The semileptonic branching ratios of the 
can be measured at
DA
NE by selecting the following final states
, where
, 
and 
is one
of the allowed final states in 
decays
(
or 
).
The probability of such events is obtained by
integrating eq. (5)
in the appropriate time intervals.
Therefore the number of events for
initial 
pairs is given by:
where
As can be seen, 
is by far the dominant contribution; the branching
ratio products in eq. (25)
are predicted to be of the same order, while the interference
term should be further suppressed by large cancellations.
Therefore inserting the experimental value [24]
eq. (25) becomes:
The project luminosity of DA
NE (
)
gives about 
/year.
Using eq. (22) and the present upper limit on the
violation of the 
rule [24], we estimate
and 
,
therefore 
events/year are expected.
With these numbers we can estimate the sensitivity of DA
NE to CP, CPT
and the 
rule violating parameters defined in
eqs. (23) and (24).
Since the 
final state
can hardly be distinguished
from the 
one, we conservatively assume that
only electrons can be used to derive 
charge asymmetry.
In this case the number of event is 
/year
and the statistical error
on 
turns out to be 
.
Since the experimental value of 
charge asymmetry is
[24], we expect 
,
testing the CPT prediction 
at a significant level.
Eq. (24) (test of 
rule) involves
the semileptonic rates of 
and 
;
thus to estimate the error on 
one has to take into account also the experimental errors on tagging
branching ratios and on 
widths. Using the values in
Ref. [24], these effects give a large contribution to the total error,
which turns out to be 
, whereas
the pure statistical contribution would give only 
.
This large value for 
will perhaps be lowered by
measuring all the quantities involved in the same experimental set-up.
Table 1: Comparison between the present experimental data
[24],
CPLEAR present and expected sensitivity
[25] and the
achievable sensitivity in 1 year at DA
NE, for the semileptonic
parameters. For both CPLEAR and DA
NE only the statistical
error has been reported. Note that 
and 
asymmetries
have different theoretical expressions, for
CPLEAR and DA
NE, if one considers CPT
violation in the decay amplitudes.
In Table 1 we report the predicted sensitivity of DA
NE in
comparison with other experiments.
As one can see, DA
NE
is very powerful to test 
rule.
