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Дата индексирования: Mon Oct 1 22:41:03 2012
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Menu 1. Menu 2 Choice of the model and work with it Choice of the model and work with it Contents

Menu 1.

This menu contains a list of available models. It offers you an option to select a model of elementary particle interaction for subsequent work.

There are four models built in CompHEP: quantum electrodynamics, the model of electroweak four-fermion interaction, and two versions of the Standard Model. The QED model is included as an example of realization of the simplest particle interaction scheme in CompHEP. The four-fermion interaction model gives an example of realization of the four-fermion interaction in the CompHEP  notations. The Standard Model is presented in two gauges: the unitary one and the t'Hooft-Feynman one. We recommend to choose the latter for calculations because the ultra-violet cancellations between diagrams caused by gauge invariance are absent in this case. See the discussion in Section Ghost fields and the squared diagram technique for the t'Hooft-Feynman gauge . The Standard Model in the unitary gauge is used for verification of gauge invariance.

The bottom menu function provides you with a possibility to include a new model into the CompHEP  list. New model is created as a copy of one of existing models. On the next menu level you can change this copy. If you choose the "New Model" menu function you will be prompted for a new model name and a template source. CompHEP  adds the underscore symbol '_' in front of the name of new model. It serves to distinguish user's models from the built-in ones. To choose a template the list of existing models appears.