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 d emanding good quality of the global fit to the precision electroweak d ata. For low tan beta in the region of the parameter space with M(2) a pproximate to \mu\ and mu < 0 a shift in R(b) remains significant (del ta R(b) approximate to 0.002) even for the lighter chargino as heavy a s 90-100GeV. It is an interesting mixture of the up-higgsino and gaugi no. The role of various phenomenological constraints is discussed in a nalytic form and importance of small but nonnegligible left-right mixi ng in the stop sector is emphasized in this context. Since the availab le data do not rule out the large tan beta scenario, this option for e nhancement of R(b) is also reviewed.