Flavor and Scalar Signalsof an Extended Color Sector
R. Sekhar ChivukulaMichigan State University- Extended Color Dynamics- A Top-Coloron Model- Flavor Symmetries and Constraints- Scalars: Same Sign Top Signature- Flavor Independent Constraints- Conclusions
KMI, Nagoya University

March 5-7, 2014

Extended Color Dynamics
New colored gauge bosons
Classic Axigluon: P.H. Frampton and S.L. Glashow, Phys. Lett. B 190, 157 (1987).
Topgluon: C.T. Hill, Phys. Lett. B 266, 419 (1991).
Flavor-universal Coloron: R.S. Chivukula, A.G. Cohen, & E.H. Simmons, Phys. Lett. B 380, 92 (1996).
Chiral Color with gL ≠ gR: M.V. Martynov and A.D. Smirnov, Mod. Phys. Lett. A 24, 1897 (2009).
New Axigluon: P.H. Frampton, J. Shu, and K. Wang, Phys. Lett. B 683, 294 (2010).

Other color-octet states: (cf. “partial compositeness”)
KK gluon: H. Davoudiasl, J.L. Hewett, and T.G. Rizzo, Phys. Rev. D63, 075004 (2001)
B. Lillie, L. Randall, and L.-T. Wang, JHEP 0709, 074 (2007).

Techni-rho: E. Farhi and L. Susskind, Physics Reports 74, 277 (1981).

Recent catalog of colored states:
Color sextets, colored scalars, low-scale scale string resonances...
T. Han, I. Lewis, Z. Liu, JHEP 1012, 085 (2010).

Gauge Sector

Coloron Models: Gauge SectoruSU(3)1SU(3)2

h1h2

✓2u
SU(3)1 x SU(3)2 color sector with M =42

unbroken subgroup: SU(3)1+2 = SU(3)QCD

h21
h1 h2

h1 =gluon state:

gscos ✓h2 =gssin ✓AAGA=cos✓A+sin✓Aµ1µ2µcouples to:coloron state:h1 h2h22◆CµA =µgS JG⌘ gS (J1µ + J2µ )Asin ✓ AA+cos✓A1µ2µu
MC = p2µµµcouples to: gS JC ⌘ gS ( J1 tan ✓ + J2 cot ✓)low-energy current-current interaction:

L2F F =qh21 + h22gS2 µ
J JC µ
2MC2 CFermionsColoron Models: Quark Charges
SU(3)2µgS JG⌘ gS (J1µ + J2µ )h2gS JCµ ⌘ gS ( J1µ tan ✓ + J2µ cot ✓)u
SU(3)1h1

low-energy current-current interaction:

L2F F =gS2 µJC JC µ22MCDepending on how quarks transform under SU(3)1 x SU(3)2
the presence of colorons may impact• LHC dijet mass distribution (or angular distribution)• kinematic distributions of tt or bb final states• asymmetry in top-quark production: AtFB• FCNC processes: K K̄, DD̄, B B̄ mixing, b ! s• precision EW observables: delta-rho, Rb

Patterns of Quark Charges
SU(3)1qR
tR,bR

SU(3)2model

pheno.

(t,b)L qL tR,bR qR

colorondijet

new axigluon

dijet, AtFB, FCNC

topgluon

dijet, tt, bb,FCNC, Rb...

classic axigluon

dijet, AtFB(t,b)L qL tR,bR(t,b)L qL

qL(t,b)LqL tR,bR(t,b)LqL
tR,bRqR(t,b)LqR(t,b)L qL

qL tR,bR qR

qRtR,bR

qR
qR

tR,bR

(t,b)L(No spectators required)q = u,d,c,s

A FlavorfulTop-Coloron Model
R.S.C., Elizabeth Simmons, N. Vignaroli
PRD 87 (2013) 075002

Flavorful Top-Coloron Modelparticles
3rd generation
quarkslight quarks
vector quarks
light scalar
heavy scalarSU(3)1

SU(3)2

SU(2)W(t,b)L312tR,bR

3

1

1(u,d)L (c,s)L1

32uR,dR cR,sR

131QL,QR

31211233*1𝞿
ΦNext to minimal flavor symmetry:

Generational Mixing
SU(3)1 x SU(3)2 x SU(2)W(1,1,2)(3, 3*,1)

<𝞿>

<Φ>

tR, bR

QL(3,1,1)(3,1,2)X

QR(u,d)L(c,s)L(3,1,2)(1,3,2)Mixing to third generation occurs indirectly,through mixing with vector quarks.

Generational Mixing
Light Generations

Weak Mixing

Cabbibo Matrix, C , and{{{{{{Third GenerationVector Quarks
d = O(1)↵1 = O( 3 )↵2 = O( 2 )Constraints fromFlavor Physics
R.S.C., Elizabeth Simmons, N. Vignaroli
PRD 87 (2013) 075002

FCNC in Top-Coloron Model• Mixing among ordinary and heavy vector quarks also
leads to flavor-changing b-quark decays: b ! s• Coloron exchange yields KK, DD, and BB mixing‣ quark charges under strong gauge groups are
non-universal‣ the top and bottom mass eigenstate quarks are
admixtures of ordinary and heavy vector gaugeeigenstate quarks

Constraints: b→sΥ

0.004

Mixing with righthanded electroweak
doubletsenhances contributions
to b→sγ

Re@l'b D

0.002

0.000-0.002-0.004-0.4-0.20.0

Re@l't D

0.20.4sL

bLbLbb Mixing
Constraints:
B-BbarssssLLLCbL

LbL

sL

bL

sL

LsL

CsL
sL

(a)

CbL
bL

(b)

bL

bL

sL

bL

L

sL

sL

sL

bL

(c)

bL

Flavor-changing Effects
fromColoron
Exchange:bL
bL
sL
sL coupling strengths
interplay between
mixing andFlavor Limits on Top-Coloron Model
MC HTeVL54Allowed...depends on α2l2

KK mixing
may excludel2 ë 2

32

KK mixing
may exclude

LHC dijetsexcludel2 ë 3BB mixing and1b!s0

KK mixing
certainlyexcludes

exclude12

3

45Cotw
Θ

R.S. Chivukula, EHS, N. Vignaroli (2013)

Scalar Bosons
R.S.C., Elizabeth Simmons, N. Vignaroli
PRD 88 (2013) 034006
Bogdan Dobrescu and Yang Bai
JHEP 1107 (2011) 100

Colored Scalars and Their Potential_Most general renormalizable (3,3) potential:

For an appropriate range of parameters:vevsinglet fields

eaten by colorons{Color Octet Scalars
Quark couplings fixed from above!

Octet Scalar Productions @fbD

GH Double Production
LHC-14
LHC-8

105
LHC-7
Tevatron

104

1000

100

10200

400

600

800

1000

MGH HGeVL

Octet Scalar Decay
Dijets:GHGH

μ related to singlet
pseudoscalar massc̄L tR + t̄R cL :

GHGH

µGHg

GHg

g

µGHg

Top + Charm Often Very Large!
4000
0.2

0.4

0.1

0.5
0.3

3500

0.6

0.7
0.8

3000
0.9

M∆I HGeVL

2500

2000

__BR to t+c or c+t

1500

1000

pseudo-scalarmass

500

200

400600

MGH HGeVL

800

1000

octet mass
Octet pair production can lead tosame-sign tops (dileptons)!

Experimental Constraints
5000

4000

HGH Æ ggL
di - jets

CMSM∆I HGeVL

ATLAS
3000

2000

HGH Æ tcL

SSD + jets

1000

CMS

200

250

MGH HGeVL

Singlet mass dependence frombehavior of BRs

300

350

400

450

References: CMS PAS SUS-12-029
ATLAS arXiv:1210.4826
CMS arXiv:1302.0531

FlavorUniversalConstraints
On Scalars
R.S.C., Arsham Farzinnia, Jing Ren,and Elizabeth Simmons
PRD 88 (2013) 075020 and in pressScalar Potential: Higgs and Mixing
Scalar potential includes Higgs boson as well:V( , )⇢h6✓†vh22

◆2+m✓

†vh22

◆✓⇥
Tr†

⇤

vs2
2

“Higgs portal” coupling: mixing between electroweak andcolor sectors

h = cos h0

sin0R

◆

Precision Electroweak Constraints
0.00
150 GeVS - T contour
at 95% C.L.

3000
sin c = 0.5-0.01 900 GeV

sin c = 0.2-0.02

Excluded by S - T
at 95% C.L.

2500

230 GeV
3000 GeV-0.03
450 GeV

-0.04

2000

ms HGeVL

T

Excludedregion1500
1000-0.05
0.00

0.01

0.02

0.03

0.04

0.05

500

Sh,±R

0.0

0.2

0.4

0.6

0.8

sin c

W ,Z

S-T contours from Gfitter, arXiv:1209.2716

1.0

New States Contribute to Higgs Production!
Colorons

Scalars

SpectatorFermionsATLAS Higgs Observation

Moriond EW 2013, LP2013
ATLAS-CONF-2013-034,012,013

CMS Higgs Observation

Moriond EW 2013, LP2013
CMS-PAS-HIG-13-001,2
CMS-PAS-HIG-12-045

Constraints from Higgs Observation
Coloron and colored scalar contributions to production...

h ! I I allowed
Note scale for vs!

CMS-PAS-HIG-13-005
ATLAS-CONF-2013-034
Yao, Moriond EW 2013

Illustration of Combined Results
u=1000 GeV
mGH= 500 GeV

u=5000 GeV
mGH= 2000 GeV
Unitarity

Unitarity

allowedHiggs
production

S-T
S-T

Higgs
production

allowedIllustrates interplay of different constraints ...
and of direct and indirect bounds

Heavy Singlet Boson
LHC Reach in σ*BR/(σ*BR)SM Higgs
7+8 TeVm Hgg Æ s Æ VVL

1current

00
3,
Vefb

14 T

0.1

projected

00
03,
eV-1

fb

14 T

0.01

200-1

400

600
ms HGeVL

800

1000

CMS-PAS-HIG-13-002/3ATLAS-CONF-2013-013/030

LHC Singlet Boson Reach
Projection with 300 fb-1 @ 14 TeV
Discovery Region

Excluded by current
heavy Higgs search

125 GeV Higgs production exclusion(one spectator fermion)

Illustrates that direct limits/searches will dominate!

Conclusions

Conclusions
Many models predict extended strong interactions
Is this extended dynamics flavor-universal or not?
• Introduced a flavorful top-coloron model• Constraints from FCNCs favor NMFV.
• Same-sign tops, and therefore dileptons, an interesting
signature for new colored scalars.
Additional effects of extended strong interactions?
• Color symmetry breaking sector can mix with EWSB
• Constraints on Higgs mixing and from observed
properties of Higgs boson• Discovery potential for heavy states at 14 TeV