egion of parameter space and one is then led to consider heavy scalars [@Albrecht:2007ii].

The situation is different for $\mu<0$ since the gluino contribution, which is the dominant contribution, already has the needed sign. In this case, the parameters need not be large in order to obtain a small threshold correction. This region of parameter space however was initially disfavored due to conflicts with flavor physics. When $\mu < 0$, the chargino contributions add constructively with the SM contributions to the $\mathcal{B}(B_s{\ensuremath{\rightarrow}}X_s\g)$ observable and hence yield enhanced values [@Baer:1997jq; @Baer:2000jj; @Carena:2000uj; @Auto:2003ys]. Additional complications also arise due to tensions with the $(g-2)_\mu$ observable in this regime, where the theoretical prediction is too small to match the experimental value. More recently, viable models with $\mu<0$ have been constructed but they typically have squark masses greater than 1 TeV [@Badziak:2013eda; @Ajaib:2014ana; @Anandakrishnan:2013cwa].

Fitting the bottom quark mass and satisfying current experimental constraints from flavor physics has therefore pushed Yukawa unified models into the territory of heavy scalars. Other models may of course be constructed that evade such restrictions, but the absence of the detection of any new physics at the LHC generically requires one to consider heavy scalar masses. The current limits on the colored superpartner masses are already approaching the TeV range [@ATLAS-SUSY; @CMS-SUSY]. As we transition into the TeV region of the SUSY parameter space, a re-evaluation of the approximations of SUSY threshold corrections to the bottom quark is warranted. This is especially important in the era of precision physics since the approximation is often invoked in studies of bottom quark mass and couplings.

In order to understand the size and behavior of the threshold corrections to the bottom quark, we survey a large part of the parameter space of interest and choose to scan over the parameters of the pMS