New physics hunting with top quarks Graldine SERVANT, CERN-TH based - - PowerPoint PPT Presentation

SLIDE 1

Géraldine SERVANT, CERN-TH

• Léa Gauthier, Anne-Isabelle Etienvre (ATLAS, SPP, CEA Saclay )

in preparation (short preview in chapter 12 of 1005.1229 & in DESY-PROC-2010-01)

based on collaborations with

• Céline Degrande, Jean-Marc Gérard, Christophe Grojean & Fabio Maltoni

1010.6304, JHEP

New physics hunting with top quarks

1104.1798, PLB + 1204.xxxx

• Roberto Contino

0801.1679, JHEP

SLIDE 2

Te top quark as a link to BSM

• Weakly coupled New Physics (NP) at the TeV scale -> susy

As today, still two paradigms for electroweak symmetry breaking:

• Strongly coupled NP at the TeV scale -> composite higgs

Particularly motivated is the case in which the Higgs is the Goldstone Boson of a spontaneously broken global symmetry (a kind of pion from a new strong sector) = strong EW symmetry breaking with Partial Compositeness

L=LSM(H)+Lsrong +Lmix

SLIDE 3

Quantum numbers of the Goldstones fixed by the symmetry breaking pattern in the strong sector: G -> H

SLIDE 4

SU(2)L × SU(2)R

SU(2)V

SU(3)c

QCD: global symm.

• n u,d

strong int.

U ( 1 )Q

⊃ 6 - 3 = 3 PNGB π±, π0 global symm. on techniquarks

SO(6) × U(1)x

SO(5) × U(1)Y

SU(Nc)

Composite Higgs: ⊃ SU(2) × U(1)Y 16 - 11 = 5 PNGB H, S SO(5)/SO(4) -> SM Higgs SO(6)/SO(5) -> SM + Singlet SO(6)/SO(4) -> 2 Higgs Doublet Model associated LHC tests

Higgs scalars as pseudo-Nambu-Goldstone bosons of new dynamics above the weak scale

New strong sector endowed with a global symmetry G spontaneously broken to H → delivers a set of Nambu Goldstone bosons

SLIDE 5

G H NG NGBs rep.[H] = rep.[SU(2) × SU(2)] SO(5) SO(4) 4 4 = (2, 2) SO(6) SO(5) 5 5 = (1, 1) + (2, 2) SO(6) SO(4) × SO(2) 8 4+2 + ¯ 42 = 2 × (2, 2) SO(7) SO(6) 6 6 = 2 × (1, 1) + (2, 2) SO(7) G2 7 7 = (1, 3) + (2, 2) SO(7) SO(5) × SO(2) 10 100 = (3, 1) + (1, 3) + (2, 2) SO(7) [SO(3)]3 12 (2, 2, 3) = 3 × (2, 2) Sp(6) Sp(4) × SU(2) 8 (4, 2) = 2 × (2, 2), (2, 2) + 2 × (2, 1) SU(5) SU(4) × U(1) 8 45 + ¯ 4+5 = 2 × (2, 2) SU(5) SO(5) 14 14 = (3, 3) + (2, 2) + (1, 1)

[Mrazek et al, 1105.5403]

• > Agashe, Contino, Pomarol’05

SLIDE 6

Limits from Higgs searches on the composite Higgs for the two minimal composite higgs models

Espinosa et al, 1202.1286

= (v/f)^2, measures the amount of compositeness of the Higgs boson

(-> 0 in the SM elementary Higgs limit)

SLIDE 7

General structure -> Partial compositeness EWSB

︴ ︴ ︴

━━━━━━

W a

µ , Bµ

Ψ

φ± φ0, h

• ex: SO(5) → SO(4)

SM sector

Lint = AµJµ + ¯ ΨO + h.c.

linear couplings

strong sector

(for more successful phenomenology)

L =¯ qL ∂ qL + ¯ tR ∂ tR

• Q

− Q

• + ∆L ¯

qL (T, B) + ∆R ¯ tR ˜ T

• + Tr

¯ Q (∂ − MQ) Q

• Lelementary

Lcomposite Lmix

• + ¯

˜ T (∂ − M ˜

T) ˜

T ˜ T + Y∗ Tr{ ¯ Q H} ˜ T + h.c

2 1 G→H⊃SO(4)

custodial SO(4) ≅ SU(2)×SU(2)

to avoid large corrections to the T parameter

SLIDE 8

tR

T ˜ T ˜ T T tL

H H

Naturalness implies light top partners

m2

H ∼ 3y2 t

8π2 m2

T

SLIDE 9

After diagonalizing through a composite/elementary rotation:

cos ϕL − sin ϕL

sin ϕL

cos ϕL

( ) ( )

qL

QL

( )

qL

QL

|SM >= cos ϕ |elem > + sin ϕ |comp >

tan ϕqL = ∆L M2

the larger the mixing, the larger the mass

Yukawa hierarchy comes from the hierarchy of compositeness

Third family most sensitive to strong dynamics

Essentially only the top talks to the new strong sector

SM Yukawa given by the composite components:

yt = Y∗ sin ϕqL sin ϕtR

{tR ↔ ˜ T}

and do the same for

“Partial compositeness”

Elementary SM fermions mix with fermionic resonances of the strong sector

[Agashe, Contino & Pomarol ‘05] [Kaplan, ‘80s]

SLIDE 10

Dual description in terms of higher-dimensional theories resonances of the strong sector (heavy top partners) Kaluza-Klein excitations strong sector warped extra dimension

→ UV completion → flavor addressed

SLIDE 11

Example of strong dynamics:

Higgs profile

➫

Bulk

UV

brane

IR

brane

SM fields live here

SM sector Composite sector

UV brane Bulk + IR brane

A warped extra dimension

ds2 = e−2kydxµdxνηµν − dy2

SLIDE 12

• Heavy partners of (tL , bL) will form a (2,2)2/3

SU(2)L × SU(2)R × U(1)X

[ under ]

Composite (EW symm. break. ) sector:

(Q, Q) = (2, 2)2/3 Q =

• T

B ⇥ Q =

• T5/3

T2/3 ⇥

electric charge +5/3

➙ “custodian”

(1, 1)2/3 = ˜ T H = (2, 2)0 = ⇤ φ† φ+ φ− φ0 ⌅

Custodial invariance of the strong sector implies larger multiplets of SU(2)L × SU(2)R × U(1)X

⤷

SM sector: (tL ,bL) tR

+ Y∗ Tr{ ¯ Q H} ˜ T + h.c

[ mass mixing terms between the 2 sectors ]

Light custodial partners of the top quark

MQ = M2 = MQ cos ϕqL

custodians become very light if SM top is largely composite

MQ → 0

sin ϕqL → 1

for

as 5 = (2, 2) ⇤ (1, 1),

2 SU(2)_L doublets + 1 singlet

SLIDE 13

Lyuk =Y∗ sin ϕL sin ϕR ⇧ ¯ tLφ†

0tR − ¯

bLφ−tR ⌃ + Y∗ cos ϕL sin ϕR ⇧ ¯ Tφ†

0tR − ¯

Bφ−tR ⌃ + Y∗ sin ϕL cos ϕR ⇧ ¯ tLφ†

0 ˜

T − ¯ bLφ− ˜ T ⌃ + Y∗ sin ϕR ¯ T5/3φ+tR + ¯ T2/3φ0tR ⇥ + Y∗ cos ϕL cos ϕR ⇧ ¯ TLφ†

0 ˜

TR − ¯ BLφ− ˜ TR ⌃ + Y∗ ⇧ ¯ TRφ†

0 ˜

TL − ¯ BRφ− ˜ TL ⌃ + Y∗ cos ϕR ⇧ ¯ T5/3φ+TR + ¯ T2/3φ0 ˜ TR ⌃ + Y∗ ⇧ ¯ T5/3φ+TL + ¯ T2/3φ0 ˜ TL ⌃ + . . .

Before EW symmetry breaking:

M+2/3 = ⌥ ↵ ↵ ↵ ↵ ↵ ↵ M(2,2) cR r sR r r M(1,1) cR r cLcR r M(2,2) cL cLsR r sLcR r sLsR r

• ⌦

√

After EW symmetry breaking the charged 2/3 states mix in the basis

states (T2/3, ˜ T, T, t)L,R:

L = g √ 2

• sin θT2/3tR ¯

T5/3γµW +

µ tR + sin θT2/3tL ¯

T5/3γµW +

µ tL

+ sin θTtR ¯ BγµW −

µ tR + sin θTtL ¯

BγµW −

µ tL + h.c.

⇥

T5/3

g √ 2 sin

W +

tR

tR

T2/3

W +

T5/3

T5/3

• > the charged current interaction reads:

SLIDE 14

FCNC : absent for a 4th generation !

˜ T

ZL/h

tL

W +

L

bL

, ,

T

tR

ZL/h

tR

ZL/h

T2/3

B

tR

W −

L

T5/3 W +

L

tR ⌥ Y∗ sin ϕR ⌥ Y∗ sin ϕR

+ Y∗ cos ϕL sin ϕR ⇤ ⌅ ⇤ + Y∗ sin ϕL cos ϕR ⇤

+ Y∗ cos ϕL sin ϕR ⇤ ⌅

• These new fermions couple strongly

to the 3rd generation SM quarks plus one WL , ZL or h

+ Y∗ Tr{ ¯ Q H} ˜ T + h.c

after rotating to mass eigen state basis

Single production and decays proceed via these couplings Pair production proceeds via the usual QCD coupling

e.g

T5/3

g √ 2 sin

W +

tR

tR

T2/3

W +

T5/3

T5/3

tan ϕL = ∆L MQ

tan ϕR = ∆R M ˜

T

SLIDE 15

q g q

T5/3

¯ t

W +

L

λT

Single production also relevant

[Mrazek & Wulzer, ‘09]

B ¯ B

t ¯ t

W + W − W + W −

l+

ν

q ¯ q ¯ q q

l+ b ¯ b

T5/3

¯ T5/3

W + W +

l+

ν ν ν

l+

q ¯ q q ¯ q t ¯ t

b ¯ b

W − W −

✔ For the T5/3 case one can reconstruct the resonant (tW) invariant mass

Look for BB and T5/3 T5/3 in same-sign dilepton final states

_ _ [Contino & Servant, ‘08]

t t

• WW final state

400 600 800 1000 1200 1400 1600 1800 2000 0.1 1 10

MT5/3 [GeV]

!""[fb]

pp ! T5/3 t j +X pp ! T5/3T5/3 +X _

LHC 14 TeV

_

102 103 104

¯ λ = 2, 3, 4

pp → B ¯ t j + X

pp → B ¯ B + X

mB [GeV]

Expected reach at 14 TeV: M~ 1.5 TeV

[Dissertori, Furlan, Moortgat, Nef ‘09] for study at 7 TeV see

SLIDE 16

115 125 135 145 155 165 175 185 0.5 1.0 1.5 2.0 2.5

mKK

[TeV]

mHiggs

[GeV]

12/3 21/6 27/6

] [Contino, Da Rold, Pomarol’06]

Light Higgs wants light top partners

SLIDE 17

lightest fermion: doublet lightest fermion: singlet

⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥

• ⇤

⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤

116 118 120 122 124 126 128 130 500 1000 1500 2000 2500 mHGeV⇥ mTGeV⇥

⇤

12⇤3

• 21⇤6

⇥ 27⇤6

• > partners above

experimental bound

[De Curtis, Redi, Tesi 1110.1613 ]

⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥

• ⇤

⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤

100 120 140 160 180 200 220 240 500 1000 1500 2000 2500 mHGeV⇥ mfGeV⇥

⇤ 12⇤3

21⇤6 ⇥ 27⇤6

moderate mixing

⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥ ⇥

• ⇤

⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤⇤ ⇤ ⇤ ⇤ ⇤ ⇤⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤ ⇤

100 120 140 160 180 200 220 240 500 1000 1500 2000 2500 mHGeV⇥ mfGeV⇥

⇤ 12⇤3

21⇤6 ⇥ 27⇤6

large mixing

f=500 GeV

Light Higgs wants light top partners

f=800 GeV

SLIDE 18

M ˜

T

1000 2000 3000 4000 1000 2000 3000 4000

2006)

MT mH ∈ [115, 130]

[Wulzer,2012]

Light Higgs wants light top partners

[Panico & Wulzer, 1106.2719 ]

SLIDE 19

1000 2000 3000 4000 1000 2000 3000 4000

ξ = 0.1

1000 2000 3000 4000 1000 2000 3000 4000

Exotic bi-doublet is even lighter

M ˜

T

M ˜

T MH ∈ [115 − 130] GeV

[Wulzer,2012]

SLIDE 20

Present constraints: ~ 550-600 GeV on the mass of b’ and t’

[CMS L=1.14 fb-1]

B ¯ B → WtW ¯ t → l±l± b 3j ET

→ lll b 1j ET

PAS-EXO-11-036

mB > 495 GeV

[ATLAS L=1.1 fb-1] [CMS L=1.1 fb-1]

PAS-EXO-11-054

t’b -> bWb ; b’ t -> tbWWbW ; t’ t’ -> bWbW ; b’b’ -> tbWWtbWW

mt’=mb’ > 490GeV

[CMS L=4.7 fb-1]

PAS-EXO-11-099

at least 1 lepton and 4 jets: dilepton

[CMS L=4.7 fb-1]

PAS-EXO-11-050

Mt0 & 552 GeV Mt0 & 560 GeV

update at L=4.6 fb-1 Mb0 & 600 GeV

arXiv:1202.6540 1 lepton:

Mb0 & 480 GeV

same-sign dilepton + 2 jets

Mb0 & 450 GeV

arXiv:1202.5520 arXiv:1202.3389 arXiv:1202.3076 dilepton + 2 jets

Mt0 & 350 GeV

1 lepton:

Mt0 & 404 GeV

[CMS L=1.1 fb-1]

PAS-EXO-11-005

MT & 475 GeV

T->tZ 3 leptons

[ATLAS L=2 fb-1]

arXiv:1204.1265 b’->bZ

Mb0 & 400GeV

SLIDE 21

• pposite-sign

ATLAS limits on t’-> bW (with 1 fb-1)

SLIDE 22

same-sign

ATLAS limits on b’-> tW (with 1 fb-1)

SLIDE 23

CMS limits on t’->bW (with 4.6 fb-1)

larger data set + stronger cuts: stronger limits

400 450 500 550 600

• 1

10 1 [GeV]

t'

M [pb] σ

• bserved 95% C.L.

expected expected σ 1 ± expected σ 2 ±

THEORY

t' )

• 1

), e+jets (4.7fb

• 1

+jets (4.6fb µ :

S

CL CMS preliminary =7 TeV s

Mt0 & 552 GeV

DILEPTON CHANNEL 1 LEPTON + 4 jets CHANNEL

[CMS L=4.7 fb-1]

PAS-EXO-11-050

[CMS L=4.7 fb-1]

PAS-EXO-11-099

Mt0 & 560 GeV

SLIDE 24

CMS limits on b’->tW (with 4.6 fb-1)

DILEPTON CHANNEL

[CMS L=4.6 fb-1]

PAS-EXO-11-036

]

2

[GeV/c

b'

M

450 500 550 600 650

') [pb] b b' → (pp σ

• 2

10

• 1

10 1

expected limit

• bserved limit

theory prediction

2

> 600 GeV/c

b'

Limit at 95% CL: M

σ 2 σ 1

= 7 TeV s

• 1

CMS 2011 Preliminary 4.6 fb

Mb0 & 600 GeV

SLIDE 25

Note: Presented limits assume 100% BR t' -> Wb and 100% BR b' -> Wt Presented limits on b’ apply to vector-like doublets, where B -> tW @ 100%, but not to singlets, which also decay into bZ and bH.

[J-A Aguilar-Saavedra]

Presented limits on t’ apply to charge -4/3 quarks in a doublet, but not to T singlets which also decay into tZ and tH

SLIDE 26

]

2

[GeV/c

T

M 250 300 350 400 450 500 550 X) [pb] T T → (pp σ

• 1

10 1 10

Theory

2

> 475 GeV/c

T

Limit at 95% C.L.: M = 7 TeV s

• 1

CMS 1.14 fb

• bserved limit

σ 1 expected limit σ 2

CMS limits on T->tZ

PRL 107, 271802 (2011)

at the Large Hadron Collider (LHC). The decay pp ! T TX, with T T ! tZ tZ ! b bWþWZZ, Z

SLIDE 27

ATLAS limits on b’->bZ (with 2 fb-1)

[GeV]

b’

m

200 300 400 500 600 700

Zb) [pb]

• (b’
• ×

’) b b’

• (pp
• 2

10

• 1

10 1 10

2

10 (BR = 100%)

• ×

HATHOR

• (BR VLS)
• ×

HATHOR

• expected limit
• bserved limit
• 1

± expected limit

• 2

± expected limit

ATLAS Preliminary

= 7 TeV ) s Data 2011 (

• 1

L dt = 2.0 fb

• M & 400GeV if BR=100%

M & 358GeV if B is singlet mixing with 3rd generation only

b'b' ¡→ ¡Zb + X



to ¡ ¡Z(→

  

' ¡→ ¡



to ¡ ¡Z(→ee) + b-jet

  

with

SLIDE 28

Prospects for T-> tH & B-> bH with H->bb

[Aguilar-Saavedra, 0907.3155]

T ¯ T → Ht W −¯ b → HW +bW −¯ b H → b¯ b, WW → ℓνq¯ q′ , T ¯ T → Ht V ¯ t → HW +b V W −¯ b H → b¯ b, WW → ℓνq¯ q′, V → q¯ q/ν¯ ν B ¯ B → Hb W +¯ t → Hb W +W −¯ b H → b¯ b, WW → ℓνq¯ q′ .

l± + 4b final state

500 1000 1500 2000 2500

HT

50 100 150 200 250

Events / 50 GeV

Ts Bs TBd1 TBd2 XTd BYd SM bkg

l

± (4b)

14 TeV, 30 fb−1

T ¯ T → Ht H¯ t → HW +b HW −¯ b H → b¯ b, WW → ℓνq¯ q′ ,

l± + 6b final state

SLIDE 29

Prospects for T->tH

[Azatov et al, Les Houches report, 1203.1488]

+ 1204.0455

[GeV]

γ 2

M

100 150 200 250 300

Events / 5 GeV

2 4 6 8 10

point A1 point A2 + jets γ W + 2 + jets γ + 2 t t + jets γ + 2 t + t

±

W γ 2 → th, h

• 1

= 14 TeV L= 20.00 fb s Delphes Fast-Simulation 2012

l: thbW/thtZ/thth, h → γγ

SLIDE 30

[Vignaroli 1204.0468]

el pp → ( ˜ B → (h → bb)b)t+X.

pp ! l±+ n jets + 6ET , n 4 , At least 2 b-tag

λ

W

L

q q

• ˜

B t ¯ t

200 300 400 500 600 700 800 900 1 2 3 4 5 mB

é HGeVL

l

s = 8 TeV

5s 15 fb-1 3s 30 fb-1 5s 30 fb-1 15 fb-1 30 fb-1

200 400 600 800 1000 1200 1400 1600 1 2 3 4 5 mB

é HGeVL

l

s = 14 TeV L = 100 fb-1

3s 5s

Prospects for B->bH

SLIDE 31

CMS limit

• n B->tW

[L. Gauthier]

Single production may start to play an important role for M>~600 GeV

λ = MX MW g √ 2 sin θ

q g q′ T5/3/B W +

L / W − L

t t

λ

SLIDE 32

ATLAS search for singly produced vector-like coupled to light quarks

arXiv:1112.5755

• like quarks, Q, coupling to light quarks, q. The s

es, pp → Qq → Wqq′ and pp → Qq → Zqq′ 2011 by the ATLAS experiment at a center-of-m negligible

W/Z l ν/

q W*/Z*

l

Q

l

q q' q" q" q

q

/l ν l W/Z

W*

*

/Z

q' q"

q Q

q

dominant

,leading jet) [GeV]

miss

E m(lepton, 200 400 600 800 1000 1200 Events/50 GeV 2000 4000 6000 8000 10000 12000 14000

Data +jets W t t Single Top Multijet +jets Z Diboson 100 × Signal (600 GeV) Stat + Sys Uncertainty

ATLAS CC Channel = 7 TeV s

• 1

Ldt = 1.04 fb

∫

,leading jet) [GeV]

miss

E m(lepton, 200 400 600 800 1000 1200 Data / BG 0.6 0.8 1 1.2 1.4

D mass [GeV] 200 300 400 500 600 700 800 900 1000 W q) [pb] → BR(D × D q) → (pp σ

• 1

10 1 10

2

10

=1

uD

κ ∼ LO Cross Section, upper limit

s

Expected 95% CL Uncertainty σ 1 ± Uncertainty σ 2 ± Observed Limit

ATLAS = 7 TeV s

• 1

Ldt = 1.04 fb

∫

M > 900 GeV from CC

M > 760 GeV from NC

although new vector quarks expected to couple sizably only to third generation

SLIDE 33

[Bini, Contino , Parisse, Vignaroli, 1110.6058]

q¯ q → G∗ → ˜ T ¯ t + ˜ B¯ b

Associated production (via a heavy gluon)

same final state as tt

• [Contino et al ]

G∗ ˜ T/B

¯ t /¯ b

g3 tan θ3

[Barcelo, Carmona, Masip, Santiago, 1110.5914]

MG∗/M ˜

T ,B

• > model-dependence

Mass reach depends on:

• >Wbt
• >Wtb
• 1000

2000 3000 4000 1 10 10 10 10

• 3
• 2
• 1
• 4

mtot [GeV]

10 10

• 5
• 6

dσ/dmtot [fb/GeV]

mtot ≡ m(WtbtW

6 tb 6 t), at MG∗ = 1.5, 2.0, 3.0 TeV.

⇤

• the ratio
• on coupling between G* and the light fermions,
• on the top degree of compositeness

SLIDE 34

[Bini, Contino , Parisse, Vignaroli, 1110.6058]

q¯ q → G∗ → ˜ T ¯ t + ˜ B¯ b

Associated production (via a heavy gluon)

same final state as tt

• [Contino et al ]

G∗ ˜ T/B

¯ t /¯ b

g3 tan θ3

[Barcelo, Carmona, Masip, Santiago, 1110.5914]

0.0 0.5 1.0 1.5 2.0 2.5 3.0 0.0 0.2 0.4 0.6 0.8 1.0 MGTeV⇤ tan⇥⌅3⌅

s ⇤ 7 TeV L ⇤ 10 fb⇥1

sR⇤1 sR⇤0.8 sR⇤0.6 Discovery Reach

LHC √s = 7 GeV L = 10 fb−1

reach: MT5/3,B ∼ 1.5 TeV

T

• the ratio
• on coupling between G* and the light fermions,
• on the top degree of compositeness

Much better reach ([1 - 1.4 TeV]) in comparison with the previous single+pair production process

MG∗ M ˜

T ,B

∼ 1.5

if

MG∗/M ˜

T ,B

• > model-dependence

Mass reach depends on:

• >Wbt
• >Wtb

SLIDE 35

0.0 0.5 1.0 1.5 2.0 2.5 3.0 0.0 0.2 0.4 0.6 0.8 1.0 MGTeV⇤ tan⇥⌅3⌅

s ⇤ 7 TeV L ⇤ 10 fb⇥1

sR⇤1 sR⇤0.8 sR⇤0.6 1 2 3 4 5 6 0.0 0.2 0.4 0.6 0.8 1.0 MGTeV⇤ tan⇥⌅3⌅

s ⇤ 14 TeV L ⇤ 100 fb⇥1

sR⇤1 sR⇤0.8 sR⇤0.6

[Bini, Contino , Parisse, Vignaroli, 1110.6058]

5 σ discovery region for the signal MG∗/m ˜

T = 1.5 and Y∗ = 3.

G∗ 3

al pp → G∗ → ˜ Tt + Bb → Wtb

5 σ discovery region for the signal

G∗ 3

al pp → G∗ → ˜ Tt + Bb → Wtb

almost 3 TeV reach for top partner!

SLIDE 36

Agashe et al

Other signature: Gluonic resonance

pp → G∗ → t¯ t

decay mainly into tops which have sizable coupling to the strong sector

/ GeV

t t

m 1000 1500 2000 2500 3000 3500 # of events / 200 GeV

2

10

3

10

4

10

jj) ! l b b " t t " (pp

t t

dm # d

• 1

Ldt = 100 fb

$

Signal + Background Background

Possible up to 4 TeV

SLIDE 37

Let us now imagine the top partners are too heavy to be accessible at the LHC (i.e >~1.5-2 TeV), and heavy gluons also too heavy (>~4 TeV ) Where shall we search for signs of top compositeness ?

SLIDE 38

For-top events at t LHC

spectacular events with 12 partons in the final state

SLIDE 39

Four-top production in the Standard Model

t t t t q q

t t t t g g

+ + ....

σLHC ~ 7.5 fb @ 14 TeV

➾ 4 top final state sensitive to several classes of new TeV scale physics 88 %

σLHC ~ 0.2 fb @ 7 TeV

e.g. SUSY (gluino pair production with g → t t χ0) ~

• top compositeness

σtevatron < 10^-4 fb

SLIDE 40

Low energy effective theory approach After integrating out heavy resonances, we are left with higher dimensional operators such as

1 Λ2 (tRγµtR)(tRγµtR)

leading to: well-motivated class of composite higgs models where new heavy resonances have a preference for the top quark

[Pomarol-Serra,’08] [Lillie-Shu-Tait,’08]

t t g g t t X

t t

SLIDE 41

Z’ has suppressed couplings to light quarks

• > no observable resonances

Four-top events from a top-philic and Dark Matter-philic Z’

instead:

Jackson, Servant, Shaughnessy,Tait, Taoso,’09

t t

• ν

ν

• r
• t

t Z’

gg → tt + Z

tt + ET

tttt

Z → νν

Z → t t

(DM) (DM)

t t

SLIDE 42

A simple UV completion

the light mass eigen state identified with top quark is an admixture of t and T

~

Add T (vector-like) charged under U(1)’ with same gauge SM quantum numbers as tR

~

All SM fermions are uncharged under U(1)’ to realize coupling of top quark to Z’ and h:

yHQ3tR + µ ˜ T L ˜ TR + Y Φ ˜ T LtR

higgs of U(1)’

SLIDE 43

mass of Z’ [GeV] 400 600 800 1000 1200 1400 1600 1800 2000 Cross section [pb]

• 4

10

• 3

10

• 2

10

• 1

10 1

tt tt → pp

Z’ 14 TeV Z’ 10 TeV Z’ 7 TeV SM 14 TeV SM 10 TeV SM 7 TeV

production cross section at the LHC

(gZ

tR = 3)

Use top-philic Z’ as benchmark model

SLIDE 44

) [GeV] t M(t 400 600 800 1000 1200 1400 1600 1800

]

• 1

[GeV ) t dM(t

• d
• 1

0.005 0.01 0.015 0.02 0.025 0.03 0.035 0.04 ) [GeV] t M(t 400 600 800 1000 1200 1400 1600 1800

]

• 1

[GeV ) t dM(t

• d
• 1

0.005 0.01 0.015 0.02 0.025 0.03 0.035 0.04

) t distribution of M(t

from the Z’ for M(Z’)=1.2TeV t t for M(Z’)=1.2TeV t spectator t random combination for M(Z’)=1.2TeV SM = 500GeV

• effective model for

t t invariant mass

• mass of Z’ [GeV]

400 600 800 1000 1200 1400 1600

) t maximum of M(t

400 500 600 700 800 900 1000

/ ndf

2

χ 0.2768 / 5

• rigine

74.97 ± 306.5 slope 0.1187 ± 0.3794 / ndf

2

χ 0.2768 / 5

• rigine

74.97 ± 306.5 slope 0.1187 ± 0.3794

)versus m(Z’) t maximum of M(t

for random combination

four-top

SLIDE 45

) [GeV] t M(t 500 1000 1500 2000 normalized to 1 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08

M(Z’) = 1.2 TeV t spectator t random combination tt pp->tt + jets t pp->t

SLIDE 46

) θ cos(

• 1
• 0.8 -0.6 -0.4 -0.2

0.2 0.4 0.6 0.8 1 0.3 0.4 0.5 0.6 0.7 0.8 ) θ cos(

• 1
• 0.8 -0.6 -0.4 -0.2

0.2 0.4 0.6 0.8 1 0.3 0.4 0.5 0.6 0.7 0.8

Polarisation of the top Z’ Model SM

Z’ Model : A=0.78 SM : A=0.50

Z’

M

500 1000 1500 2000 2500

value of A

0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

Z’

Value of the polarisation versus M

top polarization

1 σ dσ d cos θ = A 2 (1 + cos θ) + 1 − A 2 (1 − cos θ)

θ is the angle between the direction of the (highest pT) lepton in the top rest frame and the direction of the top polarisation A: fraction of RH tops In the models of interest, 4-top production yields an excess of right-handed tops

SLIDE 47

background in same-sign dilepton channel @LHC

final state: l± l± + n jets + ET

(of which 4 are b-jets) ➙

tt+jets with charge mis-ID is the main background (more precisely ttbar+ 2 hard jets)

• process

σ [fb] σ.BR(l±l±) [fb] signal m(Z’)=500GeV 838 35 signal m(Z’)=1TeV 61 2.6 signal + 1jet m(Z’)=500GeV 164 6.9 signal + 1jet m(Z’)=1TeV 21.5 0.9 tt¯ tt 7.5 0.3 t¯ tW +W − + 0, 1, 2jets 450 13.7 t¯ tW ± + 0, 1, 2, 3jets 595 18.4 W +W −W ± + 0, 1, 2jets 603 18.7 W ±W ± + 0, 1, 2, 3jets 340 15.5 t¯ t 442 657 203 t¯ t + 1 jet 315 999 145 t¯ t + 2 jets 182 868 84 t¯ t + 3 jets 101 057 46 t¯ t + 4 jets 36 236 17

SLIDE 48

>30GeV

T

total number of jets if P 2 4 6 8 10 12 14 dN σ d σ 1 0.05 0.1 0.15 0.2 0.25

= 500 GeV

Z’

M = 1 TeV

Z’

M background

>30GeV

T

number of b-jets if P 1 2 3 4 5 6 7 dN σ d σ 1 0.1 0.2 0.3 0.4 0.5 0.6 = 500 GeV

Z’

M = 1 TeV

Z’

M background

# of jets

SLIDE 49

[GeV]

T

H 500 1000 1500 2000 2500 dN σ d σ 1 0.05 0.1 0.15 0.2 0.25 0.3 t t + 1 jet t t + 2 jets t t + 3 jets t t + 4 jets t t [GeV]

T

H 500 1000 1500 2000 2500 3000 3500 dN σ d σ 1 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 0.2 0.22

= 500 GeV

Z’

M = 1 TeV

Z’

M background

Distinguishing variable

SLIDE 50

g nj ≥ 6, pT > 30 GeV

nb jets 3

[GeV]

tot

M 1000 2000 3000 4000 5000 6000 7000 8000 Number of events 5 10 15 20 25 30 35 40 45

=14TeV s ,

• 1

L = 10fb background, b-efficiency=1 signal, b-efficiency=1 background, b-efficiency=0.6 signal, b-efficiency=0.6

= 500 GeV

Z’

M [GeV]

tot

M 1000 2000 3000 4000 5000 6000 7000 8000 Number of events 0.5 1 1.5 2 2.5 3 3.5 4 4.5

=14TeV s ,

• 1

L = 10fb background, b-efficiency=1 signal, b-efficiency=1 background, b-efficiency=0.6 signal, b-efficiency=0.6

= 1 TeV

Z’

M

HT & 1.2 TeV

HT & 700 GeV

4-top production cross section: ~ 800 fb 4-top production cross section: ~ 60 fb

∼ 2 σ

5σ excess luminosity ~ 45 fb-1 5σ excess luminosity ~ 1 fb-1

∼ 20 σ

SLIDE 51

With cut nbjet ≥ 6 and nbbjet ≥ 3 :

hadronic top + leading lepton + b-jet) [GeV]

st

(1

inv

M 500 1000 1500 2000 number of events 0.5 1 1.5 2 2.5 3 =14TeV s ,

• 1

L = 10fb =500GeV

Z’

signal M background

• nly

t t

top reconstruction

e after finding the 2 leptonic tops

number of distinct hadronic tops 1 2 number of events 1 10

2

10

3

10

4

10 =14TeV s ,

• 1

L = 10fb =500GeV

Z’

signal M background

• nly

t t number of distinct tops

• 0.5

0.5 1 1.5 2 2.5 3 3.5 4 4.5 number of events

• 2

10

• 1

10 1 10

2

10

3

10

4

10

=14TeV s ,

• 1

L = 10fb =500GeV

Z’

signal M background

• nly

t t

SLIDE 52

) θ cos(

• 1 -0.8 -0.6 -0.4 -0.2

0.2 0.4 0.6 0.8 1 0.3 0.4 0.5 0.6 0.7 0.8 ) θ cos(

• 1 -0.8 -0.6 -0.4 -0.2

0.2 0.4 0.6 0.8 1 0.3 0.4 0.5 0.6 0.7 0.8

Polarisation of the top Z’ Model SM

Z’ Model : A=0.78 SM : A=0.50

pola_top Entries 6085 Mean 0.09888 RMS 0.556

) θ cos(

• 1
• 0.8 -0.6 -0.4 -0.2

0.2 0.4 0.6 0.8 1 0.2 0.3 0.4 0.5 0.6 0.7 0.8

pola_top Entries 6085 Mean 0.09888 RMS 0.556

Signal Background

polarisation of the top

Back to top polarisation (requires top momentum reconstruction) at generator level after top reconstruction in 1-lepton channel

SLIDE 53

[GeV]

T

H 500 1000 1500 2000 2500 3000 3500 4000 4500 dN σ d σ 1 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18

=500GeV

Z’

Z’ model M =1TeV

Z’

Z’ model M =800GeV

Gluino

Susy M = 500GeV Λ effectif model )=500GeV

5/3

exotic model M(T background

four-top events from different models

SLIDE 54

four-top events from gluino pair production is easily distinguishable

[GeV]

miss T

E 100 200 300 400 500 600 700 800 900 1000 dN σ d σ 1 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09

=500GeV

Z’

Z’ model M =1TeV

Z’

Z’ model M =800GeV

Gluino

Susy M = 500GeV Λ effectif model )=500GeV

5/3

exotic model M(T background

large E_Tmiss

SLIDE 55

four-top events from gluino pair production

{GeV}

miss T

E 200 400 600 800 1000 1200 1400 1600 dN σ d σ 1 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16

signal + jets t pp->t

M=800 GeV

[GeV]

miss T

E 100 200 300 400 500 600 700 800 900 1000 dN σ d σ 1 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09

=500GeV

Z’

Z’ model M =1TeV

Z’

Z’ model M =800GeV

Gluino

Susy M = 500GeV Λ effectif model )=500GeV

5/3

exotic model M(T background

SLIDE 56

process σ [fb] σ.BR(l±l±) [fb] signal m(Z’)=500GeV 41 1.7 tt¯ tt 0.74 0.031 t¯ t 93 142 42.7 t¯ t + 1 jet 71 746 32.90 t¯ t + 2 jets 37 190 17.06 t¯ t + 3 jets 15 851 7.27 t¯ t + 4 jets 4 215 1.93

[GeV]

tot

M 500 1000 1500 2000 2500 3000 3500 4000 Number of events 0.5 1 1.5 2 2.5 3

=14TeV s ,

• 1

L = 10fb background, b-efficiency=1 signal, b-efficiency=1 background, b-efficiency=0.6 signal, b-efficiency=0.6

and nbjets ≥ 6, nbbjets ≥ 3, HT > 500GeV

four-top events at 7 TeV

S= 3 B= 0.3 with 10 /fb:

SLIDE 57

Te top quark-Dark Mater connection

if the WIMP hypothesis is correct: likely to be connected to the physics of EW symmetry breaking and Dark Matter may have enhanced couplings to massive states

SLIDE 58

L = LSM − 1 4F

µνF µν + M 2 ZZ µZµ + i¯

νγµDµν + gt

R¯

tγµPRZµt + χ 2 F

µνF µν Y

Dµ ≡ ∂µ − i (gν

RPR + gν LPL) Zµ

A very simple effective theory

The WIMP is a Dirac fermion, ν, singlet under the SM, charged under a new spontaneously broken U(1)’. The only SM particle charged under the Z’ is the top quark There is no SM state the WIMP can decay into: ν is stable. This model can be UV completed as an SO(10) RS model

Agashe-Servant ’04

More generally, in models of partial fermion compositeness, natural to expect that only the top couples sizably to a new strongly interacting sector.

see also Belanger-Pukhov-Servant ’07 Jackson, Servant, Shaughnessy,Tait, Taoso,’09

SLIDE 59

Z, Z’

• h

t

• ~ O(1) couplings

Dirac Dark Matter annihilation into γ H

Jackson, Servant, Shaughnessy,Tait, Taoso,’09

Eγ = MDM

• 1 −

M 2

X

4M 2

DM

⇥

DM DM

Seeing the light from Dark Matter

SLIDE 60

NFW profile adiabatically contracted

γ-ray lines from the Galactic Center ΔΩ℧= 10-5 sr

Spectra for parameters leading to correct relic density and satisfying direct detection constraints

Mn=149 GeV Hgn

Z'=gt Z'=3L Mn=162 GeV Hgn Z'=gt Z'=1L

g h

• Mh=170 GeV

g Z¢- MZ'=220 GeV g Z

HESS EGRET FERMI

1 10 102 10-16 10-15 10-14 10-13 10-12 10-11 10-10 10-9 10-8 10-7 10-6 10-5 10-4 Eg @GeVD E2dFêdE @GeV cm-2s-1D

Jackson, Servant, Shaughnessy,Tait, Taoso,’09

Highs in Space!

Z’ H Z

SLIDE 61

[Weniger 1204.2797]

“A Tentative γ-Ray Line With E~ 130 GeV from Dark Matter Annihilation at the Fermi Large Area Telescope.” and a very recent claim ...

Z’ H Z

Mn=149 GeV Hgn

Z'=gt Z'=3L Mn=162 GeV Hgn Z'=gt Z'=1L

g h

• Mh=125 GeV

g Z¢- MZ'=220 GeV g Z

HESS EGRET FERMI

1 10 102 10-16 10-15 10-14 10-13 10-12 10-11 10-10 10-9 10-8 10-7 10-6 10-5 10-4 Eg @GeVD E2dFêdE @GeV cm-2s-1D

The additional line due to Z’ disappears if the Z’ is heavier than 300 GeV

Jackson, Servant, Shaughnessy,Tait, Taoso,’09

SLIDE 62

If gauge resonances are heavier

• > Effective Field

Theory (EFT) approach

SLIDE 63

EW precision data together with constraints from flavour physics make plausible if not likely that there exists a mass gap between the SM degrees

• f freedom and any new physics threshold.

2 2

1 p M #

g g

SM

2 2

g M

2 2 SM

g L L M !!!! " # dim " 6

effective 4-fermion interaction @ E<M In this case, new physics can be integrated out and simply gives new (higher dimensional) interactions among the SM degrees of freedom

in the rest of the talk: no bias on what the TeV new physics should be

SLIDE 64

Low-energy effective field theory approach to BSM

New interactions are assumed to respect all symmetries of the SM.

Buchmuller-Wyler ‘86

2 i SM i i

c L L O ! " #

$

dim ! 4 ( 6

c 60 &

• perators

:

Good news: Only a few operators contribute to top quark physics

SLIDE 65

Our goal: study new physics in tt final state in the most general model-independent approach

SLIDE 66

Zhang & Willenbrock’10, Aguilar-Saavedra ‘10 , Degrande & al ’10 ...

Dimension 6 operators for top physics

There are only 15 relevant operators:

ner

• perator

process O(3)

φq = i(φ+τIDµφ)(¯

qγµτIq) top decay, single top OtW = (¯ qσµντIt)˜ φW I

µν (with real coefficient)

top decay, single top O(1,3)

qq

= (¯ qiγµτIqj)(¯ qγµτIq) single top OtG = (¯ qσµνλAt)˜ φGA

µν (with real coefficient)

single top, q¯ q, gg → t¯ t OG = fABCGAν

µ GBρ ν GCµ ρ

gg → t¯ t OφG = 1

2(φ+φ)GA µνGAµν

gg → t¯ t 7 four-quark operators q¯ q → t¯ t

• perator

process OtW = (¯ qσµντ It)˜ φW I

µν (with imaginary coefficient)

top decay, single top OtG = (¯ qσµνλAt)˜ φGA

µν (with imaginary coefficient)

single top, q¯ q, gg → t¯ t O ˜

G = gsfABC ˜

GAν

µ GBρ ν GCµ ρ

gg → t¯ t Oφ ˜

G = 1 2(φ+φ) ˜

GA

µνGAµν

gg → t¯ t

CP-even CP-odd

We will only consider those which affect top pair production at tree level by interference with the SM (QCD) amplitudes (we neglect weak corrections)

chg

cV v

cAv

cAa

h

SLIDE 67

Zhang & Willenbrock’10, Aguilar-Saavedra ‘10 , Degrande & al ‘10

Dimension 6 operators for top physics

There are only 15 relevant operators:

ner

• perator

process O(3)

φq = i(φ+τIDµφ)(¯

qγµτIq) top decay, single top OtW = (¯ qσµντIt)˜ φW I

µν (with real coefficient)

top decay, single top O(1,3)

qq

= (¯ qiγµτIqj)(¯ qγµτIq) single top OtG = (¯ qσµνλAt)˜ φGA

µν (with real coefficient)

single top, q¯ q, gg → t¯ t OG = fABCGAν

µ GBρ ν GCµ ρ

gg → t¯ t OφG = 1

2(φ+φ)GA µνGAµν

gg → t¯ t 7 four-quark operators q¯ q → t¯ t

• perator

process OtW = (¯ qσµντ It)˜ φW I

µν (with imaginary coefficient)

top decay, single top OtG = (¯ qσµνλAt)˜ φGA

µν (with imaginary coefficient)

single top, q¯ q, gg → t¯ t O ˜

G = gsfABC ˜

GAν

µ GBρ ν GCµ ρ

gg → t¯ t Oφ ˜

G = 1 2(φ+φ) ˜

GA

µνGAµν

gg → t¯ t

CP-even CP-odd

We will only consider those which affect top pair production at tree level by interference with the SM (QCD) amplitudes (we neglect weak corrections)

chg

cV v

cAv

cAa

h top-philic operators: modifying top couplings and not only-gluon couplings

SLIDE 68

Effective Field Theory for Top Quark Pair production

Degrande & al ‘10

We focus on top-philic new physics (and therefore ignore interactions that would

• nly affect the standard gluon vertex )

We are left with only two classes of dim-6 gauge invariant operators (when working at order O(1/Λ2))

|M|2 = |MSM|2 + 2(MSMM∗

NP) + O

1 Λ4

• We calculate top pair production at order O(1/

Λ2)

i.e. we assume new physics manifests itself at low energy only through

• perators interfering with the SM

r OG = fABCGA

µνGB νρGC ρ µ

ction). Hence we consider t

SLIDE 69

Effective Field Theory for Top Quark Pair production

however only 7 independent

• perators

O(8,1)

Qq

= ¯ QγµT AQ

• ¯

qγµT Aq

• ,

O(8,3)

Qq

= ¯ QγµT AσIQ

• ¯

qγµT AσIq

• ,

O(8)

tu

= ¯ tγµT At

• ¯

uγµT Au

• ,

O(8)

td

= ¯ tγµT At ¯ dγµT Ad

• ,

O(8)

Qu

= ¯ QγµT AQ

• ¯

uγµT Au

• ,

O(8)

Qd

= ¯ QγµT AQ ¯ dγµT Ad

• ,

O(8)

tq

=

• ¯

qγµT Aq ¯ tγµT At

• ,

O(8)

d

= ¯ QT At

• ¯

qT Ad

• ,

¯ LL¯ LL:

¯ RR ¯ RR:

¯ LL ¯ RR:

¯ LR¯ LR:

• 4-fermion op.

: negligible (QCD is chirality diagonal)

q q − t t −

• Ohg

=

• H ¯

Q

• σµνT At
• GA

µν

• op. with t, t and one or

two gluons (chromomagnetic moment)

• t

t − g g t t − g

We are left with only two classes of dim-6 gauge invariant operators (when working at order O(1/Λ2))

SLIDE 70

+ + SM SM SM + + + g g t ¯ t +

t t − g g t t − g

Chromomagnetic operator Ohg = (H ¯ Q)σµνT At GA

µν q q − t t −

Four-fermion operators

|M|2 = |MSM|2 + 2(MSMM∗

NP) + O

1 Λ4

• top pair production in EFT at order O(1/Λ2)

we assume new physics manifests itself at low energy only through operators interfering with the SM

+ + q ¯ q t ¯ t SM

New vertices: top pair production from gluon fusion: corrections from chg only top pair production from q anti-q annihilation: corrections from both chg and 4-fermion operators

SLIDE 71

dt → 9s

• 2
• dσSM

dt (gg → t¯ t) = πα2

s

s2

• 1

6τ1τ2 − 3 8

• (ρ + τ 2

1 + τ 2 2 −

ρ2 4τ1τ2 )

dσ dt (gg → t¯ t) = dσSM dt + √ 2αsgs vmt s2 chg Λ2

• 1

6τ1τ2 − 3 8

• Common factor mainly

responsible for the shape

• f the distributions

τ1 = m2

t − t

s , τ2 = m2

t − u

s , ρ = 4m2

t

s .

The new physics and SM contributions for gluon fusion have a common factor

The operator Ohg can hardly be distinguished from the SM in gluon fusion

gluon fusion

Distortions in the shape of the distributions can only come from q q annihilation ➙ small effect at LHC

• t: Mandelstam variable

related to θ angle (between incoming parton and outgoing top quark)

m2

t − t = s

2 (1 − β cos θ) .

(contribution from one operator only)

SLIDE 72

q q annihilation

• Only two linear combinations of 4-fermion operators actually contribute to

the differential cross section after averaging over the final state spins

dσ dt (q¯ q → t¯ t) = dσSM dt

• 1 + cV v ±

c

V v

2

g2

s

s Λ2

• + 1

Λ2 αs 9s2

• cAa ± c

Aa

2

• s(τ2 − τ1) + 4gschg

√ 2vmt

• even part in the

scattering angle θ

• dd part in the

scattering angle θ ¯ tγµT At¯ qγµT Aq comes from comes from

¯ tγµγ5T At¯ qγµγ5T Aq.

This dependence vanishes after integration over t

some axial combination of

• perators is asymmetric

under q <-> q

• some vector combination
• f operators that is

symmetric under q <-> q

• with

cRv = ctq/2 + (ctu + ctd)/4 cLv = c(8,1)

Qq /2 + (cQu + cQd)/4

vector combination of the light quarks involving the RH and LH top quarks axial combination of the light quarks involving the RH and LH top quarks

with cRa = −ctq/2 + (ctu + ctd)/4 cLa = −c(8,1)

Qq /2 + (cQu + cQd)/4.

(contribution from the 8 operators)

cAa = cRa − cLa

cV v = cRv + cLv

←u+d→ ←u-d→

c

V v = (ctu − ctd)/2 + (cQu − cQd)/2 + c(8,3) Qq ,

c

Av = (ctu − ctd)/2 − (cQu − cQd)/2 − c(8,3) Qq

SLIDE 73

LHC 7 TeV

total cross section

Tevatron

σ (pp → t¯ t) /pb = 6.15+2.41

−1.61 +

• 0.87+0.23

−0.16

• cV v +
• 1.44+0.47

−0.33

• chg +
• 0.31+0.08

−0.06

• c

V v

• 1 TeV

Λ 2 .

u+d (isospin 0) chromo magnetic moment u-d (isospin 1) σ (pp→t¯ t) /pb=94+22

−17+

• 4.5+0.7

−0.6

• cV v+
• 25+7

−5

• chg+
• 0.48+0.068

−0.056

• c

V v

• 1 TeV

Λ 2 .

• σ (pp → t¯

t) /pb = 538+162

−115 +

• 15+2

−1

• cV v +
• 144+34

−25

• chg +
• 1.32+0.12

−0.12

• c

V v

• 1 TeV

Λ 2 .

LHC 14 TeV

LO with CTEQ6L1 pdfs In fits, we’ll use NLO+NLL SM results but in interference, we’ll keep LO SM amplitude

SLIDE 74

Tevatron constraints

Region allowed by the Tevatron at 2 σ

chg × (1 TeV/Λ)2 cVv × (1 TeV/Λ)2

4 2

• 2
• 4
• 4
• 2

2

total cross section

Ohg

(chromomagnetic moment operator) (4-fermion

• perator)

The pp -> tt total cross section at Tevatron depends on both chg and cVv and constrains thus a combination of these parameters.

SLIDE 75

Tevatron constraints

The pp -> tt total cross section at Tevatron depends on both chg and cVv and constrains thus a combination of these parameters.

• Ohg

(chromomagnetic moment operator) (4-fermion

• perator)

chg × (1 TeV/Λ)2 cVv × (1 TeV/Λ)2

4 2

• 2
• 4
• 4
• 2

2

Region allowed by the Tevatron at 2 σ

tt invariant mass shape

SLIDE 76

The LHC - Tevatron complementarity

4 2 2 4 4 2 2 4 chg 1TeV2 cVv 1TeV2

10 10 20 20

Ohg

(chromomagnetic moment operator) (4-fermion

• perator)
• At the LHC, the pp -> tt total cross section mostly depends on chg and

can be directly used to constrain the allowed range for chg

• The Tevatron cross section depends on both chg and cVv and

constrains thus a combination of these parameters. Region allowed by the Tevatron at 2 σ total cross section tt invariant mass shape LHC total cross section limits (7 TeV: thin line, 14 TeV: thick line)

SLIDE 77

The LHC - Tevatron complementarity

Ohg

(chromomagnetic moment operator) (4-fermion

• perator)
• At the LHC, the pp -> tt total cross section mostly depends on chg and

can be directly used to constrain the allowed range for chg

• The Tevatron cross section depends on both chg and cVv and

constrains thus a combination of these parameters.

• tt invariant

mass shape LHC total cross section limits (assuming no deviations

• bserved compared to SM prediction)

total cross section

chg × (1 TeV/Λ)2 cVv × (1 TeV/Λ)2

4 2

• 2
• 4
• 4
• 2

2 4

SLIDE 78

yellow region is excluded by Tevatron green (blue) region excluded by LHC at 7 TeV (14 TeV) after a precision

• f 10% is reached on σtt

4 2 2 4 4 2 2 4 chg 1TeV2 cVv 1TeV2

Tevatron LHC 7TeV LHC 14TeV

20 10 10 20 20 10 10 20

measured σtt = σSM

[Degrande, Maltoni, Gérard, Grojean, Servant’10]

Constraining Non-resonant New Physics in top pair production

A 10% uncertainty on the total cross section at the LHC already rules out a large region of parameter space

Ohg

(chromomagnetic moment operator) (4-fermion

• perator)

SLIDE 79

300 400 500 600 700 800 900 1000 0.00 0.05 0.10 0.15 0.20 mttGeV 1 Σ

• dΣ

d mtt

SM cVv 2, chg1, 1 TeV

100 200 300 400 500 0.00 0.02 0.04 0.06 0.08 0.10 0.12 0.14 pTGeV 1 Σ

• dΣ

d pT

SM cVv 2, chg1, 1 TeV

4 2 2 4 0.00 0.02 0.04 0.06 0.08 0.10 Η 1 Σ

• dΣ

d Η

SM cVv 2, chg1, 1 TeV

300 400 500 600 700 800 900 1000 0.00 0.05 0.10 0.15 0.20 mttGeV 1 Σ dΣ d mtt

SM Ohg ORvOLv

100 200 300 400 500 0.00 0.02 0.04 0.06 0.08 0.10 0.12 0.14 pTGeV 1 Σ

• dΣ

d pT

SM Ohg ORvOLv

4 2 2 4 0.00 0.02 0.04 0.06 0.08 0.10 Η 1 Σ dΣ d Η

SM Ohg ORvOLv

Minor effect on shapes of distributions at the LHC

SLIDE 80

1000 1500 2000 2500 3000 3500 4000 6 5 4 3 2 1 MW Σpb W' Operators

Domain of validity of results

At the Tevatron, our results apply to a region of parameter space bounded by 2) For which typical mass scale does the effective field theory treatment apply?

• > ~ 1.5 TeV

1) when O(1/Λ4) terms are subdominant

|ci| TeV Λ ⇥2 7 |chg| TeV Λ ⇥2 3 |cV v| TeV Λ ⇥2 2

At the LHC, since the center of mass energy is larger, the reliable region shrinks to and

correction to SM cross section at the LHC due to a W’ and comparison with EFT computation

SLIDE 81

1000 1500 2000 2500 3000 3500 4000 0.14 0.12 0.10 0.08 0.06 0.04 0.02 0.00 MA AFB Axigluon Operators

Effective Field Theory Approach to the Forward-Backward asymmetry

AF B ≡ σ (cos θt > 0) − σ (cos θt < 0) σ (cos θt > 0) + σ (cos θt < 0)

ASM

F B = 0.05 ± 0.015.

AEXP

F B = 0.15 ± 0.05(stat) ± 0.024(syst),

C Aa and C ’Aa are only constrained by the asymmetry and not by the total cross section or the invariant mass distribution Link to axigluon models:

: cAa/Λ2 = −2gq

Agt A/m2 A

⇔

• > top quarks are preferentially emitted in the direction of the incoming quark

dσ dt (q¯ q → t¯ t) = dσSM dt

• 1 + cV v ±

c

V v

2

g2

s

s Λ2

• + 1

Λ2 αs 9s2

• cAa ± c

Aa

2

• s(τ2 − τ1) + 4gschg

√ 2vmt

• [Degrande, Maltoni, Gérard,

Grojean, Servant’10] AFB prediction at the Tevatron due to an axigluon and comparison with the EFT computation

δAdim 6

F B

=

• 0.0342+0.016

−0.009 cAa + 0.0128+0.0064 −0.0036 c Aa

• ×

1 TeV Λ 2

SLIDE 82

inclusive Mtt < 450 GeV Mtt > 450 GeV

• 10
• 8
• 6
• 4
• 2

2 4

• 10

10 20 30 CAa ¥ TeV2êL2 C'Aa ¥ TeV2êL2

δA(mt¯

t < 450 GeV) =

• 0.023+3

−1c Aa + 0.0081+6 −4c

Aa

1 TeV Λ 2 , δA(mt¯

t 450 GeV) =

• 0.087+10

−9 c Aa + 0.032+4 −3c

Aa

1 TeV Λ 2 .

( [Degrande et al’10,’11]

(using CDF data)

Including O(Λ-4 ) terms can alleviate the tension. See analysis by Aguilar-Saavedra & Perez-Victoria,1103.2765 and Delaunay et al, 1103.2297. Most general expression at order O(Λ-2 )

σ(t¯ t) = σSM + δσint + δσquad

δσint + δσquad 0

This requires Anew ∼ −2ASM tt tail at LHC

• more details in JA Aguilar-Saavedra’s talk

consistent to ignore SM×Dim 8 terms if c is large

SLIDE 83

Spin correlations

• 4. The three observables σ, dσ/dmt¯

t and AF B are unable to disentangle between theories

coupled mainly to right- or left-handed top quarks. However, spin correlations allow us to determine which chiralities of the top quark couple to new physics, and in the case

• f composite models, whether one or two chiralities of the top quark are composite.

1 σ dσ d cos θ+d cos θ− = 1 4 (1 + C cos θ+ cos θ− + b+ cos θ+ + b− cos θ−)

+

re θ+ (θ−) is the angle between the charged lepton l+ (l−) resulting from the top (antitop)

• +

−

decay and some reference direction a ( b).

• C

= 1 σ (σRL + σLR − σRR − σLL) , b+ = 1 σ (σRL − σLR + σRR − σLL) , b− = 1 σ (σRL − σLR − σRR + σLL) .

C × σ/pb = 2.82+1.06

−0.72 +

• 0.37+0.10

−0.08

• chg +
• 0.50+0.13

−0.10

• cV v
• ×

1 TeV Λ 2 , b × σ/pb =

• 0.45+0.12

−0.09

• cAv ×

1 TeV Λ 2 ,

e cRv −cLv

proportional to allows to distinguish between LH and RH quarks

SLIDE 84

4 2 2 4 4 3 2 1 1 2 chg 1TeV2 cVv 1TeV2

∆C at the Tevatron

0.15 0.1 0.05 0.05 0.1 0.15

4 2 2 4 4 3 2 1 1 2 chg 1TeV2 cAv 1TeV2

b at the Tevatron

0.3 0.2 0.1 0.1

2 1 1 2 2 1 1 2 chg 1TeV2 cVv 1TeV2

∆C at the LHC

0.05 0.05 0.1 0.15 0.2 0.25

2 1 1 2 2 1 1 2 chg 1TeV2 cAv 1TeV2

b at the LHC

0.025 0.025 0.05

SLIDE 85

SM at the Tevatron

1 1

cosΘ

1 1

cosΘ

0.005 0.01 0.015 cRv2, cLv0, chg1 and 1 TeV at the Tevatron 1 1

cosΘ

1 1

cosΘ

0.005 0.01 0.015

SM at the LHC

1 1

cosΘ

1 1

cosΘ

0.005 0.01 0.015

cRv2, cLv0, chg1 and 1 TeV at the LHC

1 1

cosΘ

1 1

cosΘ

0.005 0.01 0.015

Figure 11: Distribution of events at the Tevatron/LHC (top panel/bottom panel) for the SM (on

the left) and for cRv = −2, cLv = 0, chg = 1 and Λ = 1 TeV (on the right) with µF = µR = mt.

Spin correlations

SLIDE 86

Summary

σ(gg → t¯ t), dσ(gg → t¯ t)/dt ↔ chg σ(q¯ q → t¯ t) ↔ chg, cV v dσ(q¯ q → t¯ t)/dmtt ↔ chg, cV v AF B ↔ cAa spin correlations ↔ chg, cV v, cAv

Non-resonant top philic new physics can be probed using measurements in top pair production at hadron colliders This model-independent analysis can be performed in terms of 8 operators. Observables depend on different combinations of only 4 parameters:

SLIDE 87

• Ref. [24]
• Ref. [19]
• Ref. [51]
• Ref. [20]
• Ref. [21]

chg 2CtG g1gs

1 2C33 uGφ

cV v

1 4

• C1

u+C2 u+C1 d+C2 d

• −g2g2

s(*) g2

s

4 (κu R+κd R+κu L+κd L)(*) g2

s

2 (C1+C2)

cAa

1 4

• C1

u−C2 u+C1 d−C2 d

• g2

s

4 (κu R+κd R+κu L+κd L)(*) g2

s

2 (C1−C2)

c

V v 1 2

• C1

u+C2 u−C1 d−C2 d

• g2

s

2 (κu R−κd R+κu L−κd L)(*)

c

Aa 1 2

• C1

u−C2 u−C1 d+C2 d

• g2

s

2 (κu R−κd R+κu L−κd L)(*)

Jung et al, 0912.1105 Hioki et al, 0910.3049 Kumar et al, 0901.3808 Zhang et al, 1008.3869 Cao et al, 1003.3461

Note: Previous studies had looked at the phenomenology of part of the operators

Listed all operators although did not study the phenomenology

e.g:

SLIDE 88

u d, s, b t u d, s, b t W W Effective Field Theory Approach to Same-sign top pair production

SM contribution to uu->tt ~ |Vub|4 Like-sign top pair production is a golden channel for early discovery at the LHC uu->tt is absent in the SM at tree level

SLIDE 89

ORR =

¯

tRγ µuR

• [¯

tRγµuR],

O(1)

LL =

¯

Q Lγ µqL

• [ ¯

Q LγµqL],

O(3)

LL =

¯

Q Lγ µσ aqL

¯

Q Lγµσ aqL

• ,

O(1)

LR =

¯

Q Lγ µqL

• [¯

tRγµ uR],

O(8)

LR =

¯

Q Lγ µT AqL

¯

tRγµ T AuR

• Lqq→tt

dim=6 = 1

Λ2

• cRRORR + c(1)

LL O(1) LL + c(3) LL O(3) LL

• + c(1)

LR O(1) LR + c(8) LR O(8) LR

+ h.c.

Five Effective Operators for Same-Sign Top-Pair Production

u u t t

Degrande et al, 1104.1798 Aguilar-Saavedra, 1008.3562

OLL and OLL contain which contributes to Bd mixing and are therefore constrained: |cLL| (1 TeV/Λ)2 < 2.1 10-4

(1)

cLL =cLL + cLL

(1) (3)

][¯ ]

n [¯ bLγ µdL][¯ bLγµdL], di-jet production. For

(3)

SLIDE 90

pp -> tt cross section

dσ dt = 1

Λ4

• |cRR|2 + |cLL|2(s − 2m2

t )

3πs

+

• c(1)

LR

• 2 + 2

9

• c(8)

LR

• 2

(m2

t − t)2 + (m2 t − u)2

16πs2

−

• c(1)

LR

• 2 + 8

3

• c(1)

LR c(8) LR

∗

− 2

9

• c(8)

LR

• 2

m2

t

24πs

• .

σ grows like ~ s ~ mt2 A large part of the cross section at the LHC comes from the region where mtt ~ 1 TeV, where the 1/Λ cannot be trusted for Λ ~ 1TeV

1000 2000 3000 4000 5000 5104 0.100 0.050 0.010 0.005 0.001 mttGeV 1 Σ

• dΣ

d mtt

ORR ; OLL

1 ; OLL 3

ORL

1

ORL

8

ORL

1 2 ORL 8

t t : int. 4 F t t : SM

7 TeV

tt tt

• ( no such concern at the

Tevatron where mtt <~ 500 GeV)

SLIDE 91

2 4 6 8 10 12 14 1 5 10 50 100 500 1000 TeV Σ mtt3fb

ORR ; OLL

1 ; OLL 3

ORL

1

ORL

8

• Int. ORL

1 ORL 8

7 TeV

ci = 1 σpp->tt with an upper cut on Mtt For Λ ~ 2 TeV and c~ 1, cross sections are of order O(pb) at 7 TeV

SLIDE 92

1

σ

dσ d cosθ1d cosθ2

= 1

4

• 1 + C cosθ1 cosθ2
• + b(cosθ1 + cosθ2),

C = 1

σ (σ++ + σ−− − σ+− − σ−+),

b = 1

σ (σ++ − σ−−),

ORR C = 1 b = 0.997 O(1)

LL, O(3) LL

C = 1 b = −0.997 O(1)

LR, O(8) LR

C ≈ 1 b ≈ 0

Spin correlations

Very efficient to discriminate among the contributions from the various operators which have a well-defined chirality structure and no interference with the SM is possible

SLIDE 93

Spin SU(3) SU(2) Y cRR c(1)

LL

c(3)

LL

c(1)

LR

c(8)

LR

1 ¯ 3 2

5 6

−1

6 1 2

1 6 2

5 6

−1

3

−1

2

6 1

4 3 1 4

6 3

1 3

−3

8

−1

8

Spin SU(2) Y cV v c

V v

cAa c

Aa

1 1 −1

2

−1 −1

2

−1 2

1 2

−1

2

• |ξ|2 + 1

2

• −1

2 1 2

• |ξ|2 + 1

2

• 1

2

Spin SU(3) SU(2) Y cRR c(1)

LL

c(3)

LL

c(1)

LR

c(8)

LR

1 1 1 −1

2

−ξ2

2

−ξ 1 8 1 −1

6

− ξ2

24

−ξ2

8

−ξ 1 2

1 2

−1

6ξ

−ξ 8 2

1 2

−2

9ξ 1 6ξ

1 1 3 −ξ2

2

1 8 3 −3

8ξ2 5 24ξ2

u u t t u ¯ u t ¯ t Q = 4

3

6, ¯ 3 Q = 0 1, 8

u 8, 1 Q = 0 8, 1 Q = 0 u t t u ¯ u ¯ t t

Link to resonant models

t-channel s-channel link to AFB in ttbar In general, no relation exists between same and opposite sign top pair production i.e. cRR , cLL , cLR , cLR cannot be related to cVv, cAa

(1) (8)

Lq¯

q→t¯ t =

cV v

2

±

c

V v

4

¯

tγµT at

¯

qγµT aq

• +

c Aa

2 ± c

Aa

4

¯

tγµγ5T at

¯

qγµγ5T aq

• ,

|cVv|=|cAa|, |c’Vv|=|c’Aa|

SLIDE 94

Connection with composite top models In models of composite tops, the operators contributing directly to top pair production are subdominant compared to four-top operators (from Naive Dimensional Analysis) In this case, a much better probe of the dominant dynamics is the direct production of four top quarks typical LHC cross sections at 14 TeV: 10 - 100 fb

1 Λ2 (tRγµtR)(tRγµtR)

t t g g t t X

t t

• [Pomarol, Serra’08]

[Lillie, Shu, Tait ’08]

spectacular events with 12 partons in the final state (The dominant operators are those which contain only fields from the strong sector, scale as )

g2

ρ

gρ

g−1

ρ

4-fermion op. contributing directly to tt production scale at best as while Ohg scales as

• coupling of the

strong sector

1 gρ 4π

SLIDE 95

OR =(¯ tγµt)(¯ tγµt) .

the color octet (O(8)

R = 1/3OR

O(1)

L =

¯ QγµQ ¯ QγµQ

• O(8)

L =

¯ QγµT AQ ¯ QγµT AQ

• O(1)

S

= ¯ Qt

• (¯

tQ)

O(8)

S

= ¯ QT At ¯ tT AQ

• t¯

tb¯ b and t¯ tt¯ t production at the LHC

σ4t σΛ−2

4t

σΛ−4

4t

σt¯

tb¯ b

σΛ−2

t¯ tb¯ b

σΛ−4

t¯ tb¯ b

σcut

t¯ tb¯ b

σcut

t¯ tb¯ b/σ4t

(fb) (fb) (fb) (pb) (pb) (pb) (pb) SM 4.86

• 7.2
• 0.348

71.6 O(1)

R

• 2.7

138

• O(1)

S

• 2.9

48

• <1.1

7.60 4.40 92 O(8)

S

• 0.49

11

• <0.2

1.28 0.76 71 O(1)

L

• 2.7

138

• <0.5

3.61 2.12 15.6 O(8)

L

• 0.91

15

• 0.49

0.77 0.42 28.2

if only tL is composite if both tL and tR are composite if only tR is composite cross sections at 14 TeV

ci = 4π Λ

assuming = 1 TeV

SLIDE 96

ttbb

• 200

400 600 800 1000 1.000 0.500 0.100 0.050 0.010 0.005 0.001 mbbGeV 1 Σ

• dΣ

d mbb

LHC s 14TeV

SM OS

1

OS

8

OL

1

OL

8

b b pair produced with invariant mass larger than in the SM

• nly relevant if tL is composite (constrained scenario)

SLIDE 97

L R L R L R + R L R L L R Lv

r

• H ¯

Qt H ¯ Qt

• δchg

S(T) R L L R R R

1-loop generation of the chromo-magnetic operator

Testing Ohg

SLIDE 98

tt + jets

• q

¯ q g t ¯ t g g g t ¯ t

[Flament’11]

2Mt¯

t

√s

SLIDE 99

.................

............ ............ Ohg = ¯ QLH

• σµνT atRGa

µν,

OHy = H†H

• H ¯

QL

• tR.

OH = ∂µ

• H†H
• ∂µ

H†H

• Constraints from higgs searches on top-philic new physics

δcHG ⇡ 0.03<chg 0.006cy.

cy = cH + v p 2mt < (cHy)

Degrande et al, to appear

OHG = 1 2H†HGa

µνGµν a .

120 140 160 180 200 0.4 0.2 0.0 0.2 mH cHG1TeV2

20 20 20 20 80 80 80 80

SLIDE 100

L L R R L R L L L R R (a) (b) (c) L L L (d)

m

H

=125 GeV m

H

=160 GeV

• 2
• 1

1 2

• 0.6
• 0.4
• 0.2

0.0 0.2 chgHTeVêLL2 cHGHTeVêLL2 cyHTeVêLL2 = 0 m

H

=125 GeV m

H

=160 GeV

• 2
• 1

1 2

• 0.6
• 0.4
• 0.2

0.0 0.2 chgHTeVêLL2 cHGHTeVêLL2 cyHTeVêLL2 =-5 m

H

=125 GeV m

H

=160 GeV

• 2
• 1

1 2

• 0.6
• 0.4
• 0.2

0.0 0.2 chgHTeVêLL2 cHGHTeVêLL2 cyHTeVêLL2 =+6

Using tth to constrain the chromomagnetic operator

• constraints from h production

constraints from tt production constraints from tth production

Degrande et al, to appear

SLIDE 101

Te top quark-baryogneti connection

SLIDE 102

Baryogenesis without B nor L nor CPT Possible if dark matter carries baryon number

Farrar-Zaharijas hep-ph/0406281 Agashe-Servant hep-ph/0411254

In a universe where baryon number is a good symmetry, Dark matter would store the overall negative baryonic charge which is missing in the visible quark sector

SLIDE 103

Mater Anti-mater asymmetry of t universe:

characterized in terms of the baryon to photon ratio

η ≡ nB − nB nγ

~ 6. 10-10

10 000 000 001 Matter The great annihilation between nucleons & anti-nucleons 10 000 000 000 Anti-matter 1 (us)

n + ¯ n → π + π → γ + γ + ...

Γ ∼ (mNT)3/2e−mN/T /m2

π ∼ H ∼ √g∗T 2/mP l

• ccurs when

corresponding to a freeze-out temperature TF ~ 20 MeV

Γ H Γ ∼ H Γ H nN s ≈ 7 × 10−20

109 times smaller than observed, and there are no antibaryons

• > need to invoke an initial asymmetry

In absence of an asymmetry:

SLIDE 104

Ωdm Ωb ∼ 5

Does this indicate a common dynamics?

ndm − ndm ∝ nb − nb

If then

Ωdm Ωb ∼ (ndm − ndm)mdm (nb − nb)mb ∼ C mdm mb

Similarly, Dark Matter may be asymmetric

QDM(nDM − nDM) = Qb(nb − nb)

two possibilities: 1) asymmetries in baryons and in DM generated simultaneously 2) a pre-existing asymmetry (either in DM or in baryons) is transferred between the two sectors conservation of global charge: if efficient annihilations:

Ωdm Ωb ∼ Qb Qdm mdm mb

typical expected mass ~ GeV

SLIDE 105

X

DM

b

• ut-of equilibrium and CP violating decay of X

sequesters the anti baryon number in the dark sector, thus leaving a baryon excess in the visible sector

Ωb ≈ 1 6Ωm

A unified explanation for DM and baryogenesis

QDM(nDM − nDM) = Qb(nb − nb)

If efficient annihilation between and , and and DM

b

DM

b

ρDM = mDMnDM ≈ 6ρb → mDM ≈ 6QDM Qb GeV

asymmetry between b and b is created via the

• ut-of-equilibrium and CP-violating decay :

GUT baryogenesis at the TeV scale !

turns out to be quite natural in warped GUT models...

Agashe-Servant-Tulin in progress

SLIDE 106

Agashe-Servant’04

Proton stability & Stable GUT partner in Warped GUTs Q

L

uc

R

dc

R

L

L

e

c

R

ν

c

R

⎧ ⎫ ⎭ ⎩ ⎪ ⎪ ⎪ ⎪ ⎪ ⎪

multiplet has B=1/3 DM is RH neutrino from 16 of SO(10)

stable under Z3 : Φ → Φ e2πi[B− α−α

3 ]

number of color indices Has enhanced couplings to TeV KK modes (such as Z’) and top quark

SO(10) IR UV

tR Higgs DM light SM fermions

bulk fermion with (-+) BC -> light!

warping

SLIDE 107

Z3 symmetry in the SM:

Φ → Φ e

2πi

• B− (α− ¯

α) 3

⇥

number of color indices

Agashe-Servant’04

any non-colored particle that carries baryon number will be charged under Z3 e.g warped/composite GUTs conserved in any theory where baryon number is a good symmetry

SLIDE 108

However, the search for heavy top partners is strongly motivated by models of Higgs compositeness, that will survive in the next few years

Summary 1

So far ATLAS and CMS papers related to searches for heavy b’, t’ ... remained mainly motivated by fourth generation The presence of light top partners constitutes the most visible manifestation of the composite Higgs scenario

SLIDE 109

Effective field theory approach to BSM: characterizes new physics in a model-independent way, useful to set bounds on non-resonant new physics

Summary II

2011 LHC data already rules out large region of parameter space Models of top compositeness can lead to zero signal at 7-8 TeV while non-zero signals (4 top production + top partners production) at 14 TeV New constraints on the 4-fermion and the chromomagnetic

• perators and more to come (looking forward to the

measurement of tt invariant mass distribution) complementarity between Higgs, tt and ttH production