Two approaches were taken to measure the efficiency of the segment finding algorithm.
The segment finding analysis has been performed with different fiducial cuts and segment finding algorithm parameters. Unless otherwise stated the following values for the parameters of the algorithm were used,
This choice of parameter values seems reasonable since five hits are expected in a cell on average [2] and at least three are needed to form a segment. Unless otherwise stated the following fiducial cuts were applied,
Fiducial cut 1 selects the most interesting tracks and
reduces confusion from low secondary tracks.
Fiducial cut 2 is the geometrical acceptance (in the
forward direction) for four hits in superlayer three.
This geometrical acceptance should alway contain the
electron from NC events provided
is greater than
100 GeV
.
Figure 4 displays the segment finding
performance for a NC event.
Both signs of the ambiguous drift direction,
inefficiencies, and noise hits are shown in
figure 4a, while the found segments are shown
figure 4b.
It can be seen that adequate segments are found to enable
the high tracks to be found in this event.
Figure 4: Display for a NC event: a) hits,
and b) found segments. A) B)