Related papers: $R_b$ in supergravity models
We propose a simple gauged U(1)$_{B-L}$ extension of the minimal supersymmetric Standard Model (MSSM), where R-parity is conserved as usual in the MSSM. The global $B-L$ (baryon number minus lepton number) symmetry in the MSSM is gauged and…
The recent measurement by CDF M(Sigma_b)-M(Lambda_b)=192 MeV is in striking agreement with our theoretical prediction M(Sigma_b)-M(Lambda_b) = 194 MeV. In addition, the measured splitting M(Sigma_b*)-M(Sigma_b) = 21 MeV agrees well with the…
We consider the one-loop corrections to the $Z b \bar b$ vertex in a $CP$-conserving left--right model (LRM), $viz$. a model with gauge group $SU(2)_L \times SU(2)_R \times U(1)$. We allow the gauge coupling constants of $SU(2)_L$ and…
We consider the supersymmetry (SUSY) transformations in the chiral Lagrangian for $N = 1$ supergravity (SUGRA) with the complex tetrad following the method used in the usual $N = 1$ SUGRA, and present the explicit form of the SUSY…
We propose a simple gauge extension of the minimal supersymmetric standard model (MSSM), where the fine tuning in the Higgs mass parameters is highly reduced. The Higgs boson is insensitive to high energies because of supersymmetry and also…
Model-independent bounds on the Hubble constant $H_0$ are important to shed light on cosmological tensions. We work out a model-independent analysis based on the sum rule, which is applied to late- and early-time data catalogs to determine…
We discuss the dimensional reduction of fermionic modes in a recently found class of consistent truncations of type IIB supergravity compactified on squashed five-dimensional Sasaki-Einstein manifolds. We derive the lower dimensional…
In left-right symmetric models, large contributions to the decay amplitude $b \rightarrow s+ \gamma$ can arise from the mixing of the $W_L$ and $W_R$ gauge bosons as well as from the charged Higgs boson. These amplitudes are enhanced by the…
We focus on a simple, natural and predictive T model of inflation in Supergravity employing as inflaton the Higgs field which leads to the spontaneous breaking of a U(1)_(B-L) symmetry at the SUSY GUT scale. We use a renormalizable…
We study Higgs boson couplings in the large-$\lambda$ version of the Next-to-Minimal Supersymmetric Standard Model, known as $\lambda$-SUSY. We find that the predicted deviations from the Standard Model (SM) in these couplings are inversely…
We consider the radiative decay b \to s \gamma in a supersymmetric extension of the standard model of particle interactions, where the $b$-quark mass is entirely radiative in origin. This is accomplished by the presence of nonholomorphic…
We have studied the SUSY scale dependence of supersymmetric radiative corrections to bottom quark mass on the branching ratio of $B_s^0 \to \mu^+\mu^-$ and its impact on the cMSSM parameter space. The supersymmetric radiative corrections to…
The recent developments in theory and experiment related to the anomalous magnetic moment of the muon are applied to supersymmetry. We follow a very cautious course, demanding that the supersymmetric contributions fit within five standard…
Gamma-ray bursts (GRBs) are luminous enough to be detectable up to redshift $z\sim 10$. They are often proposed as complementary tools to type-Ia supernovae (SNe Ia) in tracing the Hubble diagram of the Universe. The distance calibrations…
It is challenging to explain the tentative 125 GeV Higgs signal in the Minimal Supersymmetric Standard Model (MSSM) without introducing excessive fine-tuning, and this motivates the study of non-minimal implementations of low energy…
We explore the one-loop electroweak radiative corrections in the context of the traditional minimal $SU(5)$ and the string-inspired $SU(5)\times U(1)$ supergravity models by calculating explicitly vacuum-polarization and vertex-correction…
We give a formulation of linearized 11D supergravity in 4D, $N=1$ superspace keeping all eleven bosonic coordinates. The fields are fluctuations around $\mathbf M=\mathbf R^{4|4}\times Y$, where $Y$ is a background Riemannian 7-manifold…
A model is presented that could lead to an interesting extension of the Standard Model. Like a supersymmetric gauge theory, the model is holomorphic and invariant to local superspace gauge transformations. However, the model is not…
Polarized $\Lambda_b \to \Lambda \gamma$ decays at the Z pole are shown to be well suited for probing a large variety of New Physics effects. A new observable is proposed, the angular asymmetry between the $\Lambda_b$ spin and photon…
We present a calculation of the branching ratio $\brbsg$ in two well motivated supersymmetric models: the minimal $SU(5)$ and the no-scale flipped $SU(5)$ supergravity models. We find that the improved CLEO upper bound…