S&C meeting 10-05-2005

For the SSD, several runs were recently processed by Lidia :
RunBeamFieldSize
6049030CuCu@200B=FF100 kevents
6049032CuCu@200B=FF100 kevents
6065037CuCu@200B=0157 kevents
6065045CuCu@200B=0157 kevents
6073006CuCu@62B=FF238 kevents

Alignment

The global alignment is done is few steps. The SSD is considered as a solid object. Translations in X, Y and Z and rotation in Phi are determined and corrected for in the global positionning of the SSD. The translation in Z was determined by centering at zero the dy residual of the ladder 16.
No corrections Correction for a shift in X. dX=0.418 cm
In addition, correction for a shift in phi : dPhi=0.0181 rad In addition, correction for a shift in Z. dZ=-0.083 cm

After this global alignment, the situation for individual ladders can be investigated. For instance the residual in x versus the z position.
At this stage to go further, we needed more statistics. We first tried to process some events ourself. We ended up with alignment results depending on the run characteristics : Beam, Field and the tracks used (primaries versus global). That's why we placed the request to have a set of runs reconstructed with the official chain.
So clearly the statistics was better especially because only 1/20 of a given new run was used to build the plot above. We then checked the plots for the different runs : Cu+Cu @ 200 Full Field
Cu+Cu @ 200 No Field
Cu+Cu @ 62 Full Field
dca versus phi (Cu+Cu @ 200 Full Field)
dca versus phi (Cu+Cu @ 62 Full Field)
Lilian MARTIN
Last modified: Fri Mar 11 16:21:29 CET 2005