230 likes | 242 Views
Non-standard Higgs Boson interactions and (inverse) implications for LHC. Daniel Phalen, Brooks Thomas, James Wells Michigan/MCTP, April 2006. Measured Sensitivities to Higgs mass. EWWG, 2005. Observables Compatible with SM. Many observables computed at LEP, SLC, and Tevatron
E N D
Non-standard Higgs Boson interactions and (inverse) implications for LHC Daniel Phalen, Brooks Thomas, James Wells Michigan/MCTP, April 2006
Measured Sensitivities to Higgs mass EWWG, 2005
Observables Compatible with SM Many observables computed at LEP, SLC, and Tevatron that tell us about compatibility.
Higgs mass limit Higgs boson mass upper limit (95% CL) from precision Electroweak is about 200 GeV. Lower limit from lack of direct signal at LEP 2 is about 115 GeV. LEPEWWG M.Peskin
Compatibility of New Physics It is reasonable to assume that new physics may have a light SM-like Higgs boson and extra stuff that mostly decouples from Precision EW analysis. Precision EW conspiracies are possible but we do not consider that here.
Small Higgs pheno deviations However, in most beyond the SM scenarios, The lightest Higgs is not exactly the SM Higgs. The deviations are nonzero but small. How do we characterize these deviations in the most model-independent fashion possible? How are they to be measured?
Supersymmetry Mass matrix of the CP-even scalars in {Hd,Hu} basis: Mass matrix rotated to get mass eigenstates {h,H}
Expansion about Small Deviations Loinaz, JW
Loop decays and SUSY Of course, we also know about SUSY particle Contributions to higgs decays to photons and gluons Top quark, W, and SUSY sparticles in the loop Top quarks, and squarks in the loop
Extra Dimensions: Radion Kinetic terms: Interactions with massive fermions and bosons: Interactions with gluons -- Tr(T) not equal to zero:
Small Higgs deviations Small kinetic mixing between radion and Higgs creates an eigenstate that is very close to the SM Higgs boson. Deviations characterized by
Model-Independence No such thing as true, complete model independence. More accurately labeled goal: study with “more Model independence” than generic MSSM or Generic extra dimensional scenario, etc. Multiply every Higgs interaction by a parameter.
Jt( ) J( ) Jt(gg) Jg(gg) Jt(Z) J-Functions: Decay Widths
J-Functions: Branching Ratios Different final states are of importance in different mass regions. Etc.
J functions ( sensitivities) for (ggh)B(h ) Jt Jb JW JZ JV J Jg JZ
Study Plans • Compare small expansion to full =(1+ ) result. • Catalog patterns in k for various models • Generalize effective theory NRO couplings to gauge invariant operators • Detail precision electroweak implications • Generalize analysis to exotic final states • Understand effective theory possibilities for low luminosity (10 fb-1) and high luminosity (0.1 - 1 ab-1) • Understand “basis set of observables” for each Higgs mass range that would enable determinations
Additional Remarks Emphasis here was on Feynman diagrams: Multiply all of them that involve Higgs boson by unknown k=1+k and determine from experiment. For small deviations, expansion about small is reasonable to gauge sensitivity in shifts in observables. (Systematic uncertainties make this borderline for low luminosity especially.) Good experimentation/measurement of other sectors helps. E.g., measurement of superpartner masses would give and g to enable check for consistency. Similar comment for heavy Higgs measurements of SUSY, or radion and KK states of X-dim. Comprehensive measurement approach, while parametrizing deviations from expectations in model-independent effective theory formalism should be helpful path.