1. Status of Sirene Maarten de Jong

2. What?  Sirene is a program that simulates the detector response to muons and showers  It is based on the formalism of the probability density function (PDF) of the arrival time of light (ANTARES-SOFT-2010-002)  It uses the muon energy loss cross sections by P. Kooijman

3. Why?  Sirene makes it possible to quantify the effects of various approximations, limitations, etc. – compare input to input before running Monte Carlo pre-study of water properties, PMT characteristics, etc. – compare input to output e.g. pseudo experiments – compare output to output test of various codes (km3, HOURS, clsim,...)  Implements flexibility by design – it uses the collections framework that is part of the Jpp/JTools package (see ANTARES-SOFT-2011-003) any number of bins and dimensions (limited only by RAM) different interpolation methods (spline, polynome,...)

4. Status Formalism for light production, propagation and detection ‒PDFs based on single scattering approximation from Jpp/JPhysics package (see ANTARES-SOFT-2011-004) Muon propagation – Bremmstrahlung(threshold 10 MeV) – pair production(threshold100 MeV) – photo-nuclear interactions missing ( ~ 20% effect) – [multiple] scattering of muon missing One particle approximation for all other particles from primary vertex ‒simulation of direct and scattered light

5. Procedure 1.Make PDF tables≤2.5hours – accuracy determined by number of points, not by statistics – verification of interpolated arrival times (point/point) 2.Convert PDFs to CDFs<1min. ‒verification of generated arrival times (distributions) 3.Run event processor – detector geometry from.det file – setup radiation tables (to speed up determination of cross section and shower energy for pair production) – I/O ROOT formatted.evt file

6. Pseudo experiments ‒ ANTARES-SOFT-2011-005 ‒ KM3NeT internal note

7. R [m]E m [TeV]PMT A1A1 250.1East A2A2 250.1West A3A3 500.1East A4A4 500.1West B1B1 251East B2B2 251West B3B3 501East B4B4 501West C1C1 2510East C2C2 2510West C3C3 5010East C4C4 5010West muon R West East photon z = -100 m “Experimental setups”

8. E  = 0.1 TeV  t [ns] R = 50 m WestEast R = 25 m A1A1 A2A2 A3A3 A4A4 PDF Sirene

9. E  = 1 TeV WestEast R = 50 m R = 25 m  t [ns] B1B1 B3B3 B2B2 B4B4 PDF Sirene

10. E  = 10 TeV  t [ns] R = 50 m R = 25 m WestEast C1C1 C3C3 C2C2 C4C4 PDF Sirene

11. Standard Monte Carlo production “km3 + geasim”

12. Processing steps ¶ 1.Read Event from MonteCarloEventWriter output file 2.Remove existing hits 3.Propagate muon(s) ‒simulate energy loss and EM-showers ‒generate hits (direct and single scattered light) 4.Process shower particles from primary vertex ‒generate hits (direct and single scattered light) 5.Merge hits (to speed-up TriggerEfficiency) ‒  T max typically 15 ps 6.Write Event to MonteCarloEventWriter compatible output file ¶ Elapsed time steps 1 ‒ 6 ≤ 15 min. per file with about 36,000 events

13. E [GeV] Antares trigger effective volume Volume [m 3 ] km3 Sirene ± 20% Ratio

14. Muon light yield  t [ns] number of events [a.u] direct scattered km3 Sirene

15. EM-shower light yield  t [ns] direct scattered number of events [a.u] km3 Sirene

16. Performance E [GeV] time [ms] ¶ Events with ≥ 1 hits Average time per event ¶

17. Summary & Outlook  Sirene is a program that simulates detector response to muons and showers ‒it is ready for use by Antares ‒for use in KM3NeT needs some additional work  PDFs are reproduced reasonably well in pseudo experiments ‒missing photo-nuclear cross section could explain (small) differences  Functionality is equivalent to “km3 + geasim” ‒trigger effective volume is similar ‒distributions of arrival times are different

18. Summary & Outlook (II)  Possible improvements – include photo-nuclear cross sections – include [multiple] scattering of muon – customize for multi-PMT optical module – interface with existing Sirene software