|Message: Reconstructing Momenta from a Decay||Not Logged In (login)|
Click on the Forum title, e.g. on the "Forums by Category" page, to read a sequence of postings to the Forum and its threads all in one page. If you are only interested in one thread or the thread following a specific posting, click the thread or the posting, which takes you to a smaller page, which contains only the part you are interested in and may be easier to navigate.
Messages are "chained" if there are only replies at the first level, i.e. 1/1.html, 1/1/1.html etc. In case of "chained" messages the message number is replaced by the icon and there is no indentation.
Inline: Display the subject line only or also the text of the posting(s); for the choice "All" the "Outline" choices are switched off.
|1||0||1||no text / full text of posting|
|2||1||All||text for level 1 only / text for All postings|
Outline: Choose the depth of the posting thread, successive toggle controls provide increasing detail.
|1||2||1||2 levels / 1 level (original posting)|
|2||3||2||3 levels / 2 levels|
|3||3||All||3 levels / all levels (all postings)|
I am currently trying to reconstruct the angle between two outgoing particles from a decay. The decay physics comes from a generator which I wrote myself. In my code, the angle between these two vectors is pulled from a specific angular distribution. The momenta is then set using G4DynamicParticle.
I then retrieve the two outgoing particles in my SteppingAction code and pass them to a function in my EventAction class which reconstructs the angle between the two. Unfortunately, the angular distribution has a tail. It seems that frequently, the angle between the two particles is reconstructed to be smaller than it actually is.
I can think of 3 possible solutions to this problem. 1) I am not accurately identifying the events which I need 2) I am not obtaining the momentum at the vertex of the decay and therefore some scattering is occurring 3) the momentum direction is not defined how I think it is.
I am using the GetVertexMomentum() function in the stepping action to retrieve the momenta at the vertex. My question is, is this momentum defined such that the origin is the world reference frame, or is the origin the decay vertex? What is the proper way to do this?
I have included some histograms for reference. Any help would be much appreciated!
Attachment: http://hypernews.slac.stanford.edu/HyperNews/geant4/get/AUX/2015/04/27/14.37-6072-Psi_Input.png http://hypernews.slac.stanford.edu/HyperNews/geant4/get/AUX/2015/04/27/14.37-52540-Psi_Recon.png http://hypernews.slac.stanford.edu/HyperNews/geant4/get/AUX/2015/04/27/14.37-62932-Possible_Psi_Problem.pdf
|Inline Depth:||Outline Depth:||Add message:|