How to propagate a track to the IP and to the calorimeter surface

[andread3vita]

Hi all,
I am working with genfit to fit CLD tracks and I managed to create edm4hep::Tracks with two TrackStates: at first and last hit. In ILCsoft, I know that the trackState IP is calculated by propagating the track on an additional surface within the beam pipe. I wonder if it is possible to do the same with an edm4hep::Track with only two trackStates defined.

Thank you!

Andrea

[andresailer]

Hi @andread3vita

What do you have? Do you have the track with the trackstates and the hits? Or do you just have the trackstates? And do you want to do the propagation with genfit, or with iLCSoft tracking?

[andread3vita]

Hi @andresailer
Here is what I am doing:

• given an edm4hep::Track, I fit it with genfit;
• given the output of the fit, I create another edm4hep::Track (internal_track) with all the hits and I create also the trackstates at the first and at the last hits:

edm4hep::TrackState trackStateFirstHit;
trackStateFirstHit.D0 = d0;
trackStateFirstHit.Z0 = z0;
trackStateFirstHit.phi = phi0;
trackStateFirstHit.omega = omega;
trackStateFirstHit.tanLambda = tanLambda;
trackStateFirstHit.time = time;
trackStateFirstHit.covMatrix = covMat;
trackStateFirstHit.referencePoint = edm4hep::Vector3f(pos[0], pos[1], pos[2]);
trackStateFirstHit.location = edm4hep::TrackState::AtFirstHit;

edm4hep::TrackState trackStateLastHit;
//definition of trackStateLastHit parameters

internal_track.addToTrackStates(trackStateFirstHit);
internal_track.addToTrackStates(trackStateLastHit);

What I would like to do is to propagate internal_track with iLCSoft.

[andresailer]

Hi @andread3vita

So what exactly is the problem you are having with propagating the track?

[andread3vita]

I am writing a track fitter based on genfit and what I get is a genfit::Track with the status of the fit attached to each hit. For this reason, if I convert this track to an edm4hep::Track, I can only create two trackStates.

My temporary solution is to use the built-in propagator of genfit for the IP and the method developed in this file for the calorimeter. Is there a method from iLCSoft to do that within a gaudi::functional?