1. From the simulation to the reconstruction: The FEDRA-MC interface Alberto Marotta University FEDERICO II & INFN - Napoli OPERA CERN, April 2004

2. Outline The main goal: an interface between the MC and FEDRA Status of the work: a first phase is completed and a tool is ready to produce simulated events, in the FEDRA input format at “base tracks level“, to test algorithms and simulate test beam Next step: an upgrade of the code to produce the FEDRA input format at “micro tracks level”

3. software chain OpNtuple ntuple MyAna root ASCII NEGN/Jetta OpRoot OpTreeConvert OpDigit OpRec micro tracks with smearing fedra MyBrick OpRoot to FEdra cOnverter OpRootBRICK OpRoot hits emulsion digits micro tracks

4. software chain Reconstruction software OpRoot to FEdra cOnverter NEGN/Jetta OpRoot OpTreeConvert OpDigit emulsion digits micro tracks with smearing electronic detectors digits Real Data & MC Data Storage

5. OpRootBRICK OpRootBRICK vs OpRoot Changes to the source code: (new AliGenBox.cpp and AliGenBox.h) 1. it is possible to choose the Px/Pz and Py/Pz instead of and  ; 2. it is possible to select exactly the impact surface of the beam on the brick. It is implemented the geometry of a 1-brick detector. (a new directory work to be added) The new AliGenBox.* files can be changed in the official code and the new work directory can be added without any conflict with the official OpRoot release z x y

6. TreeH: Header Event Number nVtx nTrack nPrimary Vert_Number Vert[3] nOut OutPdg[nOut] TreeM: Micro Track Event Layer PdgId Track X Y Z Dz Tx Ty P dE MyBrick output: microtracks

7. from the microtracks to the FEDRA input microtracks FEDRA smearing affine transf. pulse height x, y gaussian smearing: mean=0.  m sigma=0.5  m Tx, Ty gaussian smearing: mean=0. Rad sigma=0.013 rad a 11, a 22 gaussian: m=1.,  =0.01; a 12, a 21 gaussian: m=0.,  =0.01; b 1, b 2 gaussian: m=0.,  =1000.; NO YES acceptance window 1. Gaussian pulse height 2. Poissonian pulse height 3. Data parametrization x1x1 a 11 a 12 xb1b1 y1y1 a 21 a 22 yb2b2 NO YES NO YES ORFEO = + NO YES efficiencies micro track rejection based on data efficiencies parametrization

8. Outlook micro tracks and base tracks are simulated with: smearing, pulse height, affine trasformation, efficiency NEXT STEPS FEDRA input format for FEDRA at “micro tracks level“ Simulate instrumental background. Idea: use Max program to generate fog grains and Sysal to reconstruct micro tracks. Then superimpose them to the MC truth Produce an output that combines electronic and emulsion reconstruction information

10. The simulated FEDRA input Tree s, s1, s2: x, y, z; Tx, Ty; DZ (emulsion width); P; dE; Aid[2] Aid[0]=Event Number, Aid[1]=Geant Track Number, W (pulse height); FLAG (PdgId);