1. Oxford 09 October 2003 ID Alignment Meeting Pawel Brückman de Renstrom Software 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 Meeting University of Oxford 07/10/03

2. Oxford 09 October 2003 ID Alignment Meeting Pawel Brückman de Renstrom  Potential problem pointed out during last meeting: strangely mixed modes???  Just an artefact of inversed tilt angles in the display program: beforeafter No indication for mixed modes any more!

3. Oxford 09 October 2003 ID Alignment Meeting Pawel 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

4. Oxford 09 October 2003 ID Alignment Meeting Pawel Brückman de Renstrom Reminder: “lowest modes” in PIX+SCT as reconstructed from the old ntuples

5. Oxford 09 October 2003 ID Alignment Meeting Pawel 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)

6. Oxford 09 October 2003 ID Alignment Meeting Pawel 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)

7. Oxford 09 October 2003 ID Alignment Meeting Pawel Brückman de Renstrom Mode # eigenvalue 0 0.0000000000 1 2 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/db  de/da) for translations

8. Oxford 09 October 2003 ID Alignment Meeting Pawel Brückman de Renstrom Mode # eigenvalue 40.0006027754 50.0006612646 60.0023209506 70.0023502892 PIX+SCT Ring, VTX fit (DC1 ntuple: 23kev)

9. Oxford 09 October 2003 ID Alignment Meeting Pawel 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

10. Oxford 09 October 2003 ID Alignment Meeting Pawel 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!

11. Oxford 09 October 2003 ID Alignment Meeting Pawel 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!

12. Oxford 09 October 2003 ID Alignment Meeting Pawel 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!