Oxford09 October 2003
ID Alignment MeetingPawel Brückman de Renstrom
Software Prototype – recent updatesSoftware Prototype – recent updates
Pawel Brückman de Renstrom
• Just a few observations• No real work done since last meeting• Verification of derivatives tedious – subtle
effects seem to play role!• The proof-of-principle exercise will not be
conclusive unless we start using the “exact” derivatives
ID Alignment MeetingUniversity of Oxford 07/10/03
Oxford09 October 2003
ID Alignment MeetingPawel Brückman de Renstrom
Potential problem pointed out during last meeting: strangely mixed modes??? Just an artefact of inversed tilt angles in the display program:
before after
No indication for mixed modes any more!
Oxford09 October 2003
ID Alignment MeetingPawel Brückman de Renstrom
Switch to the latest ntuples from DC1 including exact Z information for extrapolations to the SCT Reminder: I could not observe “low modes” corresponding to global rotations around X & Y on the old ntuples. Reason: derivatives v.r.t. local in-plane rotations of modules are proportional to local_y! New ntuples perfectly cure the problem – just as expected!
NOTE: The DC1 multimu ntuple has over twice smaller statistics than the old one – larger fluctuations observed
Oxford09 October 2003
ID Alignment MeetingPawel Brückman de Renstrom
Rem
ind
er:
“lo
wes
t m
od
es”
in P
IX+
SC
T a
s re
con
stru
cted
fro
m t
he
old
ntu
ple
s
Oxford09 October 2003
ID Alignment MeetingPawel Brückman de Renstrom
Mode #
eigenvalue
0 0.0000000000
1 0.0000072838
2 0.0001599211
3 0.0001632777
PIX+SCT Ring, no VTX (DC1 ntuple: 23kev)
Oxford09 October 2003
ID Alignment MeetingPawel Brückman de Renstrom
Mode #
eigenvalue
4 0.0003927623
5 0.0004008616
6 0.0005043090
7 0.0007637286
PIX+SCT Ring, no VTX (DC1 ntuple: 23kev)
Oxford09 October 2003
ID Alignment MeetingPawel Brückman de Renstrom
Mode #
eigenvalue
0 0.0000000000
1 0.0000000000
2 0.0000000000
3 0.0000243961
PIX+SCT Ring, VTX fit (DC1 ntuple: 23kev)
NOTE: now three translations are distinct. The reason being the direct numerical matching of the derivatives (de/dbde/da) for translations
Oxford09 October 2003
ID Alignment MeetingPawel Brückman de Renstrom
Mode #
eigenvalue
4 0.0006027754
5 0.0006612646
6 0.0023209506
7 0.0023502892
PIX+SCT Ring, VTX fit (DC1 ntuple: 23kev)
Oxford09 October 2003
ID Alignment MeetingPawel Brückman de Renstrom
So I was happy and relaxed untill… BUT… wait a moment. There should NOT be 6 exact degeneracies of the system! B field has a direction:
It simply shouldn’t work!
B
Oxford09 October 2003
ID Alignment MeetingPawel Brückman de Renstrom
And I realised that the “SUPERsymmetry” I obtain was due to oversimplified calculation of de/dcot. It didn’t correctly treat hits further down the helix. After correction…
…again everything as expected!
Oxford09 October 2003
ID Alignment MeetingPawel Brückman de Renstrom
PIX+SCT Ring, no VTX (DC1 ntuple: 23kev)
Mode #
eigenvalue
0 0.0000000000
1 0.0000012014
2 0.0003974228
3 0.0004080927
de/dcot corrected!
Oxford09 October 2003
ID Alignment MeetingPawel Brückman de Renstrom
PIX+SCT Ring, no VTX (DC1 ntuple: 23kev)
Mode #
eigenvalue
4 0.0007558214
5 0.0007961715
6 0.0013165807
7 0.0013501549
de/dcot corrected!