Chargino mass and R(b) anomaly

We reexamine 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 tan beta in the region of the parameter space with M(2) approximate to \mu\ and mu < 0 a shift in R(b) remains significant (delta R(b) approximate to 0.002) even for the lighter chargino as heavy as 90-100GeV. It is an interesting mixture of the up-higgsino and gaugino. The role of various phenomenological constraints is discussed in analytic form and importance of small but nonnegligible left-right mixing in the stop sector is emphasized in this context. Since the available data do not rule out the large tan beta scenario, this option for enhancement of R(b) is also reviewed.