CandidateMatchHelpers: Try to transform the cluster calo position vector wrt to (0,0,0) to a position vector wrt to track perigee position

Mentioning @amorley as this tries to tackle of the issues he brough up.

The issue is that for large track r/d0 or z0 one needs to approximate "transform" the position of the cluster from something wrt to (0,0,0) to something wrt track perigee position (x0,y0,z0) before performing the quick and dirty candidate match.

This merge request affects 3 packages:

• Reconstruction/egamma/egammaAlgs
• Reconstruction/egamma/egammaTools
• Reconstruction/egamma/egammaUtils

added Egamma Reconstruction master review-pending-level-1 labels

CI Result SUCCESS

	Athena	AthSimulation
externals
cmake
make
required tests
optional tests

Full details available at NICOS MR-26703-2019-09-20-04-56
Athena: number of compilation errors 0, warnings 0
AthSimulation: number of compilation errors 0, warnings 0
For experts only: Jenkins output [CI-MERGE-REQUEST-CC7 3447]

added review-approved label and removed review-pending-level-1 label

marked as a Work In Progress

changed the description

removed review-approved label

Removing the review-approved label since this is a WIP MR.

yea it is not urgent , but indeed for RPVLL non-pointing large R , we need to change the candidateMatch logic ... If the extrapolation was not a bit slow prb we could just extrapolate but then it will be too many tracks so we need to add a bit more elaborate geometrical cases.

Hi so updating the indent, I can work on it next week prb 1st thing when the cluster here is back up ...

The idea is that perhaps is better/easier for maintenance to do this candidate broad matching in a bit more explicit way. It will be not more efficient but prb easier to understand.

More or less one can make it explicit in translating the cluster calo position from origin at (0,0,0) to (x,y,z) track perigee. And do it for all x,y,z etc.

So perhaps this will be cleaner . In semi-pseudocode

///Get x,y,z of the perigee
Amg::Vector3D XYZOfPerigeeTrack(candidatePerigee.position().x(),candidatePerigee.position().y(), candidatePerigee.position().z());
///Get an approximation of the RClus,Zclus this we can do in the helper which now will reurn a ///Amg::vector3D

................. helper code
CandidateMatchHelper::GetApproxXYZAtlas(....
//===========================================================//
  //These are at the face of the calorimeter
  const  double Rcalo = 1500;
  const  double Zcalo = 3700;
  double Rclus=Rcalo;
  double Zclus=Zcalo;    
  if(clusterEta!=0){
    //eta !=0
    double tanthetaclus=(1/cosh(clusterEta))/tanh(clusterEta); 
    if (isEndCap) {
      Rclus=fabs(Zcalo*(tanthetaclus));
      //Negative Eta ---> negative Z
      if(clusterEta<0){
        Zclus = -Zclus;
      }
    } 	  
    else{
      if(tanthetaclus!=0){
        Zclus=Rcalo/(tanthetaclus);
      }
    }
  }
  else{
    //eta 0
    Zclus=0;
  }

return Amg::Vector3D(Rclus*cos(cluster->phi), Rclus*sin(cluster->phi(),Zclus)
.....................
///Then the above is named like 
 
Amg::Vector3D XYZClusterWrtATLASFrame= CandidateMatchHelper::GetApproxXYZAtlasF(....);
Amg::Vector3D XYZClusterWrtTrackPerigee= XYZClusterWrtATLASFrame-XYZOfPerigeeTrack;

///
/*
Now in principle we can compare the
XYZClusterWrtTrackPerigee->eta(), XYZClusterWrtTrackPerigee->phi() which should be the
cluster eta,phi as viewed from the track perigee with the track eta,phi at that perigee.
We can add the approximate rotation due to the magnetic field as we do 
*/

added 1451 commits

• 5ce15913...9c82ba2c - 1450 commits from branch atlas:master
• 7a749422 - Merge remote-tracking branch 'upstream/master' into CandidateMatchHelpers_add_r_for_correct_eta

Compare with previous version

unmarked as a Work In Progress

resolved all threads

added 1 commit

• 4eaf3644 - Try to transorm cluster calo position vector wrt to (0,0,0) to a position...

Compare with previous version

changed title from CandidateMatchHelpers add r of perigee for broad candidate matching to CandidateMatchHelpers: Try to transorm cluster calo position vector wrt to (0,0,0) to a position vector wrt to track perigee position

changed the description

This merge request affects 3 packages:

• Reconstruction/egamma/egammaAlgs
• Reconstruction/egamma/egammaTools
• Reconstruction/egamma/egammaUtils

added review-pending-level-1 label

This merge request affects 3 packages:

• Reconstruction/egamma/egammaAlgs
• Reconstruction/egamma/egammaTools
• Reconstruction/egamma/egammaUtils

changed title from CandidateMatchHelpers: Try to transorm cluster calo position vector wrt to (0,0,0) to a position vector wrt to track perigee position to CandidateMatchHelpers: Try to transform the cluster calo position vector wrt to (0,0,0) to a position vector wrt to track perigee position

CI Result SUCCESS (hash 4eaf3644)

	Athena	AthSimulation
externals
cmake
make
required tests
optional tests

Full details available on this CI monitor view
Athena: number of compilation errors 0, warnings 0
AthSimulation: number of compilation errors 0, warnings 0
For experts only: Jenkins output [CI-MERGE-REQUEST-CC7 4805]

CI Result SUCCESS (hash 7a749422)

	Athena	AthSimulation
externals
cmake
make
required tests
optional tests

Full details available on this CI monitor view
Athena: number of compilation errors 0, warnings 0
AthSimulation: number of compilation errors 0, warnings 0
For experts only: Jenkins output [CI-MERGE-REQUEST-CC7 4803]

On the face of it looks good to me - i guess we need to check the performance in more detail

Substantial changes across the board, escalating to L2. --L1

added review-pending-level-2 label and removed review-pending-level-1 label

Expert reviewed it and it also looks good to me from the L2 point of view. Approving. Best, -- Ric. (L2)

added review-approved label and removed review-pending-level-2 label

merged

mentioned in commit ff045d2f

added sweep:ignore label

mentioned in merge request !28159 (merged)