Dsh analysis meeting minutes 20-01-11

Present : Vava, Sajan, Barbara, Nico

On Evo : Mariusz, Piotr, Niels, Tim


Piotr :
Presented status of the fitter. For the DPi fit, there is a significant difference between using CB+Gaus or just CB. Needs to be understood. Novosibirsk function seems able to fit the shape of the misidentified signal, however the DK MC fits need to be redone using the MC misidentification, not the data misidentification.

Nico, Barbara:
Showed fits with and without reweighting, the fits without reweighting are clearly biased but the fit is not noticeably worse by eye. The conclusion is that the reweighting procedure is definitely necessary in order to have an accurate fit.

Has tried NeuroBayes, training using data alone looks very promising (and has obvious conceptual advantages). Would be interesting to try discriminating against prompt charm separately from pure combinatorics.

Action Items

Signal shape
We need to establish the differences between fitting with a CB, CB+Gaus, Double CB, or just a Gaus for the next note version. First of all need to fit to the signal MC alone (select background categories 0,10 and 50 in order to include the radiative tail in the fits), then whichever gives the best fit quality should be used in the full fits. If fitting a double CB or CB+gaus need to fix the means to be identical.

Data fits
Need to perform the fit for different BDTG values, probably necessary to fix the DPi contribution in the DK fit (from the mis ID) for the looser BDTG values in order to ensure an unbiased fit.

-- VladimirGligorov - 20-Jan-2011

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Topic revision: r1 - 2011-01-20 - VladimirGligorov
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