Run 9, pp200 GeV Full Field (FF) - new calibration (May 2012)

 

Below are the resulting beamline intercept parameters with the new calibration from 2012. The black markers were removed due to low

statistics. 

 

The slope parameters:

 

The direct comparison to the previously used 3D method shows some systematic differences. This could be either due to the new calibration parameters or due to systematics between the methods itself. We have compared the results from the 2D method for the new and old calibration parameters and could not find significant differences. Below are the values for old and new for one daq file (st_physics_10156091_raw_8030002.daq) and 5000 analyzed events. The pile up was always suppressed by requireing the highest ranked vertex. 

parameter	old	new
x	0.3613	0.3651
y	-0.004416	-0.01654
dxdz	0.001005	0.001096
dydz	9.934157e-05	0.0001507

It was decided to use the 2D results for the parametrization of the beamline. All parameters were uploaded to the database with +1 second offset to the timestamp.