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JeffersonLab / HDGeant4

Geant4 simulation for the GlueX experiment
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Negative counts on eta invariant mass spectrum for 2017 simulation #173

Closed KMahmoud closed 4 years ago

KMahmoud commented 4 years ago

Please see the attached plots. KinFit quantities are used. hdgeant_8_11_2020.pdf

KMahmoud commented 4 years ago

Measured quantities does not show this negative counts. See the figures BE_Etamass_Measured.pdf BE_Etamass_Measured.pdf Eta_mass_Measured.pdf

sdobbs commented 4 years ago

Thanks, that's interesting - is there a difference in the weights used or how you are handling the combinatorics between the measured and kinfitted quantities?

KMahmoud commented 4 years ago

No, there is no difference at all in the weights nor in handling the combinatorics.

KMahmoud commented 4 years ago

I'm closing this issue because Justin helped me figuring out the origin of the problem. In my code I have a double uniqueness tracking, one on the missing mass, and the second is on the final state photons only, which is not correct to use with the accidental subtraction.