On a $Z^{prime}$ signature at next high energy electron-positron colliders

The associated production of a $Z^{prime}$ and a final hard photon in high energy electron-positron colliders is studied. It is shown that the hard photon spectrum contains useful information on the $Z^{prime}$ properties. This remark suggests that, if a new neutral gauge boson exists for $M_{Z^{prime}} < sqrt{s}$, it will not be necessary to make a new energy run at the $Z^{prime}$ mass in order to get most of its properties.