Oram Gedalia

Ultravisible warped model from flavor triviality and improved naturalness

A warped extra-dimensional model, where the standard model Yukawa hierarchy is set by UV physics, is shown to have a sweet spot of parameters with improved experimental visibility and possibly naturalness. Upon marginalizing over all the model parameters, a Kaluza-Klein scale of 2.1 TeV can be obtained at 2{sigma} (95.4% C.L.) without conflicting with electroweak precision measurements. Fitting all relevant parameters simultaneously can relax this bound to 1.7 TeV. In this bulk version of the Rattazzi-Zaffaroni shining model, flavor violation is also highly suppressed, yielding a bound of 2.4 TeV. Nontrivial flavor physics at the LHC in the form of flavor gauge bosons is predicted. The model is also characterized by a depletion of the third-generation couplings--as predicted by the general minimal flavor violation framework--which can be tested via flavor precision measurements. In particular, sizable CP violation in {Delta}B=2 transitions can be obtained, and there is a natural region where B{sub s} mixing is predicted to be larger than B{sub d} mixing, as favored by recent Tevatron data. Unlike other proposals, the new contributions are not linked to Higgs or any scalar exchange processes.

Combining direct & indirect kaon CP violation to constrain the warped KK scale

Abstract The Randall–Sundrum (RS) framework has a built in protection against flavour violation, but still generically suffers from little CP problems. The most stringent bound on flavour violation is due to ϵ K , which is inversely proportional to the fundamental Yukawa scale. Hence the RS ϵ K problem can be ameliorated by effectively increasing the Yukawa scale with a bulk Higgs, as was recently observed in arXiv:0810.1016 . We point out that incorporating the constraint from ϵ ′ / ϵ K , which is proportional to the Yukawa scale, raises the lower bound on the KK scale compared to previous analyses. The bound is conservatively estimated to be 5.5 TeV, choosing the most favorable Higgs profile, and 7.5 TeV for the profile which roughly reproduces the two site case. Relaxing this bound might require some form of RS flavour alignment. As a by-product of our analysis, we also provide the leading order flavour structure of the theory with a bulk Higgs.

Lessons from Recent Measurements of D0 - anti-D0 Mixing

An impressive progress in measurements of the D 0 - D 0 mixing parameters has been made in recent years. We explore the implications of these measurements to models of new physics, especially in view of recent upper bounds on the amount of CP violation. We update the constraints on nonrenormalizable four-quark operators. We show that the experiments are close to probing minimally flavor violating models with large tanβ. The data challenge models with a scale of order TeV where the flavor violation in the down sector is suppressed by alignment and, in particular, certain classes of supersymmetric models and of warped extra dimension models.

Extraordinary phenomenology from warped flavor triviality

Abstract Anarchic warped extra dimensional models provide a solution to the hierarchy problem. They can also account for the observed flavor hierarchies, but only at the expense of little hierarchy and CP problems, which naturally require a Kaluza–Klein (KK) scale beyond the LHC reach. We have recently shown that when flavor issues are decoupled, and assumed to be solved by UV physics, the frameworkʼs parameter space greatly opens. Given the possibility of a lower KK scale and composite light quarks, this class of flavor triviality models enjoys a rather exceptional phenomenology, which is the focus of this Letter. We also revisit the anarchic RS EDM problem, which requires m KK ≳ 12 TeV , and show that it is solved within flavor triviality models. Interestingly, our framework can induce a sizable differential t t ¯ forward–backward asymmetry, and leads to an excess of massive boosted di-jet events, which may be linked to the recent findings of the CDF Collaboration. This feature may be observed by looking at the corresponding planar flow distribution, which is presented here. Finally we point out that the celebrated standard model preference towards a light Higgs is significantly reduced within our framework.

Implications of the CDF tt¯ forward–backward asymmetry for boosted top physics

Abstract New physics at a high scale Λ can affect top-related observables at O ( 1 / Λ 2 ) via the interference of effective four quark operators with the SM amplitude. The ( u ¯ γ μ γ 5 T a u ) ( t ¯ γ μ γ 5 T a t ) operator modifies the large M t t ¯ forward–backward asymmetry, and can account for the recent CDF measurement. The ( u ¯ γ μ T a u ) ( t ¯ γ μ T a t ) operator modifies the differential cross section, but cannot enhance the cross section of ultra-massive boosted jets by more than 60%. The hint for a larger enhancement from a recent CDF measurement may not persist future experimental improvements, or may be a QCD effect that is not accounted for by leading order and matched Monte Carlo tools or naive factorization. If it comes from new physics, it may stem from new light states or an O ( 1 / Λ 4 ) new physics effect.

Implications of the CDF

The CDF collaboration has recently reported a large deviation from the standard model of the

t\bar{t}

t\bar{t}

forward-backward asymmetry for hard top physics

forward-backward asymmetry in the high invariant mass region. We interpret this measurement as coming from new physics at a heavy scale Λ, and perform a model-independent analysis up to

On the universality of CP violation in ΔF=1 processes

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Spin determination via third generation cascade decays

. A simple formalism to test and constrain models of new physics is provided. We find that a large asymmetry cannot be accommodated by heavy new physics that does not interfere with the standard model. We show that a smoking gun test for the heavy new physics hypothesis is a significant deviation from the standard model prediction for the