Violation in Mixing
Violation in Mixing
Violation in Mixing
Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
150 Measurement of Branch<strong>in</strong>g Fractions for � � Ã Ë Ã Ë Decays<br />
Table 6-1. Summary of Ã Ë Ã Ë selection efficiency.<br />
Cut Efficiency<br />
reco + tag bit + Ê + Sphericity �� ¦ � �<br />
� Ó× �Ë� � �� � �� ¦ � �<br />
ØÃË��Ø � � � �� ¦ �<br />
¬<br />
¬<br />
Å � � Å Ã ¬ Ë � � Å�Î� � �� ¦ �<br />
resonance Ñ�Ë side-band <strong>in</strong> the second case, we estimate the best upper limit we can obta<strong>in</strong> from each of<br />
them <strong>in</strong> order to establish the best method to use. Before be<strong>in</strong>g able to test these techniques, we performed<br />
the validation of the variables used <strong>in</strong> both the global likelihood fit and the count<strong>in</strong>g analysis.<br />
6.2.1 Efficiency<br />
Table 6-1 summarizes the efficiency of the Ã Ë Ã Ë selection which corresponds to the usual two-body one<br />
(see Sec. 4.2.1). Tak<strong>in</strong>g <strong>in</strong>to account a m<strong>in</strong>imal � Ó× �Ë� cut at the value of �� and no Fisher cut, the total<br />
efficiency is ��� ¦ � . All efficiency estimates are derived <strong>in</strong> Monte Carlo except for the Ã Ë mass cut<br />
efficiency, which was estimated from the � � Ã Ë � control sample to be �� ¦ .<br />
Corrections to the efficiency value, account<strong>in</strong>g for the two Ã Ë reconstruction, are then <strong>in</strong>cluded (see Sec. 3.3.4).<br />
These corrections amount to � �¦ � ×Ø�Ø� ¦ � ×Ý×Ø� for the two à Ë. Other systematic effects come<br />
from the � Ó× �Ë � cut ( ) and the Ã Ë mass cut ( per Ã Ë candidate). This contribution was estimated<br />
from the difference between the MC efficiency and that of the � � � Ã Ë control sample. Another<br />
contribution to efficiency systematics is a �� com<strong>in</strong>g from the charged tracks reconstruction uncerta<strong>in</strong>ty<br />
<strong>in</strong> Ã Ë reconstruction.<br />
The f<strong>in</strong>al number for efficiency is<br />
��� ¦ ���<br />
6.3 The maximum likelihood analysis<br />
We use the same unb<strong>in</strong>ned maximum likelihood fit technique developed to determ<strong>in</strong>e from the data:<br />
¯ Æ Ë , the number of � � Ã<br />
ÃËÃ ËÃË decays;<br />
Ë<br />
¯ Æ � , the number of background Ã<br />
ÃËÃ ËÃË candidates;<br />
Ë<br />
MARCELLA BONA