Model independent constraints among theWtb,Zbb¯, andZtt¯couplings

Using an effective Lagrangian approach, we perform a model-independent analysis of the interactions among electroweak gauge bosons and the third generation quarks, i.e. the $Wtb$, $Zt\overline{t}$, and $Zb\overline{b}$ couplings. After one imposes the known experimental constraint on the $Z{b}_L{b}_L$ coupling, we show that the electroweak $SU(2{)}_L\times U(1{)}_Y$ symmetry of the standard model specifies the pattern of deviations of the $Z{t}_L{t}_L$ and $W{t}_L{b}_L$ couplings, independent of underlying new physics scenarios. We study implications of the predicted pattern with data on the single top quark and $Zt\overline{t}$ associated production processes at the Large Hadron Collider. Such an analysis could in principle allow for a determination of the $Wtb$ coupling without prior knowledge of $|V_{tb}|$, which is otherwise difficult to achieve.