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Top Mass Group

Top Mass

This page is devoted to analysis performed in order to measure the top quark mass, with early data and further, in all ttbar channels. The work performed inside this subgroup is done in close collaboration with the performance groups, and the top reconstruction group. We will follow two main directions:

• very early data: top mass measurement can be used to understand and calibrate the light jet energy scale and the b-tagging.
• work on a precise top mass measurement: systematics uncertainties estimate, and channel combination.

Organization

An hypernews forum has been created for top mass analysis: please subscribe to this forum if you are interested in top mass analysis. Meetings will be held twice a week (announcements will be made through hypernews), usually on Tuesday. We would like to identify people of the group that could be our contact with performance groups (in particular jet/ETmiss, b-tagging), Monte Carlo, and Top Reconstruction groups.

Monte Carlo production

Monte Carlo production for 2008 (10 TeV) and 2009 (10 TeV) is coordinated by Akira Shibata; status of the production can be found in the Top MCpage. For top mass analysis, the following samples are useful:

physics	dataset	generator	sqrt(s)cross section	number of events
l+jet & di-lepton tt	5200	10 TeV	Mc@NLO	230

Data format

AOD and primary DPDs will be produced centrally, probalby shared with Standard Model group. The content of DPDs is being discussed and we are encouraged to give feedback; information can be found here.

Common tools

There are two kind of tools:

• Algorithms defined in the Top Reconstruction group: we will of course use them, and participate to this effort in particular for jet calibration.
• Tools defined inside our subgroup, more specific to the top mass subgroup.

Contributors

Lepton+jets channel

• CEA-Saclay
• Clermont-Ferrand (LPC, IN2P3)
• Dortmund

Di-lepton channel

• CEA-Saclay
• Prague
• Paris (LPNHE, IN2P3)
• Tufts

All-jets channel

Top mass measurement from the cross section measurement

Documentation

CSC note

Tevatron results

CERN Yello wReport

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Major updates:
-- AnneisabelleEtienvre - 25 Sep 2008