New Physics and novel Higgs signals

We review some of the results of our recent work dealing with the novel type of Higgs signals that arise when one considers extensions of the standard model. We discuss first possible deviations on the Higgs couplings due to heavy particles, in the context of the MSSM and with large extra-dimensions. Then, we present several models where it is possible to induce flavor violating Higgs couplings, and probe them at future hadron colliders through the LFV Higgs decay h-> tau mu or with rare top decays.Comment: Talk given at the X Mexican School of Particles and Fields, Playa del Carmen, Mexico, 200

Top-Quark FCNC Decay t->cgg in Topcolor-assisted Technicolor Model

The topcolor-assisted technicolor (TC2) model predicts several pseudo-scalars called top-pions and at loop level they can induce the FCNC top quark decay t->cgg which is extremely suppressed in the Standard Model (SM). We find that in the allowed parameter space the TC2 model can greatly enhance such a FCNC decay and push the branching ratio up to 10^{-3}, which is much larger than the predictions in the SM (10^{-9}) and in the minimal supersymmetric model (10^{-4}). We also compare the result with the two-body FCNC decay t-> cg and find that the branching ratio of t-> cgg is slightly larger than t-> cg. Such enhanced FCNC top quark decays may serve as a good probe of TC2 model at the future top quark factory.Comment: 11 pages, 4 figure

Search for the Lepton Flavour Violating Higgs decay H --> tau mu at Hadron Colliders

We study the prospects to detect at hadron colliders the Lepton Flavour Violating Higgs decay H --> tau mu, which can reach substantial branching fractions in several extensions of the SM. Among them, the generic two higgs doublet model can be taken as a representative case where B.R.(H --> tau mu) can reach values of order 10^-1-10^-2. Bounds on the LFV factor kappa_{tau mu} of order 0.8-1.7 can be derived at 95% c.l. at Tevatron Run-2 with 4 fb^-1 for m_H = 110-150 GeV.Comment: 3 pages, 1 figure, uses RevTeX4. Contribution to Snowmass 200