- Extended Color Dynamics - A Top-Coloron Model - Flavor - - PowerPoint PPT Presentation

• R. Sekhar Chivukula

Michigan State University KMI, Nagoya University March 5-7, 2014

• Extended Color Dynamics
• A Top-Coloron Model
• Flavor Symmetries and Constraints
• Scalars: Same Sign Top Signature
• Flavor Independent Constraints
• Conclusions

Flavor and Scalar Signals

• f an Extended Color Sector

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

u h1 h2

SU(3)1 SU(3)2

Coloron Models: Gauge Sector

SU(3)1 x SU(3)2 color sector with unbroken subgroup: SU(3)1+2 = SU(3)QCD

M 2 = u2 4 ✓ h2

1

−h1h2 −h1h2 h2

2

◆

h1 = gs cos θ

h2 = gs sin θ

CA

µ = − sin θ AA 1µ + cos θ AA 2µ

GA

µ = cos θ AA 1µ + sin θ AA 2µ

gluon state: coloron state:

MC = u √ 2 q h2

1 + h2 2

couples to: couples to:

gSJµ

G ≡ gS(Jµ 1 + Jµ 2 )

gSJµ

C ≡ gS(−Jµ 1 tan θ + Jµ 2 cot θ)

low-energy current-current interaction:

L2

F F = − g2 S

2M 2

C

Jµ

CJC µ

Fermions

u h1 h2

SU(3)1 SU(3)2

Coloron Models: Quark Charges

gSJµ

G ≡ gS(Jµ 1 + Jµ 2 )

gSJµ

C ≡ gS(−Jµ 1 tan θ + Jµ 2 cot θ)

low-energy current-current interaction:

L2

F F = − g2 S

2M 2

C

Jµ

CJC µ

Depending 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: mixing,
• precision EW observables: delta-rho, Rb

K ¯ K, D ¯ D, B ¯ B

b → sγ

Patterns of Quark Charges

SU(3)1 SU(3)2 model pheno. (t,b)L qL tR,bR qR

coloron dijet

qR (t,b)L qL tR,bR tR,bR (t,b)L qL qR qL (t,b)L tR,bR qR qL tR,bR (t,b)L qR

new axigluon dijet, AtFB, FCNC

qL qR (t,b)L tR,bR

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

tR,bR qR (t,b)L qL

classic axigluon dijet, AtFB

qL tR,bR qR (t,b)L

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

A Flavorful Top-Coloron Model

R.S.C., Elizabeth Simmons, N. Vignaroli PRD 87 (2013) 075002

Flavorful Top-Coloron Model

particle rticles SU(3)1 SU(3)2 SU(2)W 3rd generation quarks (t,b)L 3 1

2

3rd generation quarks tR,bR 3 1

1

light quarks (u,d)L (c,s)L 1 3

2

light quarks uR,dR cR,sR 1 3

1

vector quarks QL,QR 3 1

2

light scalar 𝟀 1 1

2

heavy scalar

Φ

3 3*

1

Next to minimal flavor symmetry:

Generational Mixing

1,2)

<Φ> <𝟀>

tR, bR QL QR (u,d)L (c,s)L X

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

Mixing to third generation occurs indirectly, through mixing with vector quarks.

Generational Mixing

1,2)

C

Weak Mixing ⇒ Cabbibo Matrix, , and

{ {

Light Generations { { Third Generation Vector Quarks { {

d = O(1) α1 = O(λ3) α2 = O(λ2)

Constraints from Flavor 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:

• 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 gauge eigenstate quarks

b → sγ

Constraints: b→sΥ

Mixing with right- handed electroweak doublets enhances contributions to b→sγ

• 0.4
• 0.2

0.0 0.2 0.4

• 0.004
• 0.002

0.000 0.002 0.004

Re@Λt

'D

Re@Λb

' D

Constraints: B-Bbar Mixing

bL bL bL bL sL sL sL sL sL sL bL bL bL sL bL sL sL bL

(a) (b) (c)

C C C

Flavor-changing Effects from Coloron Exchange: interplay between mixing and coupling strengths

Λ2 Λ2 ë 2 Λ2 ë 3 1 2 3 4 5 CotΩ 1 2 3 4 5 MC HTeVL

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

Flavor Limits on Top-Coloron Model

LHC dijets exclude BB mixing and exclude KK mixing certainly excludes Θ KK mixing may exclude KK mixing may exclude

Allowed...depends on α2

b → sγ

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: vev singlet fields

{

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

Octet Scalar Production

200 400 600 800 1000 MGH HGeVL 10 100 1000 104 105 s @fbD

GH Double Production

Tevatron LHC-7 LHC-8 LHC-14

Octet Scalar Decay

GH GH GH GH g g GH GH GH g g

µ µ

Dijets:

¯ cLtR + ¯ tRcL :

μ related to singlet pseudoscalar mass

Top + Charm Often Very Large!

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 200 400 600 800 1000 500 1000 1500 2000 2500 3000 3500 4000 MGH HGeVL M∆I HGeVL

BR to t+c or c+t Octet pair production can lead to same-sign tops (dileptons)! _ _

• ctet mass

pseudo-scalar mass

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

Experimental Constraints

HGH Æ tcL SSD + jets HGH Æ ggL di - jets

CMS ATLAS CMS

200 250 300 350 400 450 1000 2000 3000 4000 5000

MGH HGeVL M∆I HGeVL

Singlet mass dependence from behavior of BRs

Flavor- Universal Constraints On Scalars

R.S.C., Arsham Farzinnia, Jing Ren, and Elizabeth Simmons PRD 88 (2013) 075020 and in press

Scalar Potential: Higgs and Mixing

V (φ, Φ) ⊂ λh 6 ✓ φ†φ − v2

h

2 ◆2 + λm ✓ φ†φ − v2

h

2 ◆ ✓ Tr ⇥ Φ†Φ ⇤ − v2

s

2 ◆

Scalar potential includes Higgs boson as well: “Higgs portal” coupling: mixing between electroweak and color sectors

h = cos χ h0 − sin χ φ0R

S-T contours from Gfitter, arXiv:1209.2716

Precision Electroweak Constraints

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

0.0 0.2 0.4 0.6 0.8 1.0 500 1000 1500 2000 2500 3000 sin Χ ms HGeVL

sin c = 0.5 sin c = 0.2

Excluded region

S - T contour at 95% C.L. 150 GeV 900 GeV 230 GeV 3000 GeV 450 GeV

0.00 0.01 0.02 0.03 0.04 0.05

• 0.05
• 0.04
• 0.03
• 0.02
• 0.01

0.00 S T

W ±, Z

h, φR

New States Contribute to Higgs Production!

Colorons Scalars Spectator Fermions

ATLAS Higgs Observation

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

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

CMS Higgs Observation

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

Constraints from Higgs Observation

h → φIφI allowed

Coloron and colored scalar contributions to production...

Note scale for vs!

Illustration of Combined Results

u=1000 GeV mGH= 500 GeV u=5000 GeV mGH= 2000 GeV Illustrates interplay of different constraints ... and of direct and indirect bounds

allowed Unitarity S-T Higgs production allowed Unitarity Higgs production S-T

Heavy Singlet Boson

7+8 TeV 14 TeV, 300 fb-1 14 TeV, 3000 fb-1

200 400 600 800 1000 0.01 0.1 1 ms HGeVL m Hgg Æ s Æ VVL

LHC Reach in σ*BR/(σ*BR)SM Higgs

current projected

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

LHC Singlet Boson Reach

Projection with 300 fb-1 @ 14 TeV

125 GeV Higgs production exclusion Excluded by current heavy Higgs search Discovery Region

(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