Probing ZWW couplings through Z⁰→Wff′

We investigated the possibility of probing the ZWW couplings through the rare decay mode Z⁰→Wff′ of Z⁰. Neglecting masses of the fermions, we computed the combined polarization density matrix of Z and W as a function of the most general ZWW couplings. Integrations over phase space are carried out and the diagonal matrix elements are expressed as quadratic forms of the seven independent couplings. We found that several charge symmetrix polarization channels are particularly sensitive to the CP-violating coupling f₆, which is proportional to the weak magnetic quadrupole moment.