Same-Side Flavor-Tagging in $B_s$ Decays at D0

A same-side tagging method is applied to determine the $b/\bar{b}$-quark flavor of $B_s$-mesons at the time of production in proton-antiproton collisions. The performance of the method is determined using Monte Carlo techniques. The verification of the method is performed on real $B^\pm \to J/\psi K^\pm$ events and Monte Carlo samples. The same-side tagging method is combined with opposite-side tagging to take into account all the available information about initial $B_s$ meson flavor. The analysis serves as a foundation for application of the same-side tagging method to $B_s$-meson data samples.