Violation in Mixing

116 Strategy and Tools for Charmless Two-body � Decays Analysis
Events/20 MeV
Events/20 MeV
1500
1000
500
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Offres Data
B A B AR
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-0.4 -0.2 0 0.2 0.4
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udsc MC
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Figure 4-10. The distribution of ¡� for the entire region of on-resonance data, side-band and signal, is
given by the points with error bars in both plots. The solid curve represents a fit of a second order polynomial
to the side-band regions only (�¡�� � � �). The histogram in the upper plot is off-resonance data and
the histogram in the lower plot is continuum Monte Carlo data (both normalized to the same area as the
on-resonance distribution).
The ¡� PDF for a decay with a à in the final state consists of a Gaussian with a mean given by the
following analytical form [54]:
�Õ Õ �
ÅÃ Ô Å� Ô � (4.13)
�¡�� � ­�ÓÓ×Ø ¢
where Ô is the momentum of the assumed kaon track.
4.6.4 Fisher output �
The distribution for � for the background is determined from events in the Ñ�Ë side-band region of the onresonance
sample since the statistics are large and the sample is free from contamination from �� events.
The distribution is parameterized by the sum of two Gaussians, as shown in Figs. 4-12. The points are
the Ñ�Ë side-band data and the overlayed histograms are the distributions obtained from off-resonance and
Monte Carlo simulated continuum events, using the full Ñ�Ë region (�� -�� ��Î� ). These alternative
parameterizations are used in computing systematic uncertainties due to the � parameterization.
MARCELLA BONA