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New Strong Interactions @ LHC

New Strong Interactions @ LHC. Rogerio Rosenfeld Instituto de Física Teórica UNESP. Based on:. Les Houches working group on WW scattering Delgado, Grojean, Maina, RR Color octet scalar production Zerwekh, Dib, RR. Main goal of LHC: find EWSB mechanism.

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New Strong Interactions @ LHC

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  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. 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 Low Scale Technicolor Chiral lagrangians (non-linear realization) 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. Color octet scalars @ 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. 10-3 jet-photon misid. (MadGraph) cuts energy smearing

  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

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