4-9 June 2012
Life Sciences Centre, UBC
Canada/Pacific timezone
<strong><font color="#cc0000">Abstract submission has closed</font></strong>

Combining b-tagging calibrations in ATLAS

4 Jun 2012, 16:00
West Atrium (Life Sciences Centre, UBC)

West Atrium

Life Sciences Centre, UBC

University of British Columbia Vancouver, BC Canada
Poster Heavy Flavour Physics 1D: Poster Session and Coffee Break


Gordon Watts (University of Washington (US))


The ATLAS collaboration calibrates its b-tagging algorithms using a number of data-driven methods. The b-tagging algorithms, used to separate b-quark jets from light-quark jets, are widely used in top, Higgs, and Exotics analyses in ATLAS. The algorithm’s performance is measured for light-quark jets, charm jets, and bottom jets. In some cases multiple methods can be used to measure the performance: methods using di-jet data and a pure sample of top-quark pair production are be used to measure the bottom-quark jet performance. These methods have complementary strengths – the di-jet methods tend to have the smallest errors at low jet energy, and the ttbar methods tend to have smaller errors at high jet energy. We used a minimum likelihood method to fit the results, profiling common systematics, to combine the results. For results on common data we have also understood the statistical correlation of our methods. This poster will describe the details of the combination.

<strong>Collaboration Name</strong><br /><font color="#000099">Please enter the name of<br />the collaboration or group<br />using the acronym, as in:<br /><font color="#ff0000">ABC Collaboration</font>

ATLAS Collaboration

<strong>E-mail Address</strong> gwatts@uw.edu

Primary author

Gordon Watts (University of Washington (US))


Presentation Materials