In this section we want to give an overview of the variables that are defined in the program and, therefore, can be histogrammed and used in the definition of logicals. Most of the variable names are preceded by a string indicating to which spectrometer and/or detector they belong. Figure 1 gives an overview of the variables and a tree-like structure guiding the user how to compose the variable string.
Figure: Structure guuiding the user how to compose the variable string.
Starting at the top of the tree, the user has two options: choose a variable
which is a function of the output of both spectrometers or select a variable
linked to one of the spectrometers. In the first case there is no string, so
the missing energy is simply referenced by e_miss. However, in the
second case the string will start with the spectrometer name: spec_e
or spec_h. The black dot at the bottom of the box indicates that the
user should go at least one level deeper to have a valid variable name. The
next choice is between a kinematic variable or a variable connected to one of
the detectors, f.i. spec_e.p (the momentum of the particle detected
in the electron spectrometer) or spec_e.s1... . In the last case
the user has to go one level deeper, indicating the variable of that detector.
Below we will discuss three tables in which the variables are grouped according to the number of levels in the variable string. We start with the variables constructed with the output of both spectrometers.
Table: Level one variables, involving both spectrometers.
A '*' behind the variable name of the tables 1,
2, 3 and 4 indicates
that the histogram of this particular variable is updated even when the
necessary detectors did not fire. For instance, the number of hits in
a scintillator would be updated even when this detector did not fire.
For level 3-variables
which detector had to fire is obvious from the variable string. Level-2
variables are a bit more complicated variables which are composed out of the
response of several detectors. Here, the histogram is updated when the
trigger detector of the spectrometer fired. For level-1 variables either
the trigger detectors of both spectrometers should have fired in case of
coincidence variables or no detector is necessary at all like for the
variable event_type.
Table: Level two variables, involving one spectrometer.
Table: Level three variables, involving the VDC detectors.
spec_s can be either spec_e or spec_h
Table: Level three variables, involving detectors in the
spectrometers. spec_s can be either spec_e or spec_h
