1. Reconstruction code and comparison between Genie and Genhen A. Trovato, C. Distefano, R. Coniglione and P. Sapienza Kick-off ORCA meeting: 6 September 2012, APC Paris 0

2. Reconstruction code and comparison between Genie and Genhen A. Trovato, C. Distefano, R. Coniglione and P. Sapienza Kick-off ORCA meeting: 6 September 2012, APC Paris 1

3. Overview 2 Description of the reconstruction code Attempt to use this code in the low energy region for different detector configurations Description of Genie (Carla Distefano work) Comparison between Genie and Genhen (Carla Distefano work)

4. Simulation Kick-off ORCA meeting: 6 September 2012, APC Paris 3 PackageVersion Genhenv6r10 Km3v3r7 geasimv4r10 modk40v4r10 RecoSee Next Slides Waters & PMT characteristics from WPD document Codes from Antares modified for multi-PMT by Rosa Coniglione Detector 1 - ORCA  61 lines with 20 storeys each  6 m vertical spacing  25 m line separation Detector 2  61 lines with 20 storeys each  40 m vertical spacing  100 m line separation

5. Reconstruction code Original “AartStrategy” reconstruction algorithm modified to exploit the multi-PMT peculiarities Kick-off ORCA meeting: 6 September 2012, APC Paris 4 Trigger based on coincidence between PMT on the same OM. First study on coincidence between neighboring OM on the same line Dependence on the hit amplitude neglected. Instead, each hit have a “score” depending on the kind of coincidence Angular Selection: hit accepted in a given PMT field of view (cosθ< −0.5, whereθis the angle between the incident photon from a starting track and the axis of the PMT) track photon PMT axis -θ Code optimized for E = 1 – 100 TeV

6. Reconstruction scheme Kick-off ORCA meeting: 6 September 2012, APC Paris 5 All hits Selected hitsPrefit hits Merged hits M-estim. hits pdf hits Final pdf hits Linear prefit Angular Selection Generate start tracks Angular Selection + Time Residual M-estimator fit Pdf fit Best track Final fit Linear prefit For each track: Angular Selection + Time Residual Angular Selection + Time Residual

7. Effective area and volume Kick-off ORCA meeting: 6 September 2012, APC Paris 6 The number of events depends on the neutrino effective area: where Nucleon per unit of volume Cross section Neutrino transmission probability in the Earth

8. Effective volume Kick-off ORCA meeting: 6 September 2012, APC Paris 7 Effective volume calculated for upgoing events with the vertex inside the can Instrumented volume = 1.9 x 10 5 m 3

9. Effective volume Kick-off ORCA meeting: 6 September 2012, APC Paris 8 Effective volume calculated for upgoing events with the vertex inside the can Instrumented volume = 1.9 x 10 5 m 3 Instrumented volume = 2 x 10 7 m 3

10. Effective area and angular error Kick-off ORCA meeting: 6 September 2012, APC Paris 9

11. Effective area and angular error Kick-off ORCA meeting: 6 September 2012, APC Paris 10 Quality cut added

12. End of the first part Kick-off ORCA meeting: 6 September 2012, APC Paris 11

13. gSeaGen: a GENIE based code for neutrino telescope Carla Distefano 12

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16. Why GENIE for neutrino telescope? migration to C++  use of modern neutrino interaction codes continually maintained used by experiments at different energy ranges  data comparison 15

17. gSeaGen: a GENIE based neutrino generation code Main code: gSeaNuEvGen Libraries: GSeaAtmoFluxflux driver: generation of neutrinos GSeaRealAtmoFluxflux driver: definition of the physical flux GSeaGeometrygeometry driver: building of the interaction volume EvtWrite class: writing of the evt output file (same tags in GenHen) Code organization: 16

18. The main code: gSeaNuEvGen gSeaNuEvGen Reading of the.det geometry file to define the detector CAN Generation of electron and muon flavours Generation of neutrinos and anti-neutrinos at the same time (e.g. ν μ + anti-ν μ ) Simulation of CC, NC but also CC+NC For muons: propagation still done with Music but now the code is linked with PropMusic* Spectrum binned in equal divisions in Log10(E ν ): - Probabilities are scaled-up at each bin (P scale ) -> higher stat. at low energy - For muons: scaled volumes and number of events (GenHen approach) Same output of GenHen (class EvtWrite linked to Antares io library) * In GENIE: the MuELoss utility package that computes muon energy losses in the energy range from 1 GeV to 10 TeV due to ionization, direct e - e +, pair production, bremsstrahlung and photonuclear interactions and in several material as water and standard rock. 17

19. A first comparison with GenHen Same input: energy and angular range, generation spectral index, physical flux… but: gSeaGen: full simulation of neutrino interaction (probability scale) xsec calculated at neutrino each energy interaction in seawater and rock as defined in the geometry GenHen: all neutrinos interact xsec calculated at the centre of energy bins interaction with iso-scalar nuclei in water equivalent media 18 The code takes a time a factor 10 larger than GenHen (due to the full simulation); The difference will increase at high energy and for a larger detector; We’ll consider the possibility to implement a fast simulation mode (GenHen approach). Input: Detector: ANTARES Energy range: 10 – 500 GeV (α=-1.4) Up- and Down-going events, flat in solid angle Nbin = 10 Neutrinos and anti-neutrinos Physical flux: Bartol

20. A first comparison with GenHen

21. Backup Slides Kick-off ORCA meeting: 6 September 2012, APC Paris 20

22. Kick-off ORCA meeting: 6 September 2012, APC Paris 21

23. Flux Drivers: GSeaAtmoFlux and GSeaRealAtmoFlux For each generated direction (θ,φ), the flux generation surface is a circular area, with radius R T, which is tangent to a sphere of radius R L centred at the coordinate system origin R T and R L are computed by GSeaGeometry as R T = 2R. sinΘ (with tanΘ =H/2R);R L = D where H, R and D are respectively the height, radius and diagonal of the interaction volume R T and R L are set at each energy bin interaction volume Event weight computation Generation weight: Including P Earth in progress (almost done…) Physical flux: Bartol or Fluka fluxes defined using the GSeaReaAltmoFlux driver (where other fluxes could be easily implemented, e.g. prompt neutrinos…) GAtmoFlux 22