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Related papers: New Precision Electroweak Tests of SU(5) x U(1) Su…

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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.…

High Energy Physics - Phenomenology · Physics 2009-10-22 J. Lopez , D. V. Nanopoulos , G. Park , H. Pois , K. Yuan

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,…

High Energy Physics - Phenomenology · Physics 2009-10-30 Gye T. Park , Kang Young Lee

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…

High Energy Physics - Phenomenology · Physics 2009-11-05 Jihn E. Kim , Gye T. Park

We have performed a systematic analysis to compute the one-loop electroweak corrections to the Z->b b-bar vertex in terms of $\epsilon_b$ and $R_b$ in the context of the minimal $SU(5)$ and no-scale $SU(5)\times U(1)$ supergravity models.…

High Energy Physics - Phenomenology · Physics 2009-12-30 Jihn E. Kim , Gye T. Park

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…

High Energy Physics - Phenomenology · Physics 2009-09-25 J. Lopez , D. Nanopoulos , G. Park , X. Wang , A. Zichichi

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…

High Energy Physics - Phenomenology · Physics 2009-08-25 J. Lopez , D. Nanopoulos , G. Park , A. Zichichi

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…

High Energy Physics - Phenomenology · Physics 2007-05-23 J. Lopez , D. Nanopoulos , G. Park , X. Wang , A. Zichichi

We elaborate on a recently suggested effective Lagrangian for charged-current and neutral-current electroweak interactions which in comparison with the standard electroweak theory contains three free parameters $\Delta x, \Delta y$,…

High Energy Physics - Phenomenology · Physics 2009-10-28 S. Dittmaier , D. Schildknecht , K. Kolodziej , M. Kuroda

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…

High Energy Physics - Phenomenology · Physics 2015-06-25 Gye T. Park , T. K. Kuo

A new framework to study electroweak physics at one-loop level in general ${\rm SU(2)_L \times U(1)_Y}$ theories is introduced. It separates the 1-loop corrections into two pieces: process specific ones from vertex and box contributions and…

High Energy Physics - Phenomenology · Physics 2008-02-03 K. Hagiwara , S. Matsumoto , C. S. Kim

We discuss supersymmetric contributions to the electroweak precision measurements in the Minimal Supersymmetric Standard Model for two cases: the quark-lepton universality violation $\delta_{q\ell}$ in charged currents and the ratio…

High Energy Physics - Phenomenology · Physics 2009-10-28 Youichi Yamada , Kaoru Hagiwara , Seiji Matsumoto

We propose a string-derived model based on the gauge group $SU(5)\times U(1)$ which satisfies the stringent constraints from no-scale supergravity, allows gauge coupling unification at the string scale, and entails previously unexplored…

High Energy Physics - Phenomenology · Physics 2016-09-01 J. Lopez , D. Nanopoulos , A. Zichichi

We review the empirical evidence for the validity of the Standard Electroweak Theory in nature. The experimental data are interpreted in terms of an effective Lagrangian for Z physics, allowing for potential sources of SU(2) violation and…

High Energy Physics - Phenomenology · Physics 2007-05-23 Dieter Schildknecht

We compute the leading corrections to the properties of W and Z bosons induced at the one-loop level in the SU(5)/SO(5) Littlest Higgs model with T parity, and perform a global fit to precision electroweak data to determine the constraints…

High Energy Physics - Phenomenology · Physics 2009-11-11 Jay Hubisz , Patrick Meade , Andrew Noble , Maxim Perelstein

The one-loop radiative correction in an ultraviolet (UV) complete electroweak (EW) model without a Higgs particle is calculated. The $\rho$ parameter determining the ratio of the charged to neutral currents is derived for the dominant top…

High Energy Physics - Phenomenology · Physics 2011-07-07 J. W. Moffat

A novel approach to study electroweak physics at one-loop level in generic ${\rm SU(2)_L \times U(1)_Y}$ theories is introduced. It separates the 1-loop corrections into two pieces: process specific ones from vertex and box contributions,…

High Energy Physics - Phenomenology · Physics 2008-11-26 K. Hagiwara , D. Haidt , C. S. Kim , S. Matsumoto

We calculate the leading electroweak corrections to the light neutral Higgs boson production via $q\bar q'\to WH$ at the Fermilab Tevatron in both the standard model and the minimal supersymmetric model, which arise from the top-quark and…

High Energy Physics - Phenomenology · Physics 2011-01-13 Qing Hong Cao , Chong Sheng Li , Shou Hua Zhu

Applying No-Scale Supergravity boundary conditions at a heavy unification scale to the Flipped $SU(5)$ grand unified theory with extra TeV-scale vector-like multiplets, $i.e.$ No-Scale ${\cal F}$-$SU(5)$, we express the $Z$-boson mass $M_Z$…

High Energy Physics - Phenomenology · Physics 2014-12-03 Tristan Leggett , Tianjun Li , James A. Maxin , Dimitri V. Nanopoulos , Joel W. Walker

The Standard Model global fit to precision data is excellent. The Minimal Supersymmetric Standard Model can also fit the data well, though not as well as the Standard Model. At best, supersymmetric contributions either decouple or only…

High Energy Physics - Phenomenology · Physics 2009-10-31 Jens Erler , Damien M. Pierce

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…

High Energy Physics - Phenomenology · Physics 2015-06-25 Gye T. Park
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