A Light Composite Higgs and its Heavy Vector Partners
Transcript of A Light Composite Higgs and its Heavy Vector Partners
A Light Composite Higgs and its Heavy Vector Partners
Kenneth Lane, with Lukas Pritchett Boston University
A Light Composite Higgs and its Heavy Vector Partners
Kenneth Lane, with Lukas Pritchett Boston University
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•
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The data
The light composite Higgs model
Tests for Run 2
⇢H , aH ! V V, V H cross sections
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⇢H , aH ! V V, V H decays
1.5 2 2.5 3 3.5
Even
ts /
100
GeV
1−10
1
10
210
310
410DataBackground model1.5 TeV EGM W', c = 12.0 TeV EGM W', c = 12.5 TeV EGM W', c = 1Significance (stat)Significance (stat + syst)
ATLAS-1 = 8 TeV, 20.3 fbs
WZ Selection
[TeV]jjm1.5 2 2.5 3 3.5
Sign
ifica
nce
2−1−0123
Run 1
ATLAS “WZ” nonleptonic
[TeV]W' m1.4 1.6 1.8 2 2.2 2.4 2.6 2.8 3
WZ)
[fb]
→ B
R(W
' ×
W')
→(p
p σ
1−10
1
10
210
310
410 Observed 95% CL
Expected 95% CL
uncertaintyσ 1±
unceirtaintyσ 2±
EGM W', c = 1
ATLAS-1 = 8 TeV, 20.3 fbs
Run 1
ATLAS “WZ” nonleptonic
[GeV]GM1000 1500 2000 2500
ZZ)
[pb]
→ bu
lk B
R(G
× 95
%σ
-310
-210
-110
1
600
observedS
Frequentist CL
σ 1± expected S
Frequentist CL
σ 2± expected S
Frequentist CL
= 0.5PlM/k ZZ), → bulk
x BR(GTHσ
= 0.2PlM/k ZZ), → bulk
x BR(GTHσ
CMS = 8 TeVs at -1L = 19.7 fb
Run 1
CMS “ZZ” semileptonic
[GeV]GM1000 1500 2000 2500
) [pb
]bu
lk G
→ (p
p 95
%σ
-310
-210
-110
1 observedS
Frequentist CL
σ 1± expected S
Frequentist CL
σ 2± expected S
Frequentist CL
= 0.5PlM/k), bulk G→ (pp THσ
I II III
CMS = 8 TeVs at -1L = 19.7 fb
600
Run 1
CMS “WW” semileptonic
(GeV)W'M1000 1500 2000
WH
) (pb
)→
*BR
(W'
95%
σ
-310
-210
-110
1
10
800
ObservedSFull CLσ 1± Expected SFull CLσ 2± Expected SFull CL
WH)→ * BR(W' W'
HVT B(gv=3):xsec WH)→ * BR(W' W'LH model:xsec
(8 TeV)-119.7 fbCMS combinedµPreliminary e+
Run 1
CMS “WH” semileptonic
Mass[TeV]1.2 1.4 1.6 1.8 2 2.2 2.4 2.6 2.8 3
Sigm
a
2−
1−
0
1
2
3
4
5ATLAS Dijet
ATLAS All-Hadronic WZ
ATLAS Dilepton plus Jet(s)
ATLAS Lepton plus Jet(s) WZ
CMS Dijet
CMS All-Hadronic WZ
CMS Dilepton plus Jet(s)
CMS Lepton plus Jet(s)
CMS WR
“WZ” resonance significances
Run 1
Mass[TeV]1.2 1.4 1.6 1.8 2 2.2 2.4 2.6 2.8 3
Sigm
a
2−
1−
0
1
2
3
4
5 ATLAS DijetATLAS DileptonATLAS All-Hadronic WWATLAS All-Hadronic ZZATLAS Dilepton plus Jet(s)ATLAS Lepton plus Jet(s) WWCMS DijetCMS DileptonCMS All-Hadronic WWCMS All-Hadronic ZZCMS Dilepton plus Jet(s)CMS Lepton plus Jet(s)
“WW,ZZ” resonance significances
Run 1
Mass[TeV]1.2 1.4 1.6 1.8 2 2.2 2.4 2.6 2.8 3
Sigm
a
2−
1−
0
1
2
3
4
5ATLAS Dilepton bb
ATLAS Lepton, MET bb
CMS Ditau Jet(s)
CMS All-Hadronic WH
CMS All-Hadronic ZH
CMS Lepton, MET bb
WH resonance significances
Run 1
• ALL models for H(125) are finely-tuned:
-> The SM (of course) -> SUSY -> even composite Higgs models! They require top, W-partners — none have been found. (see, e.g., Guidice 1307.7879 Bellazzini, Csaki, Serra 1401.2457, Barnard, et al. 1409.7391)
A new composite Higgs model
models for H(125) are finely-tuned:
-> The SM (of course) -> SUSY -> even composite Higgs models! They require top, W-partners — none have been found. (see, e.g., Guidice 1307.7879 Bellazzini, Csaki, Serra 1401.2457, Barnard, et al. 1409.7391)
Do we need top, W partners?
ALL•
A new composite Higgs model
TC models (Yamawaki, et al., Sannino, et al.)
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No plausible explanation why H(125) is so light (dilaton??)
No plausible explanation why H(125) is so much lighter than other technihadrons — where is ⇢T ??
A new composite Higgs model
(KL, PRD 90, (2014) 9, 09525; arXiv:1407:2270; KL + Luke Pritchett, in preparation; see also Chivukula, Cohen, KL NPB 343 (1990) 554)
(inspired by BHL PRD41, 1647 (1989))
A new composite Higgs model
A fine-tuned solution
NJL applied to strong ETC:
Strong ETC, not TC, drives EWSB!•
(KL, PRD 90, (2014) 9, 09525; arXiv:1407:2270; see also Chivukula, Cohen, KL NPB 343 (1990) 554)
(BHL PRD41, 1647 (1989))
A new composite Higgs model
A fine-tuned solution
NJL applied to strong ETC:
Strong ETC, not TC, drives EWSB!•
• ETC coupling is fine-tuned to be near the critical value for EWSB.
(KL, PRD 90, (2014) 9, 09525; arXiv:1407:2270; see also Chivukula, Cohen, KL NPB 343 (1990) 554)
A new composite Higgs model
A fine-tuned solution
NJL applied to strong ETC:
Strong ETC, not TC, drives EWSB!
The fine tuning: in the large-N approximation,
(BHL PRD41, 1647 (1989))
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ETC coupling is fine-tuned to be near the critical value for EWSB.
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(a physical cut-off)mf ,MH ' 2mf ⌧ ⇤ETC = ⇤
A new composite Higgs model
• WEAK TC binds T-fermions to make technihadrons with
M⇢H ,MaH , · · · = O(⇤TC) = 1 � 2TeV � MH , but ⌧ ⇤
⇢H , aH , . . .
A new composite Higgs model
• WEAK TC binds T-fermions to make technihadrons with
M⇢H ,MaH , · · · = O(⇤TC) = 1 � 2TeV � MH , but ⌧ ⇤
⇢H , aH , . . .
(this slide is too small to hold the argument)
A new composite Higgs model
• WEAK TC binds T-fermions to make technihadrons with
M⇢H ,MaH , · · · = O(⇤TC) = 1 � 2TeV � MH , but ⌧ ⇤
⇢H , aH , . . .
The Higgs is much lighter than • ⇢H , aH , . . .
A new composite Higgs model
• WEAK TC binds T-fermions to make technihadrons with
M⇢H ,MaH , · · · = O(⇤TC) = 1 � 2TeV � MH , but ⌧ ⇤
⇢H , aH , . . .
The Higgs is much lighter than • ⇢H , aH , . . .
and there are no top, W-partners!•
a simplest TC-ETC model:
LETC = G1 qiaL tRa tbR qLib + G3 T
i↵L UR↵ U�
R TLi�
+G2
�qiaL tRa U↵
R TLi↵ + h.c.�
consider this model in the limit of large-N and weak-TC
qL = (t, b)L 2 (2, 16, 3C , 1TC), tR 2 (1, 2
3, 3C , 1TC), bR 2 (1,�1
3, 3C , 1TC)
TL = (U,D)L 2 (2, 0, 1C , dTC), UR 2 (1, 12, 1C , dTC), DR 2 (1,�1
2, 1C , dTC)
In the limit of large N and weak TC:
A magic relation that makes everything else work— including disappearance of -divergence!
mt =G1NCmt
8⇡2
⇣⇤2 � m2
t ln⇤2
m2t
⌘
+G2dTCmU
8⇡2
⇣⇤2 � m2
U ln ⇤2
m2U
⌘
mU = G2NCmt
8⇡2
⇣⇤2 � m2
t ln⇤2
m2t
⌘
+G3dTCmU
8⇡2
⇣⇤2 � m2
U ln ⇤2
m2U
⌘
⇤2
Independence of NC and dTC = dim(dTC)
) G2 = (mU/mt)G1 = (mt/mU)G3
This has a pole at
##2mU2mt
mt(⇤) = 118GeV,mU(⇤) = 126GeVat ⇤ = 500TeVNC = 3, NTC = 15) MH = 250GeV
p = MH(⇤) = 250GeV
MH⇠= 2
sNCm4
t + dTCM4U
NCm2t + dTCM2
U
�tt!tt0+ (p) = m
2t
m
2tNC(p2 � 4m2
t )
8⇡2
Z 1
0dx ln
✓⇤2
m
2t � p
2x(1 � x)
◆
+m
2UNTC(p2 � 4m2
U)
8⇡2
Z 1
0dx ln
✓⇤2
m
2U � p
2x(1 � x)
◆��1
This has a pole at
##2mU2mt
mt(⇤) = 118GeV,mU(⇤) = 126GeVat ⇤ = 500TeVNC = 3, NTC = 15) MH = 250GeV
p = MH(⇤) = 250GeV
MH⇠= 2
sNCm4
t + dTCM4U
NCm2t + dTCM2
U
�tt!tt0+ (p) = m
2t
m
2tNC(p2 � 4m2
t )
8⇡2
Z 1
0dx ln
✓⇤2
m
2t � p
2x(1 � x)
◆
+m
2UNTC(p2 � 4m2
U)
8⇡2
Z 1
0dx ln
✓⇤2
m
2U � p
2x(1 � x)
◆��1
N.B.: These are masses at !scale — to be renormalized to
⇤⇤EW
⇢H and aHThe Higgs’ heavy vector partners —
• ⇢H and aH are the most accessible technihadron partners of H(125)
Describe them via Hidden Local Symmetry as the gauge bosons of an flavor symmetry.SU(2)L ⌦ SU(2)R
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KL & Luke Pritchett, PLB 753, 211-214; 1507.07102
⇢H and aH
! gL = gR ⌘ g⇢H = 3 � 5
! ⇢0H ! W+
L W�L , ⇢±
H ! W±L ZL
! a0H ! ZLH, a±
H ! W±L H
TC interactions are vectorial, isospin and parity-invariant: ⇢H and aH(minimizes S from too!)
The Higgs’ heavy vector partners —
• ⇢H and aH are the most accessible technihadron partners of H(125)
• Describe them via Hidden Local Symmetry as the gauge bosons of an flavor symmetry.SU(2)L ⌦ SU(2)R
KL & Luke Pritchett, PLB 753, 211-214; 1507.07102
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(the Goldstone bosons of EWSB)
) M⇢H⇠= MaH
Decay rates and Cross sections
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�(⇢0H ! W+W�) ⇠= �(⇢±H ! W±Z) ⇠=g2⇢H
M⇢H
48⇡
�(a0 ! ZH) ⇠= �(a± ! W±H) ⇠=g2⇢H
MaH
48⇡
�(a0H ! W+W�) ⇠= �(a±H ! W±Z) ⇠=g2⇢H
M2WM3
aH
24⇡M4⇢H
H,W±L , ZL
⇢H and aH are parity-doubled isotriplets
Near the EW phase transition are a degenerate (2,2) quartet => equal decay rates!
M⇢H(MaH
= 1.05M⇢H) �(⇢H ! V V ) (GeV) �(aH ! V H) (GeV) �(aH ! V V ) (GeV)
1800 178 184 0.82
1900 188 196 0.78
2000 198 208 0.74
for g⇢H= 3.86
M⇢H(MaH
= 1.05M⇢H) �(⇢H ! V V ) (GeV) �(aH ! V H) (GeV) �(aH ! V V ) (GeV)
1800 178 184 0.82
1900 188 196 0.78
2000 198 208 0.74
N.B.: These widths may be significantly depleted (⇠ 1/4?)
by the content of tt, tb H,WL, ZL
⇢H , aH ! V V, V H cross sections
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⇢H , aH are mainly produced at LHC via Drell-Yan.
⇢HLarge VV coupling of
aH
=> appreciable VBF too.
=> NO appreciable VBF. Small VV coupling of
ps (TeV) M⇢H (GeV) �(⇢±
H) (fb)(DY + V BF )
�(⇢0H) (fb)
(DY + V BF ) �(a±H) (fb) �(a0
H) (fb)
8 1800 1.53+0.36 0.74+0.18 0.71 0.37
8 1900 1.05+0.24 0.50+0.12 0.51 0.27
8 2000 0.73+0.15 0.36+0.08 0.36 0.17
13 1800 7.61+3.67 3.74+1.93 4.65 2.23
13 1900 5.74+2.62 2.81+1.37 3.16 1.69
13 2000 4.37+1.90 2.16+0.99 2.39 1.27
for g⇢H= 3.86, MaH
= 1.05M⇢H, YTL
= 0, YUR= �YDR
=
12
⇢H , aH ! V V, V H cross sections
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⇢H , aH are mainly produced at LHC via Drell-Yan.
⇢HLarge VV coupling of
aH
=> appreciable VBF too.
=> NO appreciable VBF.
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�DY (aH) ' 0.5�DY (⇢H)
�DY (13TeV) = 5� 7 �DY (8TeV)
�V BF (aH) < 0.01 �V BF (⇢H)
rising to about
12�DY (⇢H) at 13TeV
�V BF (⇢H) ' 14�DY (⇢H) at
ps = 8TeV,
proton pdf’s
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Small VV coupling of
) �(⇢±H) ' �(⇢+H) ' 2�(⇢0H) uniformly
ditto for aH) W+Z � W�Z, W+H � W�H
!!
• VV production from W±Z,W+W�⇢H only: but NO ZZ !
=> Distinguish W from Z — using leptonic decays.
Predictions & recommendations for Run 2-300 fb�1!
W±Z,W+W�⇢H only: but NO ZZ !•
•
=> Distinguish W from Z — using leptonic decays. VV production from
aH ⇢H . How to distinguish if degenerate?VH due to not
Predictions & recommendations for Run 2-300 fb�1!
W±Z,W+W�⇢H only: but NO ZZ !•
•
=> Distinguish W from Z — using leptonic decays. VV production from
aH ⇢H . How to distinguish if degenerate?VH due to not 1/3 of VV, not VH, production is VBF, with forward jets!
Predictions & recommendations for Run 2-300 fb�1!
W±Z,W+W�⇢H only: but NO ZZ !
•
=> Distinguish W from Z — using leptonic decays. VV production from
aH ⇢H . How to distinguish if degenerate?VH due to not 1/3 of VV, not VH, production is VBF, with forward jets!
Predictions & recommendations for Run 2-300 fb�1!
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Difficult to explain DY+VBF > few fb at 8 TeV. Therefore, Run 1 was an up-fluctuation — like H(125)! This was confirmed (!!) last December.
•
W±Z,W+W�⇢H only: but NO ZZ !
•
=> Distinguish W from Z — using leptonic decays. VV production from
aH ⇢H . How to distinguish if degenerate?VH due to not 1/3 of VV, not VH, production is VFB, with forward jets!
Predictions & recommendations for Run 2-300 fb�1!
•
Difficult to explain DY+VBF > few fb at 8 TeV. Therefore, Run 1 was an up-fluctuation — like H(125)! This was confirmed (!!) last December.
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• There will be NO top & W partners. Our model doesn’t need them!