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The superworlds of SU(5) and SU(5) x U(1): a critical assessment and overview

We present an overview of the simplest supergravity models which enforce radiative breaking of the electroweak symmetry, namely the minimal $SU(5)$ supergravity model and the class of string-inspired/derived supergravity models based on the flipped $SU(5)\times U(1)$ structure supplemented by a mini...

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Detalles Bibliográficos
Autores principales: López, J L, Nanopoulos, Dimitri V, Zichichi, Antonino
Lenguaje:eng
Publicado: 1993
Materias:
Acceso en línea:http://cds.cern.ch/record/251098
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author López, J L
Nanopoulos, Dimitri V
Zichichi, Antonino
author_facet López, J L
Nanopoulos, Dimitri V
Zichichi, Antonino
author_sort López, J L
collection CERN
description We present an overview of the simplest supergravity models which enforce radiative breaking of the electroweak symmetry, namely the minimal $SU(5)$ supergravity model and the class of string-inspired/derived supergravity models based on the flipped $SU(5)\times U(1)$ structure supplemented by a minimal set of additional matter representations such that unification occurs at the string scale ($\sim10^{18}\GeV$). These models can be fully parametrized in terms of the top-quark mass, the ratio $\tan\beta=v_2/v_1$, and three supersymmetry breaking parameters ($m_{1/2},m_0,A$). The latter are chosen in the minimal $SU(5)$ model such that the stringent constraints from proton decay and cosmology are satisfied. In the flipped $SU(5)$ case we consider two string-inspired supersymmetry breaking scenaria: $SU(N,1)$ no-scale supergravity and a dilaton-induced supersymmetry breaking scenario. Both imply universal soft supersymmetry breaking parameters: $m_0=A=0$ and $m_0=\coeff{1}{\sqrt{3}}m_{1/2}, A=-m_{1/2}$ respectively. We present a comparative study of the sparticle and Higgs spectra of both flipped $SU(5)$ models and the minimal $SU(5)$ model and conclude that all can be partially probed at the Tevatron and LEPII (and the flipped models at HERA too). In both flipped $SU(5)$ cases there is a more constrained version which allows to determine $\tan\beta$ in terms of $m_t,m_{\tilde g}$ and which leads to much sharper and readily accessible experimental predictions. We also discuss the prospects for indirect experimental detection: a non-trivial fraction of the parameter space of the flipped $SU(5)$ models is in conflict with the present experimental allowed range for the $b\to s\gamma$ rare decay mode, and the one-loop electroweak radiative corrections imply the 90\% CL upper bound
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spelling cern-2510982019-09-30T06:29:59Zhttp://cds.cern.ch/record/251098engLópez, J LNanopoulos, Dimitri VZichichi, AntoninoThe superworlds of SU(5) and SU(5) x U(1): a critical assessment and overviewParticle Physics - PhenomenologyWe present an overview of the simplest supergravity models which enforce radiative breaking of the electroweak symmetry, namely the minimal $SU(5)$ supergravity model and the class of string-inspired/derived supergravity models based on the flipped $SU(5)\times U(1)$ structure supplemented by a minimal set of additional matter representations such that unification occurs at the string scale ($\sim10^{18}\GeV$). These models can be fully parametrized in terms of the top-quark mass, the ratio $\tan\beta=v_2/v_1$, and three supersymmetry breaking parameters ($m_{1/2},m_0,A$). The latter are chosen in the minimal $SU(5)$ model such that the stringent constraints from proton decay and cosmology are satisfied. In the flipped $SU(5)$ case we consider two string-inspired supersymmetry breaking scenaria: $SU(N,1)$ no-scale supergravity and a dilaton-induced supersymmetry breaking scenario. Both imply universal soft supersymmetry breaking parameters: $m_0=A=0$ and $m_0=\coeff{1}{\sqrt{3}}m_{1/2}, A=-m_{1/2}$ respectively. We present a comparative study of the sparticle and Higgs spectra of both flipped $SU(5)$ models and the minimal $SU(5)$ model and conclude that all can be partially probed at the Tevatron and LEPII (and the flipped models at HERA too). In both flipped $SU(5)$ cases there is a more constrained version which allows to determine $\tan\beta$ in terms of $m_t,m_{\tilde g}$ and which leads to much sharper and readily accessible experimental predictions. We also discuss the prospects for indirect experimental detection: a non-trivial fraction of the parameter space of the flipped $SU(5)$ models is in conflict with the present experimental allowed range for the $b\to s\gamma$ rare decay mode, and the one-loop electroweak radiative corrections imply the 90\% CL upper boundhep-ph/9307211ACT-1993-13CERN-TH-6934-93CTP-TAMU-93-34oai:cds.cern.ch:2510981993
spellingShingle Particle Physics - Phenomenology
López, J L
Nanopoulos, Dimitri V
Zichichi, Antonino
The superworlds of SU(5) and SU(5) x U(1): a critical assessment and overview
title The superworlds of SU(5) and SU(5) x U(1): a critical assessment and overview
title_full The superworlds of SU(5) and SU(5) x U(1): a critical assessment and overview
title_fullStr The superworlds of SU(5) and SU(5) x U(1): a critical assessment and overview
title_full_unstemmed The superworlds of SU(5) and SU(5) x U(1): a critical assessment and overview
title_short The superworlds of SU(5) and SU(5) x U(1): a critical assessment and overview
title_sort superworlds of su(5) and su(5) x u(1): a critical assessment and overview
topic Particle Physics - Phenomenology
url http://cds.cern.ch/record/251098
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