I have another issue. I tried different combinations of PID algorithms and found out a strange thing.

For example if I use following code with "PidAlgoEmcBayes" enabled only

theAnalysis->FillList(eplus, "ElectronVeryTightPlus","PidAlgoEmcBayes");

or another one with many others included

theAnalysis->FillList(eplus, "ElectronVeryTightPlus","PidAlgoEmcBayes;PidAlgoStt;PidAlgoMvd;PidAlgoDrc;PidAlgoDisc;PidAlgoMvd");

then the first case gives me less events compare to the second one. It seems very strange for me. I would expect that by adding new algorithms I should be getting less rather then more events.

Cheers,

Dmitry]]>

the first case gives me less events compare to the second one. It seems very strange for me. I would expect that by adding new algorithms I should be getting less rather then more events.

Why? If you multiply your initial pdf with another pdf, you will obtain a different probability distribution. I cannot see a direct correlation of drop in efficiency with increasing number of algorithms.

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Why? If you multiply your initial pdf with another pdf, you will obtain a different probability distribution. I cannot see a direct correlation of

Sorry may be I was not clear. It is exactly what I would expect but for some reason my results are opposite. Efficiency goes up with increasing number of algorithms.

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Quote: |

... theAnalysis->FillList( looseElectrons, "ElectronLoose", "PidAlgoEmcBayes;PidAlgoDrc;PidAlgoMvd"); In this case the probabilities for PID selection are achieved by multiplying the probability values of the chosen algorithms, i.e. Pe = Pe,1 × Pe,2 × Pe,3, etc. |

The only case one can get increase in efficiency is if one of the probabilities >1 what is impossible. Am I right?]]>

If the denominator goes down, the probability can increase.]]>

In other words: when you increase the probability of a particle being a proton the other probabilities will drop accordingly.

You should also be really careful which PID you want to include for which particle species. Soem detectors might introduce unnecessary mix-ups. Always crosscheck with MC information to be safe.

Cheers, Ralf.]]>