1. TRANSMISSION LENGTH STATUS HAROLD YEPES-RAMIREZ IFIC, January 12 th 2010 1

2. 2 OUTLINE CURRENT ANALYSIS: 1. 40 K sensitivities computation status. 2.Status of data taking. Discussion. 3.General ANTARES MC: preliminary study on different MC productions based on optical properties parameters from real data (absorption length inputs and water models). 4.Wikipage on optical calibration status. PROSPECTS TO CM CERN FEBRUARY 2011: 1.Talk in the calibration session  Transmission length measurements: a “multi-wavelength” analysis from the OB data. 2.Talk in the MC session  Impact of water optical properties on reconstruction: from OB data to MC. A preliminary study.

3. 1. 40 K sensitivities computation status: It is not the topic of the Roland Ritcher (ECAP) work. Based on the Dmitry’s 40 K sensitivities computations, my own procedure has the following steps (crosschecks with a sample files specially designed for me by Dmitry): 1.First step (2 sub-steps): build K40 coincidence histograms for each run and pair of OMs/ARSs (k40.cc); compute event rates and dead time (XOFF/HRV) corrections (rate.cc). 2.Second step: fit each of the K40 histograms and apply the dead time corrections (ProcessK40Run.C). 3.Third step: human supervision. If series of 3 or 4 from a set of 7 runs are selected, choose which of them are the best ones (runs taken the same day, low background and consistent among them). 4.Fourth step: run a sensitivity computation script for each of the selected run series (fitK40.C), it's actually integrated into "ProcessK40Run.C". This step can be "avoided". 5.Fifth step: computations of OM efficiencies based on the measured K40 coincidence rates (OMEfficiency.C). The output is a ntuple which arrays sensitivities by OM’s and lines. A simple perl script with an editable txt file with the physics runs (enough size, low BK) to be used for sensitivities, performs all steps in one single step, without human supevision. My own sensitivities have been applied since 23/11/2010. CURRENT ANALYSIS

4. 2.Status of data taking. Discussion: 2.1 JP Ernenwein comments: Once again, the time spent in calibration is questioned. A new policy of data taking should be implemented (my own sense). My suggestion is based on: Lots of runs for some beacons (L2F2, L12F2) which confirm the measurement they give. The need of more statistics with other beacons (…). Reproducibility of measurements with the new Multi-Wavelength beacon (L6F2), in fact, it includes measurements in the UV-Blue region. Medium (MI) and low intensity (LI) measurements have been forgotten. The 6 measurements at LI shows a distribution more centered in 60 m than the other ones at different intensities (overall at high intensity). Medium intensity shows a transmission length value much higher than the one measured at high intensity  Systematics in MC? Interest on L Vs Intensity (L Vs Voltage, Vs Voltage) and L Vs Depth (F15 LI) plots.

5. 5 (varias caras) TO BE UPDATED !!!

6. 2.2 X-mas beacon news: Only TOP LEDs seem to be working. Measurements with group FOUR, MIDDLE for face 4; NO EVENTS, EMPTY, seem not to be working. Face 4: Only measurements with group TOP (not “cleaved” LED). Measurements with other faces scheduled…(it could be today, higher rates). Real equivalence between Voltage Vs Wavelength. 1 2 3 4 5 6

7. 7 3.General ANTARES MC STATUS: The KM3MC package: Simulation of the response of ANTARES to the passage of high energy .  5 tables are mandatory to perform the KM3MC simulations: One table for muons with E = 100 GeV. Five tables for electrons with E = 0.1, 1.0, 10, 100 GeV. 1.GEN 2.HIT Water model. Photon tables production (water tables) for a single of 2 m length using GEANT4. Water tables (hbook files). Tables description (ASCII files). OM parameters. Hit probability computation from the water tables for a given OM parameters. Hit tables (hbook files). Tables description (ASCII files). To HIT To KM3 3.KM3MC Simulated events: Geometry + Kinematics Physics events reading and OM hits production based on event geometry and hit probability tables. Detector events: Signal hits, physical background.

8. 8 After KM3MC steps... Reconstruction of tracks direction(AAfit) + ntuples information arrangement: number of hits, zenith distribution…(AntDST) DONE! Final stage Translating ASCII to ROOT: KM3 output files are translated into ROOT file format. 4. MonteCarloEventWriter 5.TriggerEfficiency Electronics smearing + optical background: calibration, ARS response, noise distributions.

9. Cos  c Angular aceptance Available sets of water tables: At date, 3 different sets of water tables have been created for analysis: 1)Angular acceptance June 2009 (Heide Costantini, CM Genova) and absorption length 63 m at 470 nm: /sps/km3net/users/margiott/km3_tab_antares/km3_v3r7/tab_jun09_abs6 3_reproc/tab 2)Angular acceptance June 2009 and absorption length 60 m at 470 nm: /sps/km3net/users/margiott/km3_tab_antares/km3_v3r7/tab_jun09_repr oc/tab 3)Standard angular acceptance (December 2008) and absorption length 55 m at 470 nm: $GROUP_DIR/km3/hbook In addition, two special MC productions which use PARTIC (0.01, 0.02) and MEDSEA (0.0075, 0.01, 0.02) models with absorption Length 55 m at 470 nm and angular acceptance December 2008: /sps/km3net/users/margiott/scatt_model  Drawbacks at TriggerEfficiency level (Checking!!!)

10. 10 Fit Quality (one plot, one run) for atmospheric muons (any cut applied): L abs =55 mL abs =60 m L abs =63 m

11. 11 Zenith distribution (one plot, one run) for atmospheric muons (any cut applied): L abs =55 m L abs =60 m L abs =63 m

12. 12 Other plots to draw…

13. 13 To review!!!!! (some cross-checks with JP done) To review in these plots (however all of them were performed under the same conditions): Cuts used in reconstruction. TriggerEfficiency parameters. Angular acceptance influence. Software versions. Complete check-up of all AntDST analysis tools  More plots well explained and new ones soon. A well understanding of the parameters used throughout the reconstruction stages. Analysis of the full sample of MC production  100 runs for Labs=55m, 100 runs for Labs=60 and 100 runs for Labs=63. A deep cross-checks at TriggerEfficiency level for the special production of MEDSEA and PARTIC with different scattering centres. To define which could be “the best” optical parameters from the OB data, for a future MC production (at least a slight proposal).

14. 14 4.WikiPage on optical calibration: http://antares.in2p3.fr/internal/dokuwiki/doku.php?id=calibration To be completed !!! (around 80 % filled). Suggestions are welcome!

15. 1.Talk in the calibration session  Transmission length measurements: a “multi-wavelength” analysis from the OB data. Experimental procedure: brief description. Influence of applied voltage on wavelength. Way to pulse the OB. We have started our 40 K calibration. Results on Wikipage. Comparisons with NESTOR paper...is it the moment to write a brief NIM paper or internal note? 2.Talk in the MC session  Impact of water optical properties on reconstruction: from OB data to MC. A preliminary study. Motivation to perform the study: hits from the OB data. Brief reminder of light propagation in sea water. MC stages description: KM3 package + analysis tools. Description of inputs: optical parameters, noise files, angular acceptance, ARS thresholds, software versions... Analysis of nTuples data from AntDST for all MC productions. PROSPECTS TO CM CERN FEBRUARY 2011

16. Next steps: test on data, data/MC comparison, other cuts... Suggestion to proceed. PROSPECTS TO CM CERN FEBRUARY 2011