Alliance Workshop on Unfolding and Data Correction

27 May 2010, 13:00 → 28 May 2010, 16:00 Europe/Berlin

SR 4a (DESY Hamburg)

Thomas Schoerner-Sadenius (DESY)

The issue of data correction and data unfolding will play a crucial role for a number of measurements (not only) in the early LHC data. Furthermore, a number of more or less well-motivated and well-implemented methods exists which (and the arguments for and against which) are not necessarily familiar to the relevant community. This workshop at DESYHamburg will focus on the topic of unfolding and data correction. The aims of the workshop are - to get an overview of the various tools that are being used for unfolding purposes at HERA, Tevatron and LHC - to discuss the advantages and disadvantages of the various methods, and to collect the benchmarkings that have been done so far - to discuss the various implementations and their shortcomings - to come up with a strategy for further implementation, improvement and promotion of some of the tools. The meeting will be transmitted by EVO: Title: Analysis Centre Seminars Description: Analysis Centre Seminars Community: Terascale Phone Bridge ID: 1312410 Meeting URL: http://evo.vrvs.org/evoGate/koala.jnlp?meeting=MaMDMt222sDeDi9M98DI9a In case of questions, don't hesitate to contact the organisers at anacen@desy.de.

Thursday, 27 May

14:00 → 14:05 Welcome

Speaker: Dr Thomas Schoerner-Sadenius (DESY)

Slides welcome.pdf

14:05 → 14:10 Introduction to the subject

Speaker: Prof. Arnulf Quadt (II. Physikalisches Institut, Georg-August-Universität Göttingen)

14:10 → 14:40 Improved iterative Bayesian unfolding

This paper reviews the basic ideas behind a Bayesian unfolding published some years ago and improves their implementation. In particular, uncertainties are now treated at all levels by probability density functions and their propagation is performed by Monte Carlo integration. Thus, small numbers are better handled and the final uncertainty does not rely on the assumption of normality. Theoretical and practical issues concerning the iterative use of the algorithm are also treated. The new program, implemented in the R language, is freely available, together with sample scripts to play with toy models.

Speaker: Giulio d'Agostini (Rome)

Slides unf2_hh.pdf

14:40 → 15:10 Multidimensional binning-free unfolding method

Speaker: Guenter Zech (Siegen)

Slides

• unfolding2010_4.pdf
• unfolding2010_4.ppt
• unfolding_gen.pdf
• unfolding_gen.ppt

15:10 → 15:40 Unfolding requirements and some details on algorithms and problems related to unfolding

Speaker: Prof. Volker Blobel (Uni HH)

Slides VBL_Talk.pdf

15:40 → 16:00 Coffee break

16:00 → 16:20 Discussion on some unfolding issues

Speaker: Guenter Zech (Siegen)

Slides unfolding_gen.ppt

16:20 → 16:40 Decomposition of a covariance matrix into uncorrelated and correlated errors

Speaker: Benno List (Hamburg)

Slides stat-ws.pdf

16:40 → 17:00 Comparison of methods

Speaker: Katharina bierwagen (Goettingen)

Slides Unfold_new.pdf

17:00 → 18:00 Discussion session: Basics, concepts, missing implementations ...

Friday, 28 May

09:05 → 09:25 Implementations: RooUnfold

Speaker: Tim Adye

Slides 100527-unfold.pdf

09:25 → 09:45 Implementations: TRUEE

Speaker: Natalie Milke

Slides TRUEE_Unf_Workshop.pdf

09:45 → 10:05 Implementations: TUnfold

Speaker: Michel Sauter (Universitaet Heidelberg)

Slides TUnfold_Sauter.pdf

10:05 → 10:25 Discussion: Implementations

10:25 → 10:45 Coffee break

10:45 → 11:05 Experience / benchmarkings: CMS

Speaker: Thomas Peiffer (Karlsruhe)

11:05 → 11:25 Experience / benchmarking: Unfolding in ATLAS

Speaker: Marisa Sandhoff (Wuppertal)

Slides sandhoff.pdf

11:25 → 11:45 Experience with GURU

Speaker: Sebastian Eckweiler (Mainz)

Slides GURU_Erfahrungen.pdf

11:45 → 12:05 Experience / benchmarking: Unfolding in ATLAS

Speaker: Mr Deepak Kar (University of Florida)

12:05 → 13:05 Discussion: next steps?