相关论文: $\epsilon_b$ Constraints on the Minimal $SU(5)$ an…
We explore the one-loop electroweak radiative corrections in $SU(5)\times U(1)$ supergravity via explicit calculation of vacuum-polarization and vertex-correction contributions to the $\epsilon_1$ and $\epsilon_b$ parameters.…
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…
In the light of the top quark discovered very recently by CDF, we investigate the possibility of narrowing down the allowed top quark masses by combining for the first time only two strongest constraints present in the no-scale $SU(5)\times…
We update the analysis of the precision electroweak tests in terms of 4 epsilon parameters, $\epsilon_{1,2,3,b}$, to obtain more accurate experimental values of them by taking into account the new LEP data released at the 28th ICHEP (1996,…
We explore the one-loop electroweak radiative corrections in the minimal $SU(5)$ and the no-scale flipped $SU(5)$ supergravity models via explicit calculation of vacuum polarization contributions to the $\epsilon_{1,2,3}$ parameters.…
We extend our previous work on the precision electroweak tests in the Sp(6)_L X U(1)_Y family model to include for the first time the important Z->b b-bar vertex corrections encoded in a new variable epsilon_b, utilizing all the latest LEP…
We consider a class of well motivated string-inspired flipped $SU(5)$ supergravity models which include four supersymmetry breaking scenarios: no-scale, strict no-scale, dilaton, and special dilaton, such that only three parameters are…
We compute the one-loop corrections to the $Z \to b\bar{b}$ vertex in the $U(1)_R$ symmetric minimal supersymmetric extension of the standard model. We find that the predicted value of $R_b$ is consistent with experiment if the mass of the…
We perform a detailed study of the constraints from $b\to s\gamma$ on a large class of supergravity models, including generic four-parameter supergravity models, the minimal $SU(5)$ supergravity model, and $SU(5)\times U(1)$ supergravity.…
We perform a combined analysis of two stringent constraints on the 2 Higgs doublet model, one coming from the recently announced CLEO II bound on $B(b \rightarrow s \gamma)$ and the other from the recent LEP data on $\epsilon_b$. We have…
We re-examine the phenomenological aspects of a recently proposed string-derived SU(5)$\times$U(1) one-parameter supergravity model, and explore the sensitivity of the model predictions to variations in the strong coupling and the string…
A previous study of supersymmetric models has indicated that they are unlikely to make a large contribution to R_b. We revisit this analysis, taking into account the improved lower limits on sparticle masses provided recently by LEP 2 and…
We present the first constraints on the parameter space of $SU(5)\times U(1)$ supergravity (in both no-scale and dilaton scenarios) which arise from the recently announced limits on trilepton searches at the Tevatron. The trilepton rate has…
Concentrating on the impact of the very recent top quark discovery, we perform a combined analysis of two strongest constraints on the 2 Higgs doublet model, one coming from the recent measurement by CLEO on the inclusive branching ratio of…
In the minimal supergravity model (mSUGRA), as the parameter $\tan\beta$ increases, the charged Higgs boson and light bottom squark masses decrease, which can potentially increase contributions from $tH^\pm$, $\tg\tb_j$ and $\tz_i\tb_j$…
Minimal $N=1$ supergravity with a radiatively broken electroweak symmetry group is studied in the light gluino scenario. Constraints from the $b\rightarrow s\gamma$ decay and from the masses of the light CP-even neutral Higgs $m_h$, the…
A series of predictions are worked out in order to put the minimal $SU(5)$ supergravity model under experimental test. Using the two-loop gauge coupling renormalization group equations, with the inclusion of supersymmetric threshold…
Recent advances in the QCD corrections to $b\to s\gamma$ decay in the MSSM include i.) evaluation of the relevant operators, Wilson coefficients and anomalous dimension matrix elements for the various MSSM effective theories valid at scales…
We compute the supersymmetric contribution to $R_{b}\equiv \Gamma (Z\to b{\bar b})/\Gamma (Z\to {\rm hadrons})$ in a variety of supersymmetric models. In the context of supergravity models with universal soft-supersymmetry-breaking and…
We study various aspects of $SU(5)\times U(1)$ supergravity as they relate to the experimental verification or falsification of this model. We consider two string-inspired, universal, one-parameter, no-scale soft-supersymmetry-breaking…