Theory Department
Renormalization of the Standard Model and its Supersymmetric
Extension
Elisabeth Kraus
In phenomenological calculations in the standard model and its
extensions it is necessary to include radiative correction to the
predictions. The comparison between theoretical predictions and
experimental precision data permits tests and comparisons of models in
their quantum structure.
Computing radiative corrections faces one with a technical problem:
the corresponding loop diagrams are divergent and have to be
renormalized. Supersymmetric models generally feature a better
divergence structure and this is the most important reason why they are
considered as important candidates for physics beyond the standard model
although they lack experimental evidence.
While the explicit renormalization of divergent loop graphs in the
standard model can be technically handled quite easy, since one can in
principle use the gauge invariant scheme of dimensional regularization,
the renormalization of supersymmetric extensions requires fundamental
understanding of all defining symmetries of the model.
In the framework of algebraic renormalization,
the symmetry conditions can be rigorously deduced to all orders and make
it possible to do an abstract renormalization of supersymmetric models.
We apply this method to the minimal supersymmetric extension of the
standard model.
In collaboration with the research group of
Prof.
Hollik (Karlsruhe University) we use
the symmetry conditions in explicit calculations to obtain consistent
results for theoretical predictions beyond the classical approximation.
18. August 2000
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