Signal production cross section times branching fraction for Z<sup>&prime;</sup><sub>SFM</sub>, &sigma;B<sub>SFM</sub> , divided by &sigma;B<sub>SSM</sub> (left) and acceptance times efficiency for Z<sup>&prime;</sup><sub>SFM</sub>, Avarepsilon<sub>SFM</sub>, divided by Avarepsilon<sub>SSM</sub> for the &tau;<sub>had</sub>&tau;<sub>had</sub> (middle left), &tau;<sub>&mu;</sub>&tau;<sub>had</sub> (middle right) and &tau;<sub>e</sub>&tau;<sub>had</sub> (right) channels, as a function of sin<sup>2</sup>&phi; and m<sub>Z<sup>&prime;</sup></sub>.