Two-loop contributions to the [Beta] - [|Beta] mixing amplitude
It is known that the Standard Model, being a spontaneously broken gauge theory, violates the decoupling theorem. In practice, this means that amplitudes for low-energy processes grow without limit as the mass of fermions or scalars is made large. As a result of the recent determination of a lower...
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| Language: | English |
| Published: |
2008
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| Online Access: | http://hdl.handle.net/2429/3198 |
| Summary: | It is known that the Standard Model, being a spontaneously broken gauge theory, violates
the decoupling theorem. In practice, this means that amplitudes for low-energy processes
grow without limit as the mass of fermions or scalars is made large. As a result of the
recent determination of a lower bound of 90 GeV on the mass of the top quark and the
general expectation of a large mass for the Higgs boson, this effect could lead to large
higher order corrections to the observables of the theory. In this spirit, we calculate the
two-loop corrections to the [Beta] - [|Beta] mixing amplitude in the two limits of a very large
top quark mass or a very large Higgs mass. Analytical expressions are obtained for the
leading terms. The results are found to be much smaller than what one would naively
expect. |
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