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arXiv · hep-ph/9603310

Chargino Mass and $R_b$ Anomaly

P. H Chankowski·S. Pokorski
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Abstract

We re-examine the possible magnitude of the supersymmetric contribution to $R_b$ with imposed all available phenomenological constraints and demanding good quality of the global fit to the precision electroweak data. For low $\tanβ$ we find a new region of the parameter space, with $M_2\approx |μ|$ and $μ<0$ where $R_b$ remains large, $\sim0.2180$ even for the lighter chargino as heavy as $90-100$ GeV. It is an interesting mixture of the up-higgsino and gaugino. The rôle of various phenomenological constraints is discussed in analitic form and importance of small but non-negligible left-right mixing in the stop sector is emphasized in this context. The large $\tanβ$ option for enhancement of $R_b$ is also reviewed. The available data do not rule out this scenario.

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P. H Chankowski, S. Pokorski. 1996-03-14. Chargino Mass and $R_b$ Anomaly. https://doi.org/10.1016/0550-3213(96)00317-3

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