UCAL Condensates

A ``condensate'' is an object which contains calorimeter cells which are clustered together. The standard ZEUS UCAL reconstruction program CCRECON (see [36]) creates condensates of neighboring cells if they have a common surface.

MUFFIN uses a separate program `` CONDENSOR'' to construct condensates. Here cells are also neighbors if they touch each other on a common edge or corner (see figure 6.4).

Figure 6.4: Schematic view of a muon traversing UCAL cells. From the cells with enough energy to pass the noise cuts CCRECON (on the left) constructs three condensates as shown by differently shaded boxes while CONDENSOR (on the right) only constructs a single condensate.

In CONDENSOR the extreme towers of BCAL can also have neighbors in FCAL or RCAL. CONDENSOR knows of two different neighborship relations: Cells are neighbors when either their projections on the $X-Y$ plane overlap or if a straight line through (,,) hits both cells. Unlike CCRECON CONDENSOR does not remove condensates with little energy. CONDENSOR also performs a line fit to the cell centers and uses this line to calculate shape parameters such as the ``hit ratio'' which is the ratio of the number of cells hit by the trajectory over the total number of cells. These parameters are used by the muon finder to speed up calculations.