From the simulation to the reconstruction: The FEDRA-MC interface

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

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

5. y x z OpRootBRICK OpRootBRICK vs OpRoot • Changes to the source code: (new AliGenBox.cpp and AliGenBox.h) • it is possible to choose the Px/Pz and Py/Pz instead of  and ; • 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

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

7. acceptance window YES YES YES YES NO NO NO NO ORFEO = + from the microtracks to the FEDRA input microtracks pulse height affine transf. • a11, a22 gaussian: m=1.,  =0.01; • a12, a21 gaussian: m=0.,  =0.01; • b1, b2 gaussian: m=0.,  =1000.; Gaussian pulse height Poissonian pulse height Data parametrization smearing efficiencies • x, y gaussian smearing: • mean=0. m • sigma=0.5 m • Tx, Ty gaussian smearing: • mean=0. Rad • sigma=0.013 rad micro track rejection based on data efficiencies parametrization FEDRA

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);