +π
<
πFGH
πFGH
What if our collider was not strong
enoug h to produce π΄πππ ?
π[Q\ βΌ
π
πβB
E-growing
β βasπ β β
vs.
Validity of EFT
EarlynewphysicshintinEFTapproachreliesontheE-growingfeatureduetodecentπ/ π΅.
However,thisbenefitshouldcutoffatacertainenergyscale,πΈ < πFGH
Constraining HEFT via VV processes
WewillparameterizeBSMintheHiggsbasis
SeeβLHC HiggsCrossSectionWorkingGroupβnote
Data
Newinteractionsbeyond SM
β/0123 [Q\ = βlm + Ξβ
βo[Q\ = βlm
β’
β’
shiftofthecoupling strengthawayfromSMpredictions
newtensorstructuresofinteractionabsentinSM
πͺrtruvC
+ βπsr
π£B
Warsaw,SILHbasesetc with
SU(2)doublet HiggsH
BSM
πB (πΈ) βΌ
π
B
πlm
πΈB
πΜ
πBN
Constraining HEFT via VV processes
β\yz = ππ π}~β’ π}β¬ β π}~β¬ π}β’ π΄~ + 1 + πΏπ
β π΄}~ π}β’ π~β¬
β’ π β¬ β π β¬ π β’ π + 1 + πΏπ
π π β’ π β¬
+ππβ¦ πππ π 1 + πΏπΛ,Ε π}~
}
}~ }
~
Ε }~ }
~
+ππ
TreatLEPmeasurementsasinputs
πβ
πBN
β¬π΄
π}~β’ π~β’
β’} +ππβ¦ πππ π
πΕ½B
πΏπ
Ε = πΏπΛ,Ε β B πΏπ
β
πβ¦
πΕ β’ β¬
π π π
πBN }~ ~β’ β’}
πΕ = πβ
βThree variables for VV
{π Ε , πΏπΛ,Ε , πΏπ
β }
A difficulty of EFT approach:
Many parameters lead to a degeneracy
Decay vs 2-to-2 scattering process
πΏπ
πβ
βΌ
πlm
πlm
Main focus of Run 1
Parameters in HEFT
are π, π Μ -dependent
B
πΏπBβB πB (πΈ)
πβ
βΌ B βΌ
πlm
πlm
πlm
πB0
B
πFGH
B
πΈB
B
πFGH
Important item of Run 2
ππ
π π Μ ,
ππ
,
ππππ π
ππ
π π Μ Can see more microscopic
structure of BSM
Λβ,β’β
Λ
ππ
π π Μ β,β’β
Decay vs 2-to-2 scattering process
πΏπ
πβ
βΌ
πlm
πlm
B
πΏπBβB πB (πΈ)
πβ
βΌ B βΌ
πlm
πlm
πlm
πB0
B
πFGH
Main focus of Run 1
B
πΈB
B
πFGH
Important item of Run 2
ππ
Parameters in HEFT
are π, π Μ -dependent
π π Μ ,
ππ
,
ππππ π
ππ
π π Μ Λβ,β’β
Λ
Can see more microscopic
structure of BSM
Accessing to the truth-level
is non-trivial
Whatwewanttoknow
π Μ
= πNN, πNβ’
π Μ
vs.
Whatwecurrentlymeasure
πΕ‘Ε‘ ,π\Nβ’ , π\ etc
ππ
π π Μ β,β’β
Accessing to the truth-level
π Μ is non-trivial
SM WZβ lΞ½ll, 8TeV
1000
104
900
800
3
10
700
600
500
102
400
300
10
200
100
0
100
200
300
400
500
600
700
800
900
1000
mWW [GeV]
What we want to know
1
mWZ
[GeV]
T
1000
What is measured
mll [GeV]
What is measured
SM WWβ lΞ½lΞ½, 8TeV
104
900
800
103
700
600
500
102
400
300
10
200
100
0
100
200
300
400
500
600
700
800
900
1000
1
mWZ [GeV]
What we want to know
Pollution from the wrong events
:yourhypothesis
πNN < πuΕβ’
NN
Theory
ππ
ππNN
EFT works
EFT beaks down
Events beyond
EFT regime
bin1
bin2
β¦
πNN
Data
ππ
ππΕ‘Ε‘
bin1
bin2
β¦
πΕ‘Ε‘ <
FGH
πΕΎrΕΈ
πΕ‘Ε‘
Removal of the healthy events
:yourhypothesis
πNN < πuΕβ’
NN
Theory
ππ
ππNN
EFT works
EFT beaks down
Events beyond
EFT regime
bin1
bin2
β¦
πNN
Data
ππ
ππΕ‘Ε‘
bin1
bin2
β¦
πΕ‘Ε‘ <
FGH
πΕΎrΕΈ
πΕ‘Ε‘
You wrongly kill healthy events
mll [GeV]
What is measured
SM WWβ lΞ½lΞ½, 8TeV
1000
104
900
800
103
700
600
500
102
Youcuthereon πΕ‘Ε‘
400
300
10
200
100
0
100
200
300
400
500
600
700
800
900
1000
1
mWW [GeV]
You fail to remove these wrong events
πuΕβ’
NN
What controls EFT validity
u£¤¥
¢¢
¦
ππ
ππ^^
β
ππ^^
ª«¬
m§¨©
¦
ππΕΎrΕΈ
ππ
ππΕΎrΕΈ
Cutting on πππ is not justified.
What do we do?
In principle, if we can access to π^^ β‘ π Μ
(πlm +π®lm )(π^^ < πuΕβ’
^^ )
π3°ΕΈ (π^^ < πuΕβ’
^^ )
In mass situations, we do not have access to πππ β‘ π ²
We only hope to set a conservative bound
(π3°ΕΈ βπlm) β Ξπ β€ π®lm β€ (π3°ΕΈ βπlm ) + Ξπ
u¢¢³u£¤¥
π®lm ¢¢
+
u¢¢´u£¤¥
π®lm ¢¢
InspiredbyRacco,Wulzer,Zwirner 15β
ForgeneraldiscussionforValidityofEFT
Biekötter, Krämer,Liu,Riva15β
Contino,Falkowski,Goertz,Grojean,Riva16β
setting a conservative bound
(π3°ΕΈ βπlm) β Ξπ β€ π®lm β€ (π3°ΕΈ βπlm ) + Ξπ
u¢¢³u£¤¥
π®lm ¢¢
u
³u£¤¥
¢¢
¢¢
Ifπ®lm
u
´u£¤¥
¢¢
¢¢
> 0 &&π®lm
π3°ΕΈ β πlm β Ξπ β€
+
u¢¢´u£¤¥
π®lm ¢¢
> 0 &&Noexcess
u¢¢³u£¤¥
π®lm ¢¢
β€ (π3°ΕΈ βπlm) + Ξπ
InspiredbyRacco,Wulzer,Zwirner 15β
ForgeneraldiscussionforValidityofEFT
Biekötter, Krämer,Liu,Riva15β
Contino,Falkowski,Goertz,Grojean,Riva16β
setting a conservative bound
(π3°ΕΈ βπlm) β Ξπ β€ π®lm β€ (π3°ΕΈ βπlm ) + Ξπ
u¢¢³u£¤¥
π®lm ¢¢
u
³u£¤¥
¢¢
¢¢
Ifπ®lm
u
´u£¤¥
¢¢
¢¢
> 0 &&π®lm
π3°ΕΈ β πlm β Ξπ β€
+
InspiredbyRacco,Wulzer,Zwirner 15β
ForgeneraldiscussionforValidityofEFT
Biekötter, Krämer,Liu,Riva15β
Contino,Falkowski,Goertz,Grojean,Riva16β
u¢¢´u£¤¥
π®lm ¢¢
> 0 &&Noexcess
u¢¢³u£¤¥
π®lm ¢¢
β€ (π3°ΕΈ βπlm) + Ξπ
ü Intheabsenceofthe interferencebetweenSMandBSM
ü Inthepresenceofthe interference
β’
Incompletejustification
π®lm β (π βlmπ®lm + β. π. ) + π ®lm
π ®lm
πβ
βΌ
π lm
πlm
B
B
B
πΈ
>1
πuΕβ’
^^
forπΈ > πuΕβ’
^^
Ifatheoryisstronglycoupled, πβ β« πlm
β’
Suppression ofinterferencebyhidden selectionrules
π®lm β
(π βlmπ ®lm +
β. π. ) + π ®lm
B
βΌ π ®lm
B
-> This is whatβs
happening in aTGC
No excess scenario
:yourhypothesis
πNN < πuΕβ’
NN
Theory
ππ
ππNN
Valid EFT regime
What we propose
EFT beaks down
1.Assumepossible
cut-offscale
2.Removeevents
u¢¢´u£¤¥
fromπ®lm ¢¢ in
bin1
bin2
yoursimulation
β¦
πNN
Data
3.recastdata
inentireπ Ε‘Ε‘ distribution
4.Repeat1-3for
differentchoiceofcutoffscales
ππ
ππΕ‘Ε‘
bin1
bin2
β¦
πΕ‘Ε‘
u
³u£¤¥
¢¢
¢¢
π3°ΕΈ β πlm β Ξπ β€ π®lm
β€ (π3°ΕΈ βπlm) + Ξπ
Complication in Resonance scenario
:yourhypothesis
πNN <
Theory
ππ
ππNN
πuΕβ’
NN
EFT assumes
no resonance
bin1
Resonance
bin2
β¦
πNN
Data
ππ
ππΕ‘Ε‘
EFT behavior
Data includes
whole events
bin1
bin2
β¦
πΕ‘Ε‘
βUnphysical Fit
u
¢¢
π3°ΕΈ β πlm β Ξπ β€ π®lm
³u£¤¥
¢¢
β€ (π3°ΕΈ βπlm ) + Ξπ
ü
*Canbefixedifwerecoverfull π Μ = πNN
Inthiscase,wemightjustswitchto
resonancesearchthanrelyingon EFT
aTGC Amplitude
aTGC in WW
T, U channels participate in
Unitarity restoration in SM
Anomalous TripleGaugecouplings
πβ’
π’
π’
πβ’
π
π’¿
πβ¬
π’¿
πβ¬
Perfect cancellation of E-growing pieces
S-channel
π lm
¦,¦
sinπ
βΌ
2
(πGβ
β
π »B¼ πG )π B
T
+ π B πG
πB π
β
=0
2 πBN
Imperfect cancellation picks up E-growing behavior
sinπ B β
π
π ¦,¦ βΌ
π πG β π »B¼ πG πΏπ
Ε + π B πG πΏπ
β B
2
πN
π β¦/À,¦ βΌ
β1 β cosπ
2 2
π B πGβ β π »B¼ πG (πΏπΛΕ + πΏπ
Ε + π Ε ) + π B πG (πΏπ
β + π β )
π
πN
aTGC in WZ
T, U channels participate in
Unitarity restoration in SM
Anomalous TripleGaugecouplings
π’
π’
πβ’
πβ’
π’
π
π
πΜ
πβ’
π’
πΜ
πΜ
π
π
Perfect cancellation of E-growing pieces
π lm
¦,¦ βΌ sinπ
πB
S-channel
2 2π»¼
T
U
c B»¼ + (πtβ βπ »B¼ πt ) β (πGβ βπ »B¼ πG )
π
=0
πN πβ’
Imperfect cancellation picks up E-growing behavior
π ¦,¦ βΌ sinπ
πB
c»B¼ πΏπΛ,Ε
π
πN πβ’
ü Accessing to the polarizations
could give us further
discriminating power
2 2π»¼
π»¼ π B
π
π β¦/À,À/β¦ βΌ βsinπ
πΕ B
πN
2 2
πB
π
π β¦/À,¦ βΌ ±1 + cosπ
2c»B¼ πΏπΛ,Ε + π Ε
4c»¼
πβ’
π ¦,À/β¦
πB
π
βΌ β1 + cosπ
c»B¼ (πΏπΛ,Ε + πΏπ
Ε + π Ε )
4c»¼
πN
Quadratic vs Linear fit
πÍπ = 1 + π΅ π
+ πΆ π
π
Ε Ε
Ε° Ε °
lm
Linear: dim-6*SM
βΌ πͺ Ξβ¬B
Quadratic : dim-6*dim-6
βΌ πͺ Ξβ¬<
π
Ε = {π Ε ,πΏπΛ,Ε , πΏ π
β }
[ dim-8*SM βΌ πͺ(Ξβ¬<) ]
Inclusivecrosssections
VaryingoneaTGC atatime(nocross-term included)
οΏ½οΏ½ οΏ½οΏ½οΏ½
οΏ½ =οΏ½ οΏ½οΏ½οΏ½
οΏ½οΏ½ οΏ½οΏ½οΏ½
οΏ½οΏ½οΏ½οΏ½
πΕ
οΏ½οΏ½οΏ½οΏ½
οΏ½οΏ½οΏ½οΏ½
πΏπΛ,Ε
οΏ½οΏ½οΏ½οΏ½
πΏπ
β
οΏ½οΏ½οΏ½οΏ½
SolidLines: π Μ < β
οΏ½οΏ½οΏ½οΏ½
DashedLines: π Μ < 600GeV
οΏ½οΏ½οΏ½οΏ½
:Quadratictermsstaybeing
dominant foranycutvalueon π Μ-cut
οΏ½οΏ½οΏ½οΏ½
οΏ½οΏ½οΏ½οΏ½
οΏ½οΏ½οΏ½οΏ½
οΏ½οΏ½οΏ½οΏ½
-οΏ½οΏ½οΏ½
Ο /ΟοΏ½οΏ½
Ο /ΟοΏ½οΏ½
οΏ½οΏ½οΏ½οΏ½
οΏ½οΏ½οΏ½οΏ½
οΏ½ =οΏ½ οΏ½οΏ½οΏ½
οΏ½οΏ½οΏ½οΏ½
οΏ½οΏ½οΏ½οΏ½
-οΏ½οΏ½οΏ½
οΏ½οΏ½οΏ½
οΏ½οΏ½οΏ½
οΏ½οΏ½οΏ½
-οΏ½οΏ½οΏ½
-οΏ½οΏ½οΏ½
{λ�� δ����� δκγ }
οΏ½οΏ½οΏ½
οΏ½οΏ½οΏ½
{λ�� δ����� δκγ }
Interference terms appear to be suppressed
Deeper insight comes from Helicity Amplitude
Structural difference between WW and WZ
οΏ½οΏ½οΏ½
Helicity Amplitude
Deeper insight into the suppressed interference
Azatov,Contino,Machado, Riva16β
Cheung, Shen15β
Inthemasslesslimit
I. Gluing amplitudes to get n-pt amplitude
±
β
β π΄2 = β π΄u + β(π΄uÙ )
π΄uØ
π΄u
II. 3-pt amplitude
LittleGroupscalinguniquely fixesthe3-pointamplitudes
2
1
π
3
E.g.
π΄β 10Ï 20Ð 30Ò = π Ó
Littlegroup+NDA
ππ
πͺβN = tr(π β)
12 0Òβ¬0Ï β¬0Ð 13 0Ðβ¬0Ï β¬0Ò 23 0Ïβ¬0Ð β¬0Ò forββr < 0
[12]0Ïβ’0Ð β¬0Ò [13]0Ïβ’0Ò β¬0Ð [23]0Ðβ’0Ò β¬0Ï forββr > 0
β ββr β‘ β = 1 β [π]
β(π΄lm
β ) =1β π = 1
β(π΄®lm
) = 1 β πβN = 3
β
III. Some of SM 4-pt amplitude with |β π΄lm
| = 2 vanish
<
π΄< πβ’ πβ’ πβ’ πβ¬ = π΄< πβ’ πβ’ π β’ π β¬ = π΄< πβ’ πβ’ ππ = π΄< πβ’ π β’ πβ¬ π = 0
Azatov,Contino,Machado, Riva16β
Illustrative example
Helicity selection rule: total helicity should match
π±
πβ
π±
+
β +
β
β
π΄lm
<
=0
πβ
+
β +
+
Azatov,Contino,Machado,Riva16β
β π΄®lm
=2
<
BSM amplitude
with insertion of πͺβN βΌ tr(π β )
SM amplitude
How to interfere? Flip the helicity via VEV insertion (finite mass effect)
+
π±
πβ
β +
0
VEV
0
VEV
β
π΄lm
C
=2
πN
β
πΈ
B
+
Azatov,Contino,Machado,Riva16β
EFT interpretation of LHC data
Available analyses
Butteretal.16β
EFT interpretation of LHC data
Available analyses
Butteretal.16β
CMS-SMP-14-016
Events / (75 GeV)
Recasting WW-lvlv
CMS analysis at 8TeV
CMS
19.4 fb-1 (8 TeV)
Preliminary
4
Data
WW
WZ/ZZ/VVV
10
Top
DY
W+jets
cW/Ξ2 = 20 TeV-2
3
cWWW/Ξ2 = 20 TeV-2
10
cB/Ξ2 = 55 TeV-2
102
10
100
200
300
400
500
600
mll (GeV)
ü WeakcorrelationamongaTGC
ü π^^ < β isroughlysimilartoπ^^ < πͺ(TeV).Weakening ispronounced forπ^^ < πͺ(sub-TeV)
CMS-SMP-14-016
Events / (75 GeV)
Recasting WW-lvlv
CMS analysis at 8TeV
CMS
19.4 fb-1 (8 TeV)
Preliminary
4
Data
WW
WZ/ZZ/VVV
10
Top
DY
W+jets
cW/Ξ2 = 20 TeV-2
3
cWWW/Ξ2 = 20 TeV-2
10
cB/Ξ2 = 55 TeV-2
102
10
100
200
300
400
500
600
mll (GeV)
ü WeakcorrelationamongaTGC
ü π^^ < β isroughlysimilartoπ^^ < πͺ(TeV).Weakening ispronounced forπ^^ < πͺ(sub-TeV)
Recasting WZ-lvll
ATLAS analysis at 8TeV
ATLASarXiv:1603.02151
ü StrongcorrelationamongaTGC
ü π^^ < β isroughlysimilartoπ^^ < πͺ(TeV).Weakening ispronounced forπ^^ < πͺ(sub-TeV)
WW
CMS-SMP-14-016
WZ
ATLAS
1603.02151
ü πΏπ
β isstronglyconstrainedbyWW,notbyWZ
βFirstβ recasting of 13TeV data on aTGC
WZ
arXiv:1606.04017
ATLAS analysis
ü Nodramaticimprovement.Moreorless similarto8TeV case.
Combine all (8TeV CMS + ATLAS and 13TeV ATLAS)
Profiled95%CLboundsontheeachaTGC
fromourcombinedfitwithdiff.mVV cut
Combine all (8TeV CMS + ATLAS and 13TeV ATLAS)
Profiled95%CLboundsontheeachaTGC
fromourcombinedfitwithdiff.mVV cut
Can be widely different
EFT vs UV model
ππ 2
β¦
Contino,Falkowski,Goertz,Grojean,Riva16β
forsimilardiscussion
triplet+singlet
π
π Ø Ε}
π
π
}
βr2H = π}Ε ππ
Øo π½oΕ} + π
Þß
π½Þ + π}¦ β ππ
o π½o
+ π
Þß π½Þ}
2
2
2
2
Integrate out Triplet and Singlet and match to
EFT coefficients
πN®
πΏπΛ,Ε =
πB + πØ B
πB β πØ B
Ø
πoΕ‘
ΛΛ
πΕ‘Ε‘
πΏπ =
=
1
πB
β
πØ B
π\ β πΏπ£
1 Ø
πΏπ£ =
π oΕ‘
2
Ø
πoΕ‘
BB
=
ΛBBΛ
π
Bo πBN
3π
β²o πBN
πBN
πBN
B
B
= 0 π\ =
π =
π = β4ππ
β²o B πR = π
β²o B
2 πB^ o
2 πB^ C
π^
π^
=
β2π
ØΕ‘ B
βπ
β²o π
ØΕ‘
ΛΛ +
πØ
oΕ‘ BB
πBN
πB^
πBN
+ Ξ = 0
πB^
1
β πΕ‘Ε‘
4
ΛBBΛ
πBN
o π
β² Ε‘
πB^
Assumed LEP
bound is perfect
π B π\ β π Ø BπΏπ£ = 0 β π
β²o π
β²Þ = β
Both triplet and singlet are
required to have dm = 0
=
βπ
Ø
πB
B
B π
o
Ø
2π
πΏπΛ,Ε =
π
βπ
Bo
πΏπ
β = π Ε = 0
B
+ πβ²B πBN
2πβ²B πB^
EFT vs UV model
ππ 2
β¦
(strongly vs weakly)
triplet+singlet
π
π Ø Ε}
π
π
βr2H = π}Ε ππ
Øo π½oΕ} + π
Þß
π½Þ
+ π}¦ β ππ
o π½o} + π
Þß π½Þ}
2
2
2
2
πΏπΛ,Ε =
βπ
Bo
π B + π Ø B πBN
π
Bo
ββ B
π^
2π Ø B πB^
πΏπΛ,Ε = β0.009
β
π
o
0.75
1.5
4.5
= = = π^
1TeV
2TeV
6TeV
Weakly
coupled
Strongly
coupled
EFT works better for
a strong coupling
SimilarexerciseforWh appeared in
Contino,Falkowski,Goertz,Grojean,Riva16β
Illustration of EFT vs Direct
ππ 2
β¦
triplet+singlet
π
π Ø Ε}
π
π
βr2H = π}Ε ππ
Øo π½oΕ} + π
Þß
π½Þ
+ π}¦ β ππ
o π½o} + π
Þß π½Þ}
2
2
2
2
πΏπΛ,Ε =
βπ
Bo
π B + π Ø B πBN
π
Bo
ββ B
π^
2π Ø B πB^
: EFT constrains
πΏπ―
βππ½
WZ-lvll @8TeV
Will become more
conservative with cuts
SimilarexerciseforWh appeared in
Contino,Falkowski,Goertz,Grojean,Riva16β
© Copyright 2026 Paperzz