Mihael MakekWeizmann Institute of Science

HBD Meeting, 8/12/2010

Detector movements during Run-10

Run(s) selected for alignment

• Goal: determine time variations of HBD offsets• Selected data: CCNT - hadrons

• Good quality tracks (31,51,63)• n0 < 0• Emcal matching

• Selected subsample:• p > 0.7 GeV/c• Hbdsize = 1• Restricted geometry in HBD modules• Centrality > 50%

The dataset

Sign dependence

Select particles with p > 0.7 GeV/c to avoid sign dependence

Matching in phi (run 307035)

Matching in z (run 307035)

Offsets in phi

The blue line – weighted average EASTThe red line – weighted average WEST

Offsets in zZ-offsets for East and West are moving synchronously cannot be connected with carriage movements.

BBC calibration?Beam related?

The blue line – weighted average EASTThe red line – weighted average WEST

Check the systemactics of the methodLook at two very close runs:

the difference comparable or smaller than the errors

Offsets in phi - table

Offsets in z - table