Violation in Mixing

3.3 Studies on data 89
N(π + π - ) candidates / 1.7 MeV/c 2
N(π + π - ) candidates / 1.7 MeV/c 2
x 10 2
2000
1750
1500
1250
1000
750
500
250
0
x 10 2
2500
2000
1500
1000
500
0
observed Ks candidate invariant mass
186.9 / 52
P1 0.2127E+06 825.7
P2 -0.1745E+06 1625.
P3 0.3724E+06 3023.
P4 0.4973 0.2059E-04
P5 0.2620E-02 0.3667E-04
P6 0.5365 0.1232E-01
P7 0.4966 0.1141E-03
P8 0.7994E-02 0.2672E-03
M(π + π - ) (GeV/c 2 0.46 0.48 0.5 0.52 0.54
)
Observed Ks candidate invariant mass
414.7 / 52
P1 0.2313E+06 852.4
P2 -0.1791E+06 1690.
P3 0.5552E+06 2788.
P4 0.4985 0.1174E-04
P5 0.2157E-02 0.2137E-04
P6 0.5221 0.7657E-02
P7 0.4979 0.6207E-04
P8 0.6847E-02 0.1345E-03
M(π
Ks mass
+ π - ) (GeV/c 2 0.46 0.48 0.5 0.52 0.54
)
N(π + π - ) candidates / 1.7 MeV/c 2
N(π + π - ) candidates / 1.7 MeV/c 2
x 10 2
2250
2000
1750
1500
1250
1000
750
500
250
0
x 10 2
3000
2500
2000
1500
1000
500
0
observed Ks candidate invariant mass
153.5 / 52
P1 0.2312E+06 854.0
P2 -0.1996E+06 1680.
P3 0.3822E+06 2900.
P4 0.4974 0.2141E-04
P5 0.2566E-02 0.3550E-04
P6 0.5480 0.1207E-01
P7 0.4963 0.1197E-03
P8 0.7780E-02 0.2487E-03
M(π + π - ) (GeV/c 2 0.46 0.48 0.5 0.52 0.54
)
Observed Ks candidate invariant mass
281.6 / 52
P1 0.2702E+06 877.9
P2 -0.2360E+06 1733.
P3 0.5641E+06 2809.
P4 0.4985 0.1102E-04
P5 0.2123E-02 0.1853E-04
P6 0.5530 0.7762E-02
P7 0.4980 0.6626E-04
P8 0.6689E-02 0.1453E-03
M(π
Ks mass
+ π - ) (GeV/c 2 0.46 0.48 0.5 0.52 0.54
)
Figure 3-9. Top plots: Ã Ë candidate invariant mass in both block 1 (left) and block 2 (right) samples of
the on-resonance data. Bottom plots: Ã Ë candidate invariant mass in both block 1 (left) and block 2 (right)
of the Monte Carlo samples. The superimposed curves are the results of the fit with a double Gaussian and a
linear background.
Fig. 3-14 shows the values of the corrections as function of the 2-dimensional flight length: the red dots
represent the corrections with the 1GeV momentum cut, while the black one are the values obtained from
the no momentum-cut sample.
To evaluate the correction and its error in a specific analysis, one should apply both sets of corrections
separately and then take into account the difference as a systematic error on this correction. The central
value of the correction should be the one given from the set with the momentum cut, since in that case
the extraction of the correction is cleaner (statistical error on the correction is smaller) due to a lower
background.
In the case of a single Ã Ë and given the � sample where � runs over block 1 and block 2, the correction � �
is given by:
� � � �
�
�� ¡ Ü � �
Ã Ë RECONSTRUCTION AND EFFICIENCY STUDIES