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Boaz Keren-Zur

Publications and source records attributed to Boaz Keren-Zur.

14 recordsLinked to original sources
arXiv2015

The local Callan-Symanzik equation: structure and applications

The local Callan-Symanzik equation describes the response of a quantum field theory to local scale transformations in the presence of background sources. The consistency conditions associated with this anomalous equation imply non-trivial relations among the $β$-function, the anomalous dimensions of composite operators and the short distance singularities of correlators. In this paper we discuss various aspects of the local Callan-Symanzik equation and present new results regarding the structure of its anomaly. We then use the equation to systematically write the n-point correlators involving the trace of the energy-momentum tensor. We use the latter result to give a fully detailed proof that the UV and IR asymptotics in a neighbourhood of a 4D CFT must also correspond to CFTs. We also clarify the relation between the matrix entering the gradient flow formula for the $β$-function and a manifestly positive metric in coupling space associated with matrix elements of the trace of the energy momentum tensor.

hep-th↗
arXiv2015

Superspace formulation of the local RG equation

We present the superspace formulation of the local RG equation, a framework for the study of supersymmetric RG flows in which the constraints of holomorphy and R-symmetry are manifest. We derive the consistency conditions associated with super-Weyl symmetry off-criticality and initiate the study of their implications. As examples, we derive an expression for the a-function, and present an analog of the a-maximization equation, which is valid off-criticality. We also apply this machinery to the study of conformal manifolds and give a simple proof that the metric on such manifolds is Kahler.

hep-th↗
arXiv2014

The local RG equation and chiral anomalies

We generalize the local renormalization group (RG) equation to theories with chiral anomalies. We find that a new anomaly is required by the Wess-Zumino consistency conditions. Taking into account the new anomaly, the trace of the energy momentum tensor is expressed in terms of the covariant flavor currents, instead of the consistent ones. This result is used to show that a flavor rotation induced by the RG flow can be eliminated by a choice of scheme even in the presence of chiral anomalies. As part of a general discussion of chiral anomalies in the presence of background sources, we also derive non-renormalization theorems. Finally, we introduce the $θ$ parameter as a source, and derive constraints on a perturbative running of this parameter.

hep-th↗
arXiv2013

The dilaton Wess-Zumino action in higher dimensions

We present a general formula for the Wess-Zumino action associated with the Weyl anomaly, given in a curved background for any even number of dimensions. The result is obtained by considering a finite Weyl transformation of counterterms in dimensional regularization.

hep-th↗
arXiv2012

On Partial Compositeness and the CP asymmetry in charm decays

Recently, the LHCb and CDF collaborations reported the measure of an unexpectedly large direct CP asymmetry in D meson decays. In this paper we ask if new physics associated with Partial Compositeness could plausibly explain this result. We find that Composite Higgs models with mass scale around 10 TeV can account for it, while marginally satisfying all other flavor constraints in the quark sector. The minimal framework is however inadequate in the lepton sector due to the strong constraint from μ to e γ. This tension can be efficiently alleviated by realizing Partial Compositeness within Supersymmetry. The resulting models can saturate the CP asymmetry in D decays for superpartner masses close to the TeV scale and somewhat large A-terms. The supersymmetric realization of Partial Compositeness also offers a predictive and phenomenologically viable organizing principle for R-Parity violation, and may result in very distinctive signatures at hadron colliders. With or without Supersymmetry, the neutron EDM is expected to be around the present experimental sensitivity.

hep-ph↗
arXiv2012

Supersymmetric sound in fluids

We consider the hydrodynamics of supersymmetric fluids. Supersymmetry is broken spontaneously and the low energy spectrum includes a fermionic massless mode, the $\mathit{phonino}$. We use two complementary approaches to describe the system: First, we construct a generating functional from which we derive the equations of motion of the fluid and of the phonino propagating through the fluid. We write the form of the leading corrections in the derivative expansion, and show that the so called diffusion terms in the supercurrent are in fact not dissipative. Second, we use an effective field theory approach which utilizes a non-linear realization of supersymmetry to analyze the interactions between phoninos and phonons, and demonstrate the conservation of entropy in ideal fluids. We comment on possible phenomenological consequences for gravitino physics in the early universe.

hep-ph↗
arXiv2009

Dark Matter and Pseudo-flat Directions in Weakly Coupled SUSY Breaking Sectors

We consider candidates for dark matter in models of gauge mediated supersymmetry breaking, in which the supersymmetry breaking sector is weakly coupled and calculable. Such models typically contain classically flat directions, that receive one-loop masses of a few TeV. These pseudo-flat directions provide a new mechanism to account for the cold dark matter relic abundance. We discuss also the possibility of heavy gravitino dark matter in such models.

hep-ph↗
arXiv2009

Direct Mediation and a Visible Metastable Supersymmetry Breaking Sector

We analyze an R-symmetry breaking deformation of the ISS model for a direct mediation of supersymmetry breaking from a metastable vacuum. The model is weakly coupled and calculable. The LSP gravitino is light (m_{3/2}<16 eV) and the MSSM spectrum is natural with a light Higgs. The supersymmetry breaking sector, which is usually hidden, is observable (m~1 TeV) and may be a candidate for cold dark matter. We discuss its production and signature at LHC. We propose a UV completion of the model in terms of a duality cascade.

hep-ph↗
arXiv2008

The Quark Model and $b$ Baryons

The recent observation at the Tevatron of $Σ_b^{\pm}$ ($uub$ and $ddb$) baryons within 2 MeV of the predicted $Σ_b - Λ_b$ splitting and of $Ξ_b^-$ $(dsb)$ baryons at the Tevatron within a few MeV of predictions has provided strong confirmation for a theoretical approach based on modeling the color hyperfine interaction. The prediction of $M(Ξ^-_b) = 5790$ to 5800 MeV is reviewed and similar methods used to predict the masses of the excited states $Ξ_b^\prime$ and $Ξ_b^*$. The main source of uncertainty is the method used to estimate the mass difference $m_b - m_c$ from known hadrons. We verify that corrections due to the details of the interquark potential and to $Ξ_b$--$Ξ_b^\prime$ mixing are small. For S-wave $qqb$ states we predict $M(Ω_b) = 6052.1 \pm 5.6$ MeV, $M(Ω^*_b) = 6082.8 \pm 5.6$ MeV, and $M(Ξ_b^0) = 5786.7 \pm 3.0$ MeV. For states with one unit of orbital angular momentum between the $b$ quark and the two light quarks we predict $M(Λ_{b[1/2]}) = 5929 \pm 2$ MeV, $M(Λ_{b[3/2]}) = 5940 \pm 2$ MeV, $M(Ξ_{b[1/2]}) = 6106 \pm 4$ MeV, and $M(Ξ_{b[3/2]}) = 6115 \pm 4$ MeV. Results are compared with those of other recent approaches.

hep-ph↗
arXiv2007

Predictions for masses of bottom baryons

The recent observation of Sigma_b^{+-} (uub and ddb) and Xi_b^- (dsb) baryons at the Tevatron within 2 MeV of our theoretical predictions provides a strong motivation for applying the same theoretical approach, based on modeling the color hyperfine interaction, to predict the masses of other bottom baryons which might be observed in the foreseeable future. For S-wave qqb states we predict M(Omega_b) = 6052.1+-5.6 MeV, M(Omega^*_b) = 6082.8+-5.6 MeV, and M(Xi_b^0) = 5786.7 +- 3.0 MeV. For states with one unit of orbital angular momentum between the b quark and the two light quarks we predict M(Lambda_{b[1/2]}) = 5929+-2 MeV, M(Lambda_{b[3/2]}) = 5940+-2 MeV, M(Xi_{b[1/2]}) = 6106+-4 MeV, and M(Xi_{b[3/2]}) = 6115+-4 MeV.

hep-ph↗
arXiv2007

Predictions for masses of Xi_b baryons

The recent observation by CDF of Sigma_b^{+-} (uub and ddb) baryons within 2 MeV of the predicted Sigma_b - Lambda_b splitting has provided strong confirmation for the theoretical approach based on modeling the color hyperfine interaction. We now apply this approach to predict the masses of the Xi_b family of baryons with quark content usb and dsb - the ground state Xi_b at 5790 to 5800 MeV, and the excited states Xi_b^' and Xi_b^*. The main source of uncertainty is the method used to estimate the mass difference m_b - m_c from known hadrons. We verify that corrections due to the details of the interquark potential and to Xi_b-Xi_b^' mixing are small.

hep-ph↗
arXiv2007

Testing confining potentials through meson/baryon hyperfine splitting ratio

In this paper we discuss a quantity that can be derived from the hadronic spectrum - the ratio between the color hyperfine splitting of a K meson and that of a Sigma baryon. It will be shown that within the constituent quark model this ratio depends only on the ratio of contact probabilities within the hadrons. We compute this ratio assuming several phenomenological potential models, and show that the best agreement with data is obtained from the Cornell potential - Coulomb + linear. Thus the analysis of color hyperfine interactions corroborat es the preference for the Cornell potential based on quarkonium spectra.

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