1. CMS (Tracker) Alignment
CMS features one of the most complex tracking systems ever built
performance depends critically on accurate alignment
formidable alignment problem (in full detail >50000 free parameters)
most promising solution: MillePede-II algorithm
CMS DESY people actively involved:
Rainer Mankel (Staff, since ~May 2007)
Claus Kleinwort (Staff, from ~Jan 2008)
Silvia Miglioranzi (Fellow, since ~Sep 2007)
Andrea Parenti (Fellow, since mid Nov 2007)
Johannes Hauk (Diploma student, since ~Jul 2007)
In close collaboration with CMS group of Univ. Hamburg
Gero Flucke (PostDoc)
Erik Butz (PostDoc)
Kolya Kaschube (PhD student)
Volker Blobel (Emer.)

2. CMS Alignment (cont’d)
DESY has been responsible for performing the MillePede alignment exercise for the CSA07 challenge in Oct’07
1.7 M of simulated Z events, ~12000 parameters
full production chain
from AlCaReco files to database, performed on CAF
first alignment constants uploaded after 3 hours
~2 m precision
the first CSA07 exercise to be completed!
DESY has significantly contributed to alignment monitoring, in particular in the context of the TIF data analysis
We participate in the project of demonstrating MillePede alignment with minimum bias events (essential for startup!), and will probably take part in alignment with the first cosmics taken in UX5
R.M. will coordinate CMS alignment starting from Jan 2008
(u) ~ 2 m
Misaligned
Pass 1
Pass 2
Pass 3
before
after alignment