A Classic Thesis Style - Johannes Gutenberg-Universität Mainz

3.8 scaling method for cross-section extraction and monte carlo simulation 77
The corresponding error in spectrometer B was known to be much
smaller due to the long experience in its use and the corresponding
improvement in its model, tested several times in measurements of
well known cross-sections. A contribution to the total systematic error
of 1% was assumed.
Figure 48: Phase-space for kaon scattering angle vs. kaon momentum in
Kaos spectrometer simulated by the Monte Carlo method (top)
and measured during the 2009 beam-time (bottom). The kaon data
were extracted after particle identification and missing mass cuts.
The simulation includes radiative corrections and energy-loss in
the target.
Radiative corrections were fully incorporated on the electron arm
but no attempt to include them for the charged kaon was done since
their contribution was known to be much less significant. This small
systematic error is directly related with the tail in the missing mass distribution.
A fitted phenomenological model was used to minimize the
relevance of this error. Its contribution was estimated in comparison
with the effect on the electron arm to be of the order of 1%.
According to the Geant simulation, the products of in flight Kaon
decay had a very small probability to be mistaken in the event reconstruction
as kaons. The simulation proved that they typically differed
by energy deposition and/or time of flight. Tracking trigger also excluded
decaying particles out of the angular acceptance defined by
paddle combinations. In Fig. 49, detection efficiency is given as a function
of momentum for the case where decaying particles are accepted