Jay Hubisz

The Flavor of a little Higgs with T-parity

We analyze flavor constraints in the littlest Higgs model with T-parity. In particular, we focus on neutral meson mixing in the K, B, and D systems due to one loop contributions from T-parity odd fermions and gauge bosons. We calculate the short distance contributions to mixing for a general choice of T-odd fermion Yukawa couplings. We find that for a generic choice of textures, a TeV scale GIM suppression is necessary to avoid large contributions. If order one mixing angles are allowed in the extended flavor structure, the mass spectrum is severely constrained, and must be degenerate at the 1-5% level. However, there are still regions of parameter space where only a loose degeneracy is necessary to avoid constraints. We also consider the B(s) system, and identify a scenario in which the mixing can be significantly enhanced beyond the standard model prediction while still satisfying bounds on the other mixing observables. We present both analytical and numerical results as functions of the T-odd fermion mass eigenvalues.

Composite Higgs Sketch

A bstractThe couplings of a composite Higgs to the standard model fields can deviate substantially from the standard model values. In this case perturbative unitarity might break down before the scale of compositeness, Λ, is reached, which would suggest that additional composites should lie well below Λ. In this paper we account for the presence of an additional spin 1 custodial triplet ρ±,0. We examine the implications of requiring perturbative unitarity up to the scale Λ and find that one has to be close to saturating certain unitarity sum rules involving the Higgs and ρ couplings. Given these restrictions on the parameter space we investigate the main phenomenological consequences of the ρ’s. We find that they can substantially enhance the h → γγ rate at the LHC even with a reduced Higgs coupling to gauge bosons. The main existing LHC bounds arise from di-boson searches, especially in the experimentally clean channel ρ± → W±Z → 3l + ν. We find that a large range of interesting parameter space with 700 GeV ≾ mρ ≾ 2 TeV is currently experimentally viable.

A Naturally Light Dilaton and a Small Cosmological Constant

We present a non-supersymmetric theory with a naturally light dilaton. It is based on a 5D holographic description of a conformal theory perturbed by a close-to-marginal operator of dimension

Discovering a Higgs boson decaying to four jets in supersymmetric cascade decays

4-\epsilon

Goldstone Fermion Dark Matter

4-ϵ which develops a condensate. As long as the dimension of the perturbing operator remains very close to marginal (even for large couplings) a stable minimum at hierarchically small scales is achieved, where the dilaton mass squared is suppressed by

Odd decays from even anomalies: Gauge mediation signatures without supersymmetry

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