Flavor-changing Higgs-boson transitions

The flavor-changing Higgs-boson vertex $q_i{q}_{j}H$ where $H$ is the Higgs boson and $q_i$,$q_j$ are quarks with flavors $i$,$j$ $\left(i\ne j\right)$, respectively, is calculated in the standard model for all values of external and internal masses. It is then used to determine the $b^{\prime }\to \mathrm{bH}$ decay width, where $b^{\prime }$ is a charge -⅓ fourth-family quark. We find that for a range of masses the mode $b^{\prime }\to \mathrm{bH}$ can be very important and even be the dominant decay of the $b^{\prime }$. If the fourth family exists, this decay may provide a way to detect the still elusive Higgs boson.