the pseudorapidity $\eta$ and the azimuthal angle $\phi$.

-   The opening angle between the electron and positron tracks is required to be limited by $5^0 < \theta_{e^+e^-} < 175^0$. This ensures elimination of possible cosmic ray backgrounds, and also ensures sufficient missing energy.

-   The missing invariant mass $M_{\rm miss}$ should satisfy the cut $|M_{\rm miss} - M_Z| > 10$ GeV. This important cut eliminates many SM backgrounds in which two final state neutrinos arise from a $Z$-decay.

= 9.0 cm=8.0cm =9.0 cm=8.0cm

Incorporating all these cuts into a Monte Carlo event generator, we obtain the distribution in missing invariant mass shown in Figure 2. It is clear from the figure that the missing invariant mass of the signal is much harder than that of the background. This is easy to understand if we realize that the missing mass is a measure of the energy of the emitted graviton. Now it is well-known that the higher the energy, the more strongly the graviton is coupled to matter and consequently the higher the production cross-section. Moreover, a higher energy leads to a higher density of states, and this further enhances the cross-section. In Figure 2, we have also shown the value 