B_{s,d}--> mu^+ mu^- in technicolor model with scalars

Rare decays B_{s,d}–>mu^+ mu^- are evaluated in technicolor model with scalars. R_b is revisited to constrain the model parameter space. It is found that restriction on f/f’ arising from R_b which was not considered in previous studies requires f/f’ no larger than 1.9 at 95% confidence level, implying no significantly enhancement for Br(B_{s,d}–>mu^+\mu^-) from neutral scalars in the model. However, the branching ratio of B_s–> mu^+ mu^- can still be enhanced by a factor of 5 relative to the standard model prediction. With the value of f/f’ about 1.9, an upgraded Tevatron with an integrated luminosity 20fb^-1 will be sensitive to enhancement of B_s–>mu^+ mu^- in this model provided that neutral scalar mass m_sigma is below 580 GeV.