GSI Forum
GSI Helmholtzzentrum für Schwerionenforschung

Home » PANDA » PandaRoot » Analysis » Vertex Fitter in Fast simulation
Re: Vertex Fitter in Fast simulation [message #16379 is a reply to message #16125] Sun, 20 April 2014 08:35 Go to previous messageGo to previous message
Klaus Götzen is currently offline  Klaus Götzen
Messages: 293
Registered: June 2006
Location: GSI
first-grade participant
From: *dip0.t-ipconnect.de
Hi,


thinking a bit more about the approach of setting dE = dp for neutrals, there is some problem with the way it is done now I think.

Since E and p are 100% correlated quantities, the covariance cannot be diagonal if you set both at the same time. That has to be taken into account right from the beginning. However when the smearing is techincally done in Fast Sim, it is in an uncorrelated way, so that E and p get an individual random modification.

I guess, a proper way would be for neutrals:

- Just set the dE in the detector classes.

- Chose a random smearing base on this dE value.

- Smear both E and p with this value.

- Set the according diagonal elemens for E and p and the correlated term sigma_E,p in covariance matrix before transformation to px, py, pz, E domain.

I'm not really sure whether this is the right way, but one could at least try like this.


Best and happy easter,
Klaus

 
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Previous Topic: [FIXED] Error in <PndAnaPidCombiner::Apply>
Next Topic: Lambda Lambdabar simulations
Goto Forum:
  


Current Time: Tue Oct 22 10:34:47 CEST 2019

Total time taken to generate the page: 0.02877 seconds