1. New Strong Interactions @ LHC
Rogerio Rosenfeld
Instituto de Física Teórica
UNESP

2. Based on: Les Houches working group on WW scattering
Delgado, Grojean, Maina, RR
Color octet scalar production
Zerwekh, Dib, RR

3. Main goal of LHC: find EWSB mechanism
SM Higgs sector suffers from naturalness and
hierarchy problem: why mH << L?
Usual solutions:
SUSY (radiative EWSB)
(theory valid up to L~ Planck)
New strong interactions at the TeV scale
(SM Higgs is an effective theory valid up to L~ TeV)

4. VL VL scattering probes EWSB sector
New ideas have motivated many
new models for EWSB
4D strongly coupled theory dual to weakly
coupled 5D warped theory (4D resonances  KK excitations)
Higgs as a PNGB
Gauge-Higgs unification in extra-dimensions
Higgsless models in extra-dimensions
VL VL scattering probes EWSB sector

5. Attempt to classify new models
Inflation of models (Greg’s talk)
Heavy resonances are hallmark of strong
interactions
They may or may not be within LHC reach
Scalars and vector resonances have different
phenomenology

6. Attempt to classify models
No (light) vector
resonances
Light vector
resonances
OBS: not all resonances are related to EWSB
Chiral lagrangians
(non-linear realization)
Low Scale Technicolor
Higgsless
No (light) Higgs
Holographic TC
Higgs
profile
BESS
Standard Model
Warped/Composite
LDBESS
Light Higgs
Strongly Interacting Light
Higgs
Little Higgs
Gauge-Higgs unification
Twin Higgs

7. General comments Heavy resonances can mix with gauge bosons
Models can be determined by (R: new resonance):
mass eigenvalues MR and MV
couplings gRVV and ghVV
Interactions with VL is enhanced:
gRVLVL = gRVV (MR/MV)2
Couplings of R to fermions arise from mixing

8. General comments EW precision tests 
needs custodial symmetry to keep T small
needs large masses/small couplings of
resonances or extra discrete symmetry to
keep S small

9. Resonance production @ LHC
2 production processes:
Drell-Yan V
g sinq V
= vector resonance that mixes with SM gauge bosons
or scalar resonances with coupling to light fermions

10. Resonance production @ LHC
Vector boson fusion VL VL VL VL

11. Comparison between DY and VBF
(back of the envelope)
Effective W approximation + narrow width approximation:
model dependent
model independent ~ 10-5
If resonance couples to mass (like Higgs), VBF dominates

12. Examples of resonance production @ LHC
Bagger et al (1995)
ET/EWA

13. Examples of resonance production @ LHC
Agashe et al (2007)
Warped EW model

14. Examples of resonance production @ LHC
He et al (2007)
Higgsless model

15. Examples of resonance production @ LHC
Hirn, Martin and Sanz (2007)
W’1,2 in Holographic TC DY
VBF

16. New Strong Interactions @ LHC
Many new different models in the market
Phenomenology of different models are similar
(e.g., new W’ and Z’ resonances)
Phenomenology of different models determined
by few parameters (resonances masses and
couplings). Idea: construct a “generic model”
and implement it in MadGraph (only scalar + vector resonances).
Challenge to VBF: NLO (Zeppenfeld et al).

17. Color octet scalars @ LHC
Some models predict color octet scalars:
5th component of gluon KK (Burdman, Dobrescu and Ponton 06)
one-family TC
extended scalar sector(Manohar and Wise 06, Gresham and Wise 07,
Dobrescu et al 07, Gerbush et al 07)
Large QCD pair production cross section
Decays mainly into bb,tt; large backgrounds

18. Analogue of p  gg (ABJ anomaly)
Color octet LHC
Worthwhile to look at rare decay modes
(info about model) Zerwekh, Dib and RR (preliminary) g P8 g
Analogue of p  gg (ABJ anomaly)

19. Color octet scalars @ LHC
Production processes of pairs of colored octets
in WTC models (Zerwekh and RR 2001)

20. Simulations: look for pp g+3j (CompHEP)
Example with MP = 320 GeV (below tt threshold)
Mr = 640 GeV (insensitive) , FQ = 80 GeV (insensitive)
Backgrounds: irreducible pp g+3j and
pp 4j with prob jet-photon misid. (MadGraph)
energy smearing
cuts

21. 10 fb-1
background
signal

22. Conclusions Many BSM models with new strong interactions
Possibly a “generic model” can describe many
of the proposed models (3-site moose model, LDBESS)
Can be tested at the LHC:
resonance production (Drell-Yan vs. VBF)
New color-octet scalars can be copiously produced at
the LHC and rare decays can give info about
underlying model.
Eagerly waiting the LHC