String unification, spaghetti diagrams and infra-red fixed points
نویسندگان
چکیده
منابع مشابه
String Unification , Spaghetti Diagrams and Infra - Red Fixed Points
We consider a scenario in which the minimal supersymmetric standard model (MSSM) is valid up to an energy scale of ∼ 10 16 GeV, but that above this scale the theory is supplemented by extra vector-like representations of the gauge group, plus a gauged U(1) X family symmetry. In our approach the extra heavy matter above the scale ∼ 10 16 GeV is used in two different ways: (1) to allow (two-loop)...
متن کامل3 v 3 9 J ul 1 99 7 RAL 97 - 007 SHEP 97 - 01 hep - ph / 9703293 String Unification , Spaghetti Diagrams and Infra - Red Fixed Points
The minimal supersymmetric standard model (MSSM), is perhaps the leading candidate for new physics beyond the standard model, but it encounters difficulties with string gauge unification and in addition does not shed any light on the question of fermion masses. We consider a scenario in which the MSSM is valid up to an energy scale of ∼ 10 16 GeV, but that above this scale the theory is supplem...
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In order to achieve gauge unification at the string scale M X ∼ 5 × 10 17 GeV in the minimal supersymmetric standard model (MSSM) it is necessary to add extra gauge non-singlet representations at an intermediate scale M I < M X , leading to a class of models which we refer to as MSSM+X models. We perform a detailed analysis of a large class of MSSM+X models and find that the number of (3,1) rep...
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The Standard Model (SM) is a great success in describing the strong and electroweak interactions based on an underlying gauge principle, but one of its main weaknesses is that the masses of the matter particles, the quarks and leptons, are free parameters of the theory. This weakness persists in the Minimal Supersymmetric Standard Model (MSSM). The fermions mass problem in the MSSM arises from ...
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Gauged supergravities (in four and five dimensions) with eight supercharges and with vector supermultiplets have a unique ultra-violet (UV) fixed point on a given physical domain M of the space of the scalar fields. We show that in these models the infra-red (IR) fixed points are located on the boundary of M, where the space-time metric becomes singular. e-mail: [email protected] e-mai...
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ژورنال
عنوان ژورنال: Nuclear Physics B
سال: 1997
ISSN: 0550-3213
DOI: 10.1016/s0550-3213(97)00571-3