decay simulations

Before finalizing the design, more detailed simulations of the detector capabilities were undertaken. In particular, the performance of the detector for specific physics modes was studied in detail. These processes described below reflect some of the important physics goals of CLEO III and were chosen in such a way as to test the performance of the detector for a wide range of physics. For each process, was simulated with one forced to decay in a particular fashion while the other decayed according to the branching ratios. Thus all track overlap, lost track, multiplicity, and combinatoric problems were present.

Presently CLEO II has a large program to reconstruct charged and neutral decays via the mode . In this analysis, two variables are plotted: the mass difference and the mass. After cutting on these variables, a beam energy constraint is applied to determine the candidate mass: . In Fig. we show the mass difference for 's from the decay . The resolution is comparable in CLEO II and CLEO III. This is also true for the mass shown in Fig. where the has been reconstructed through its mode.

As another example, we consider the rare decay where the then decays to . This is an interesting decay since it may be used to observe CP violation in a symmetric machine environment. In Fig. we show the reconstructed mass and in Fig. we show E, the energy difference between the beam energy and the sum of the and energies. Again, comparable performance for CLEO III relative to CLEO II has been achieved.

As yet another example we consider the rare decay . In Fig. we show the reconstructed mass resolution for CLEO II and CLEO III. In Fig. we also show the difference between the beam energy and the total energy of the two pions and the mass for a constrained fit using the beam energy and the reconstructed momenta. Again, comparable performance to CLEO II has been maintained.

In Table we present a summary of the results obtained in the physics simulations as shown in Figs. -. Over a wide range of physics modes, the CLEO III detector maintains the excellent performance of CLEO II. As stated earlier, additional gains may be made by using CLEO III specific tracking reconstruction code and by more appropriate placement of the tracking layers. This work in presently underway.