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Local Discrete Symmetries From Superstring Derived Models
| Content Provider | Semantic Scholar |
|---|---|
| Author | Faraggi, Alon E. |
| Copyright Year | 1996 |
| Abstract | Discrete and global symmetries play an essential role in many extensions of the Standard Model, for example, to preserve the proton lifetime, to prevent avor changing neutral currents, etc. An important question is how can such symmetries survive in a theory of quantum gravity, like superstring theory. In a speci c string model I illustrate how local discrete symmetries may arise in string models and play an important role in preventing fast proton decay and avor changing neutral currents. The local discrete symmetry arises due to the breaking of the non{Abelian gauge symmetries by Wilson lines in the superstring models and forbids, for example dimension ve operators which mediate rapid proton decay, to all orders of nonrenormalizable terms. In the context of models of uni cation of the gauge and gravitational interactions, it is precisely this type of local discrete symmetries that must be found in order to insure that a given model is not in con ict with experimental observations. E-mail address: faraggi@phys.u .edu Discrete and global symmetries play a crucial role in many extensions of the Standard Model. Imposing such symmetries is in general necessary to insure agreement with various experimental observations. One example is the proton lifetime in the context of supersymmetric and superstring theories [1, 2, 3]. Supersymmetric theories give rise to dimension four and ve operators which may result in rapid proton decay. Forbidding such operators requires that we impose some discrete or global symmetry on the spectrum of speci c models. Another example is the avor changing neutral currents in supersymmetric models which requires the avor degeneracy of the soft breaking scalar masses. For example, in models of low{energy dynamical SUSY breaking, the supersymmetry breaking is mediated to the observable sector by a messenger sector which consists of down{like quarks and electroweak doublets. The SUSY breaking is mediated to the observable sector by the gauge interactions of the Standard Model, which are avor blind. These messenger sector states would in general have avor dependent interactions with the Standard Model quarks which will induce avor changing neutral currents. It is therefore imperative that we impose a discrete symmetry which prevents the undesired interactions. In the framework of point quantum eld theories, it is of course simple to impose such discrete and global symmetries. However, it is well known that quantum gravity e ects are, in general, expected to violate global and discrete symmetries [4]. The only exception to this expectation are local discrete symmetries [5]. Local discrete symmetries are discrete symmetries which arise from broken gauge symmetry. However, it is still di cult to envision how such symmetries will arise from a fundamental theory of gravity. The problem is best illustrated in the context of the realistic free fermionic superstring models [6, 7, 8]. In these models the cubic level and higher order terms in the superpotential are obtained by evaluating the correlators between the vertex operators [9, 10] AN hV f 1 V f 2 V b 3 V b 4 V b Ni; (1) where V f i (V b i ) are the fermionic (scalar) components of the vertex operators. The non{vanishing terms are obtained by applying the rules of Ref. [10]. |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | http://arxiv.org/pdf/hep-ph/9611219v1.pdf |
| Alternate Webpage(s) | http://cds.cern.ch/record/314076/files/9611219.pdf |
| Alternate Webpage(s) | http://arxiv.org/pdf/hep-ph/9611219v2.pdf |
| Language | English |
| Access Restriction | Open |
| Subject Keyword | ARID1A wt Allele C string handling Cations Cubic function Degeneracy (graph theory) Dietary Nickel Dynamical system Email Imperative programming Interaction Naruto Shippuden: Clash of Ninja Revolution 3 Observable Perturbation theory Protons Rule (guideline) Vertex |
| Content Type | Text |
| Resource Type | Article |
