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## Jets calibration using events | |||||||||||||||||||||||||||||||

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http://cmssw.cvs.cern.ch/cgi-bin/cmssw.cgi/UserCode/Bicocca/HiggsAnalysis/TTBarAnalysis/
## How | |||||||||||||||||||||||||||||||

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< < | How to prepare the environment for the analysis | ||||||||||||||||||||||||||||||

> > | How to prepare the environment for the analysis:
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cmsrel CMSSW_3_3_4 cd CMSSW_3_3_4/src/ | |||||||||||||||||||||||||||||||

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cd HiggsAnalysis/TTBarAnalysis scramv1 b | |||||||||||||||||||||||||||||||

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## Results | |||||||||||||||||||||||||||||||

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> > | with = / and = / | ||||||||||||||||||||||||||||||

- MiB : Minuit Bare minimization
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- SFit: Squared Fit
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> > |
## MiB : Minuit Bare minimizationMinimization in space of the function assumingmassless jets, using TMinuit package.
Result: still invariant mass underestimation!
## kUpdateAnalytic minimization of . Result: No iterative method: just one step!Result: invariant mass overestimation!
## RUL3 : Random Update L3As L3 method but withrandom update that is: after analysing all the events, not every k is update but only a random sample (tipically one half of the k space). This method is intrinsically iterative, that is many k updates are required.
Why random update? L3 method works fine for "intercalbrations", that is the mean value of
## SL3: Squared L3As L3 method, but with the ratio of the masses instead of the squared ratio then the "dimension" of the correction is proportional tok and convergence is reached.
## RUFit : Random Update FitFitting the invariant mass spectrum for a fixedk, that if filling an invariant mass spectrum for all jet pairs where at least one of the two jet is in the selected bin in k space, and imposing the invariant mass peak to be the right one
but with random update that is: after analysing all the events, not every k is update but only a random sample (tipically one half of the k space), see RUL3 for details. This method is intrinsically iterative, that is many k updates are required to k values to converge.
Result: not performing!
## SFit: Squared FitFitting the invariant mass spectrum for a fixedk, that if filling an invariant mass spectrum for all jet pairs where at least one of the two jet is in the selected bin in k space, and imposing the invariant mass peak to be the right one
This method is iterative, that is many k updates are required to k values to converge.
## SL3: Squared L3As L3 method, but with the ratio of the masses instead of the squared ratio then the "dimension" of the correction is proportional tok and convergence is reached.
## Summary
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## Jet from W identification in events |

View topic | History: r6 < r5 < r4 < r3 | More topic actions...

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