Related papers: $R_b$ in supersymmetric models
We evaluate the SUSY and top threshold effects in the context of the MSSM and the string derived model based on SU(4)$\times$SU(2)$_L\times$SU(2)$_R$. In both cases we run the two loop RGEs and determine the lower bounds of the…
This is the written version of a talk given by S.K. at the $10^{th}$ International Conference on High Energy and Astroparticle, Constantine, Algeria. We briefly review the Standard Model (SM) and the major evidences and main direction of…
After reviewing the theoretical, phenomenological and experimental motivations for supersymmetric extensions of the Standard Model, we recall that supersymmetric relics from the Big Bang are expected in models that conserve R parity. We…
The structure of gauged R supergravity Lagrangians is reviewed, and we consider models with a hidden sector plus light fields of the MSSM. A simple potential for the hidden sector is presented which has a global minimum with zero…
The experimental measurement of $B(b \to s\gamma)$ imposes important constraints on the charged Higgs boson mass in the MSSM. If squarks are in the few TeV range, the charged Higgs boson mass in the MSSM must satisfy $m_{H^{\pm}} \gsim 440$…
The generic supersymmetric standard model is a model built from a supersymmetrized standard model field spectrum the gauge symmetries only. The popular minimal supersymmetric standard model differs from the generic version in having…
Electroweak precision measurements can provide indirect information about the possible scale of supersymmetry already at the present level of accuracy. We update the present-day sensitivities of precision data using the new experimental…
A simple relativistic model of heavy-light mesons is applied to the rare decay B -> K* gamma in the standard model. We find Gamma(B -> K* gamma)/Gamma(b -> s gamma)=(17 \pm 4)% and BR(B -> K* gamma)=(4.8 \pm 1.9) \times 10^{-5}(V_cb/.04)^2.…
The minimal supersymmetric extension of the Standard Model (SM) is a well motivated scenario for physics beyond the SM, which allows a perturbative description of the theory up to scales of the order of the Grand Unification scale, where…
I summarize a part of the work done with Bamert, Burgess, London and Nardi (hep-ph/9602438) in which we find simplified expressions for the possible one-loop contributions to the $R_b$ parameter from new virtual particles, including…
We demonstrate the efficacy of symbolic regression (SR) to probe models of particle physics Beyond the Standard Model (BSM), by considering the so-called Constrained Minimal Supersymmetric Standard Model (CMSSM). Like many incarnations of…
We evaluate one-loop contributions to the C and P conserving $WW\gamma, WWZ$ form factors in the Minimal Supersymmetric Standard Model (MSSM), and in a more constrained Supergravity Grand Unified Theory (SUGRA-GUT). A systematic search of…
We derive sum rules for the sparticle masses in different models of supersymmetry breaking. This includes the gravity mediated models (SUGRA models) as well as models in which supersymmetry breaking terms are induced by super-Weyl anomaly…
We propose a new realization of softly broken supersymmetric theories as theories defined on stochastic superspace. At the classical level, the supersymmetry breaking is parameterized in terms of a single (in general complex) mass…
We evaluate the impact of radiative corrections in the ratios $\Gamma[B\to M \mu^+\mu^-]/\Gamma[B\to M e^+e^-]$ when the meson $M$ is a $K$ or a $K^*$. Employing the cuts on $m^2_{\ell\ell}$ and the reconstructed $B$-meson mass presently…
The radiative decay Z2-> Z1 gamma proceeds at the one-loop level in the MSSM. It can be the dominant decay mode for the second lightest neutralino Z2 in certain regions of parameter space of supersymmetric models, where either a dynamical…
Introducing an R-symmetry to models of high scale supersymmetry (SUSY) can have interesting consequences, and we focus on two aspects. If Majorana masses are forbidden by an R-symmetry and the main source of electroweak gaugino masses are…
The origin of R-parity in supersymmetric models can be explained if \BL is part of the gauge group. We discuss the mass spectrum of the minimal $U(1)_Y \times U(1)_{B-L}$ model based on a GUT implementation using CMSSM-like boundary…
We revisit minimal supersymmetric SU(5) grand unification (GUT) models in which the soft supersymmetry-breaking parameters of the minimal supersymmetric Standard Model (MSSM) are universal at some input scale, $M_{in}$, above the…
We demonstrate that the lightest chargino can be lighter than the lightest neutralino in supersymmetric models with Dirac gaugino masses as well as within a curious parameter region of the MSSM. Given also a light gravitino, such as from…