1. IMPACT OF WATER OPTICAL PROPERTIES ON TRACKS RECONSTRUCTION H Yepes -Ramirez IFIC (CSIC – Universitat de València) ANTARES Collaboration Meeting Moscow, June 06 th -10 th, 2011

2. OUTLINEOUTLINE ANTARES Collaboration Meeting Moscow, June 06 th -10 th 2 Brief reminder of light propagation in sea water: Brief reminder of light propagation in sea water: ANTARES Monte Carlo model Simulation: Simulation: absorption and scattering inputs, codes and data selection Selected results Conclusions and outlook Brief reminder of light propagation in sea water: Brief reminder of light propagation in sea water: ANTARES Monte Carlo model Simulation: Simulation: absorption and scattering inputs, codes and data selection Selected results Conclusions and outlook

3. Brief reminder of light propagation in sea water ANTARES Collaboration Meeting Moscow, June 06 th -10 th 3 Scattering phase function (  ) Morel and Loisel approach  Molecular scattering ( Rayleigh )  Isotropic ( =0)  = contribution of Rayleigh scattering  Particle scattering ( Mie )  Strong forward peaked ( Mie =0.924) Attenuation Length (COLIMATED BEAM) Effective Attenuation Length (ISOTROPIC SOURCE) Absorption length Scattering Length Scattering length wavelength dependence (Kopelevich parameterization) b = scattering coefficient. v s, v l = scattering centers. = Average cosine of the global distribution Petzold values for particle scattering

4. SimulationSimulation ANTARES Collaboration Meeting Moscow, June 06 th -10 th 4 A set of water properties inputs reliable for study: AIM  production of the absorption and scattering spectrum for different water models for muons and neutrinos, in agreement to the water models proposed for the data/MC CALIBOB comparison for optical beacon data (J Ruiz-Rivas, Collaboration Meeting in Paris 2010). Ten different water models (two runs each, just for a first approach) for muons and neutrinos (20 files for muons, 20 files for neutrinos).

5. SimulationSimulation ANTARES Collaboration Meeting Moscow, June 06 th -10 th 5 abs [m] V s, V l (scattering centers) [ppm] scat at 470 nm [m]  550.0075530.17 550.01410.17 550.02220.17 550.01410.11 550.02220.02 630.0075530.17 630.01410.17 630.02220.17 630.01410.11 630.02220.02 Three runs with the same  value and different scattering spectrum for a given absorption length. Three runs with different  values, but  is computed in such a way that the three runs will have the same effective scattering length at 470 nm, for a given absorption length. Three common models for comparisons (muons abs55-abs63, neutrinos abs55) with previous Monte Carlo productions. OM Angular acceptance of June 2009 (Genova Meeting 2009).

6. SimulationSimulation ANTARES Collaboration Meeting Moscow, June 06 th -10 th 6 GEN WATER MODEL: Photon tables production (water tables)  Water tables (hbook files) + Description files (ASCII files). HIT OM PARAMETERS: Hit probability computation from the water tables for a given OM parameters  Hit tables (hbook files) + Description files (ASCII files). KM3 SIMULATED EVENTS: GEOMETRY + KINEMATICS Physics events reading and OM hits production based on event geometry and hit probability tables  Detector events: Signal hits (muons, not tracks from hadronic showers), physical background. GEASIM MCEW TE RECO SIMULATIONS OF ATMOSPHERIC NEUTRINO INTERACTIONS. Process (and evaluation) tracks from particles coming from the hadronic showers (also muons from KM3). TRANSLATION OF INFO ASCII FILES INTO ROOT FORMAT. FORMAT CONVERSION TO “LOOK LIKE DATA”: electronics smearing effects (calibration, ARS response) and optical background. RECONSTRUCTION: Reconstruction of track direction (AAfit) and ntuples information arrangement as number of hits, zenith distribution…(AntDST). Simulation chain:

7. SimulationSimulation ANTARES Collaboration Meeting Moscow, June 06 th -10 th 7 Main options and software versions in muons and neutrinos simulation: CODE/INPUTOPTIONS/VERSIONS GENv3r7 HITv3r7 KM3v3r7 DETECTORr12_c00_s01 GEASIMv4r10 MCEW- TriggerEfficiencyGaussian ARS threshold file: threshold_gaus_0.33_0.08_0.1.txt SoS file: noise_basic_harold.root (Thanks to C Bogazzi) -n 10000000 –t 104.858 –C3 – p 0.035 -t 104.858  Frame time in ms. To determine the number of background hits to be generated in case the summary data are used. -C3  Hit generator type: 3, Gaussian, according observed charge distribution, with time-dependent contribution of after pulses. 2010-09-23 version Aafitv0r6 AntDSTv1r1

8. SimulationSimulation ANTARES Collaboration Meeting Moscow, June 06 th -10 th 8 Methodology: runs selection, lifetime computations and weights 1.Data subsample: “Point source search with 2007 and 2008 data” ( ANTARES-PHYS-2010-008 ). 3.Lifetime and scaling for MC: Lifetime for neutrinos: 365 days. Lifetime for muons: 2*8320/86400 = 0.19 days. 4.Weights: Neutrinos: w3*(1.0/2*1.0e+10). 1044 files (12 lines detector) [08/05/2008-30/12/2008]. Lifetime data: 76.77 days. ntuples from JP Gomez-Gonzales (thanks!!!). 2.MC sampling: SoS file prepared by C Bogazzi (thanks!!!) from the data subsample (noise_basic_harold.root): time slices taken from all different acquisition conditions. Mupage for muons. Geasim for neutrinos.  Thanks to Annarita and Carla also for the codes used as starting point and their support !!!  Thanks also to Patrick, Maarten and Aart from NIKHEF for their appropriate help about software details !!!

9. “Different” water tables – Same SoS file “Different” water tables – Different SoS file Same water tables – Same SoS file Remarks: 1.Water tables produced by Annarita to Juan Pablo and the mine ones, are equivalent (absorption length 63 m). 2.Reproducibility of the simulation chain and equivalence among scripts are OK (just one run considered). 3.Run-dependent simulation effect is seen from the SoS Monte Carlo sampling (factor ~ 1.20). 4.Agreement data / MC should be independent of the SoS file. Confirmation in next slides  MC Sampling with a SoS file based on 2008-2009 data subsample. Data/MC comparisons with the same data subsample. SimulationSimulation ANTARES Collaboration Meeting Moscow, June 06 th -10 th 9

10. SimulationSimulation 10 My production ( abs = 55 m) Juan Pablo (Amsterdam) ( abs = 55 m) SoS File: noise_basic_harold.root Data ≈ MC (  ), Data > MC ( ). KM3 v3r7, Aafit v0r6. 2008 data. OM angular acceptance 09. SoS File: ? Data < MC (  ), Data ≈ MC ( ). KM3 v3r6, Aafit v0r6. 2007-2008 data. OM angular acceptance 08. tcosth > 0 && beta < 1

11. Juan Pablo (CERN) RED: abs = 63 m SimulationSimulation ANTARES Collaboration Meeting Moscow, June 06 th -10 th 11 My production RED: abs = 63 m SoS File: noise_basic_harold.root MC > data. Aafit v0r6. SoS File: noiseblendL12-basic.root Data > MC. Aafit v0r6. tcosth > 0 && beta < 1

12. SimulationSimulation ANTARES Collaboration Meeting Moscow, June 06 th -10 th 12 What kind of information we have: 1.Reconstructed data (muons + neutrinos): Absorption + scattering info: Reconstruction quality parameter. Number of hits used in the fit. Total amplitude of the hits used in the fit. Zenith distributions. Etc…(backup). Scattering info  Time residuals. 2.No reconstructed data has not been analyzed yet. A quick look over some distributions      

13. Some extremes models could be discarded (i.e, blue line). Muons region seems to be specially in agreement for the cases at the same effective scattering length (lambda > -7). Neutrinos region for lambda > -4.5 have a nice agreement. MC Underestimation lambda < -4.5. ResultsResults ANTARES Collaboration Meeting Moscow, June 06 th -10 th 13 Reconstruction quality parameter (  ): tcosth > 0 && beta < 1

14. Some extremes models could be discarded (i.e, grey line). Muons region seems to be in agreement most cases. Neutrinos region agreement at absorption 55 m is not enough clear as is seen for the models at 63 m. And peaks..? ResultsResults ANTARES Collaboration Meeting Moscow, June 06 th -10 th 14 tcosth > 0 && beta < 1

15. Some extremes models could be discarded (i.e, blue line). Some distributions scales to the peak and others to the tail… ResultsResults ANTARES Collaboration Meeting Moscow, June 06 th -10 th 15 Number of hits used in the fit (N hit ): tcosth 5 && lambda > -5.4

16. Some extremes models could be discarded (i.e, blue line). Scale to the peak is not seen as in the previous case, but a nice agreement seems to be for the tails of the green and light blue model. ResultsResults ANTARES Collaboration Meeting Moscow, June 06 th -10 th 16 tcosth 5 && lambda > -5.4

17. Some extremes models could be discarded (i.e, blue line). Some distributions scales to the peak (blue and magenta) and others to the tail (green and sky blue). ResultsResults ANTARES Collaboration Meeting Moscow, June 06 th -10 th 17 Total amplitude of the hits used in the fit (A hit ): tcosth 5 && lambda > -5.4

18. ResultsResults ANTARES Collaboration Meeting Moscow, June 06 th -10 th 18 Some extremes models could be discarded (i.e, blue line). Agreement to the tails for green and sky blue models, seems to be for light yellow also. tcosth 5 && lambda > -5.4

19. Some extremes models could be discarded (i.e, blue line). Peaks ??? Muons region agreement could be take place for distributions at same effective scattering length. Lack of neutrino events for most cases  STATISTICS DEPENDENT (few runs to compare)  SEE NEXT SLIDE. ResultsResults ANTARES Collaboration Meeting Moscow, June 06 th -10 th 19 Zenith angle of the fitted track (cos  ): lambda > -5.4 && beta < 1

20. ResultsResults ANTARES Collaboration Meeting Moscow, June 06 th -10 th 20 Statistics effect on zenith distributions: abs = 55 m @ 470 nm (from official productions)

21. Some extremes models could be discarded (i.e, grey line). Peaks ??? Muons region agreement could be take place for distributions at same effective scattering length. Lack of neutrino events again !!! ResultsResults ANTARES Collaboration Meeting Moscow, June 06 th -10 th 21 lambda > -5.4 && beta < 1

22. ResultsResults ANTARES Collaboration Meeting Moscow, June 06 th -10 th 22 Time residuals (t hit - t exp ):

23. ResultsResults ANTARES Collaboration Meeting Moscow, June 06 th -10 th 23

24. CONCLUSIONS AND OUTLOOK ANTARES Collaboration Meeting Moscow, June 06 th -10 th 24 1.How much the correct model could matters? 2.What model could we trust on it? 3.P 4.L 5.A tentative “to do list”: Number of hits in the trigger. Total number of hits in the event. Arrival time of the hit on the PMT, before and after trigger. Detector performance: expect impact on effective areas and detector angular resolution. MORE PLOTS CAN BE FOUND IN THE BACKUP OR: http://ific.uv.es/~yepes/CM_MOSCOW_2011/finalPlots 1.How much the correct model could matters? 2.What model could we trust on it? 3.P 4.L 5.A tentative “to do list”: Number of hits in the trigger. Total number of hits in the event. Arrival time of the hit on the PMT, before and after trigger. Detector performance: expect impact on effective areas and detector angular resolution. MORE PLOTS CAN BE FOUND IN THE BACKUP OR: http://ific.uv.es/~yepes/CM_MOSCOW_2011/finalPlots

25. BACKUPBACKUP ANTARES Collaboration Meeting Moscow, June 06 th -10 th 25 5 parameters fit -  2 minimization: t 0, , , x 0, y 0 Reconstruction quality factor L: Linear prefit photon hit coordinates x, y, z, t Minimization with hit-charge weights. Maximum likelihood (L) fit computed from MC PDF of time residuals.

26. BACKUPBACKUP ANTARES Collaboration Meeting Moscow, June 06 th -10 th 26 Statistics effect on zenith distributions: abs = 63 m @ 470 nm (official mupage production @ CERN)

27. BACKUPBACKUP ANTARES Collaboration Meeting Moscow, June 06 th -10 th 27 Angular error (  ):

28. BACKUPBACKUP ANTARES Collaboration Meeting Moscow, June 06 th -10 th 28

29. BACKUPBACKUP ANTARES Collaboration Meeting Moscow, June 06 th -10 th 29 Azimuth:

30. BACKUPBACKUP ANTARES Collaboration Meeting Moscow, June 06 th -10 th 30

31. BACKUPBACKUP ANTARES Collaboration Meeting Moscow, June 06 th -10 th 31 Number of lines used in the fit (N lines ):

32. BACKUPBACKUP ANTARES Collaboration Meeting Moscow, June 06 th -10 th 32

33. BACKUPBACKUP ANTARES Collaboration Meeting Moscow, June 06 th -10 th 33 GLOSARY: Time slices: