Extending theSTUFormalism for Electroweak Oblique Corrections to the Case of Light New Physics
✍ Scribed by Sean Fleming; Ivan Maksymyk
- Publisher
- Elsevier Science
- Year
- 1996
- Tongue
- English
- Weight
- 525 KB
- Volume
- 251
- Category
- Article
- ISSN
- 0003-4916
No coin nor oath required. For personal study only.
✦ Synopsis
The STU formalism, which parametrizes oblique electroweak corrections due to heavy new physics, has recently been extended to the case of light new physics. In principle, this extended formalism, which involves the six parameters STUVWX, must be used if loop contributions to the oblique corrections entail light new particles with masses in the range tM Z or less. Applying classical equations of motion to manipulate the effective lagrangian, we present here a thorough introductory discussion of the STUVWX formalism, elucidating such subtleties as the connection between S&X and the star formalism of Kennedy and Lynn, the connection between S&X, and the = parameters of Altarelli and Barbieri, and the loss of definite symmetry properties which S and U undergo as the STU parameter set is extended to the case of light new physics. This paper provides a significantly more detailed, expanded, and pedagogic presentation than previous expositions of the STUVWX parameters. 1996 Academic Press, Inc.
1. Introduction
In the world of four-fermion precision electroweak measurements, the STU formalism of Peskin and Takeuchi [1] has become an industry standard'' for parametrizing so-called oblique'' corrections originating from beyond-the-Standard-Model physics. By ``oblique'' corrections, we mean those new physics effects which may be cast in the form of contributions to electroweak gauge-boson self-energies. Other formalisms designed to organize oblique corrections have been discussed in [2] [5].