1. Alexander Kappes Forschungsseminar Institut für Physik, Humboldt-Universität Berlin, 11. February 2011 Fishing for Neutrinos in the Mediterranean Sea – ANTARES and KM3NeT

2. Alexander Kappes, Forschungsseminar, Humboldt-Universität, 11.02.2011c 2 Outline Introduction to neutrino astronomy The ANTARES neutrino telescope Selected results from ANTARES The future Mediterranean neutrino telescope KM3NeT

3. Alexander Kappes, Forschungsseminar, Humboldt-Universität, 11.02.2011c 3 1912: Discovery of Cosmic Rays (Victor Hess) Observations before 1912: -Elektroscopes discharge due to natural radioactivity Balloon experiments since 1912: (Hess, Kolhörster) -Discharge increases above ~1.5 km altitude -Conclusion: Ionising radiation from outer space Measurements Victor Hess (1912)

4. Alexander Kappes, Forschungsseminar, Humboldt-Universität, 11.02.2011c 4 Cosmic rays: spectrum measured over 12 orders of magnitude in energy power law spectrum (non thermal) consists of particles Sources still unknown !... 99 Years Later Cosmic ray spectrum 10 9 10 12 10 15 10 18 10 21 energy (eV) 10 -27 10 -21 10 -15 10 -9 10 -3 10 3 Flux (GeV -1 m -2 s -1 sr -1 ) LHC

5. Alexander Kappes, Forschungsseminar, Humboldt-Universität, 11.02.2011c 5 The High-Energy Universe gamma-ray bursts (GRB 080319B, X-ray, SWIFT) active galactic nuclei (artist’s view) supernova remnants (SN1006, optical, radio, X-ray) micro-quasars (artist’s view)

6. Alexander Kappes, Forschungsseminar, Humboldt-Universität, 11.02.2011c 6 Accelerator (source) Shock fronts (Fermi acceleration) Objects with strong magnetic fields (pulsars, magnetars) Beam dump (secondary particle production) Interaction with photon and matter near the source Protons: pion decay Electrons: inverse Compton-scattering of photons e + γ → e + γ (TeV) High-Energy Particle Production in the Universe p + p(γ) → π ± + X μ + ν μ e + ν μ + ν e p + p(γ) → π 0 + X γ + γ (TeV)

7. Alexander Kappes, Forschungsseminar, Humboldt-Universität, 11.02.2011c 7 Why Neutrino Astronomy? Neutrinos are produced in cosmological objects Neutrinos point back to the source Neutrinos travel cosmological distances Neutrinos escape from optically thick sources Neutrinos are a clear sign for hadron acceleration Neutrinos provide complementary information to gamma-rays and protons

8. Alexander Kappes, Forschungsseminar, Humboldt-Universität, 11.02.2011c 8 Principle of Neutrino Detection muon νμνμ nuclear reaction cascade 43°   Time & position of hits μ (~ ν) trajectory Energy PMT amplitudes

9. Alexander Kappes, Forschungsseminar, Humboldt-Universität, 11.02.2011c 9 Flux from above dominated by atmospheric muons Neutrino telescopes mainly sensitive to neutrinos from below Background: Atmospheric Muons and Neutrinos atmosphere cosmic rays μ νμνμ νμνμ signal background p p μ νμνμ

10. Alexander Kappes, Forschungsseminar, Humboldt-Universität, 11.02.2011c 10 Neutrino Telescope Projects IceCube BaikalBaikal ANTARESANTARES NESTORNESTOR NEMONEMO

11. Alexander Kappes, Forschungsseminar, Humboldt-Universität, 11.02.2011c 11 Sky Coverage Visibility ANTARES (Mediterranean) > 75% 25% – 75% < 25% TeV γ-ray sources Galactic extra-Galactic Visibility IceCube (South Pole) 100% 0%

12. Alexander Kappes, Forschungsseminar, Humboldt-Universität, 11.02.2011c 12 The ANTARES Neutrino Telescope

13. Alexander Kappes, Forschungsseminar, Humboldt-Universität, 11.02.2011c 13 ANTARES in the Mediterranean Submarine cable (45km) Shore Station

14. Alexander Kappes, Forschungsseminar, Humboldt-Universität, 11.02.2011c 14 The ANTARES Neutrino Telescope -1995 m -2475 m 12 lines (885 PMTs) +1 instrumentation line Instrumented volume: ~0.01 km 3 2 m

15. Alexander Kappes, Forschungsseminar, Humboldt-Universität, 11.02.2011c 15 ANTARES Storey Hydrophone: acoustic positioning Optical Module: 10” Hamamatsu PMT in 17” glass sphere photon detection Local Control Module (in Ti cylinder): Front-end Clock, tilt/compass, power distribution… Titanium frame: support structure Optical Beacon with blue LEDs: timing calibration

16. Alexander Kappes, Forschungsseminar, Humboldt-Universität, 11.02.2011c 16 Construction Milestones 2001Installation of 40 km electro-optical cable 2002Deployment and connection of junction box 2003–2005Installation of prototype lines 2006–2008Installation of 12 lines Detector completed since May 2008 Line deployment

17. Alexander Kappes, Forschungsseminar, Humboldt-Universität, 11.02.2011c 17 Line Connection

18. Alexander Kappes, Forschungsseminar, Humboldt-Universität, 11.02.2011c Light scattering + chromatic dispersion:~ 2 ns TTS in PMTs:~ 1.2 ns → Intrinsic angular resolution 0.2˚– 0.3˚ Requires electronics + calibration: < 0.5 ns Timing Calibration Signal time in OMs relative to reference PMT

19. Alexander Kappes, Forschungsseminar, Humboldt-Universität, 11.02.2011c Acoustic positioning system Tiltmeter and compass on each storey Accuracy = 10 cm (0.5 ns) Position Calibration 20 day period March 2007 04-4-8-12 X [m] -4 0 4 -8 Y [m] Horizontal storey movement

20. Alexander Kappes, Forschungsseminar, Humboldt-Universität, 11.02.2011c 20 Optical Background 20052006 20072008 cable fault 2009 (Different colors correspond to different storeys) Single PMT rate [kHz] Optical background due to 40 K decay and bioluminescence Typical rates 60-100 kHz per photomultiplier Occasional bursts and periods of high rates Filtered by causality conditions between hits

21. Alexander Kappes, Forschungsseminar, Humboldt-Universität, 11.02.2011c 21 Up-going Neutrino Candidate

22. Alexander Kappes, Forschungsseminar, Humboldt-Universität, 11.02.2011c 22 Selected Results from ANTARES

23. Alexander Kappes, Forschungsseminar, Humboldt-Universität, 11.02.2011c 23 Atmospheric Muons & Neutrinos Up-going: ν-induced muons (~1000) ANTARES (341 days) Down-going: atm. muons

24. Alexander Kappes, Forschungsseminar, Humboldt-Universität, 11.02.2011c 24 Muon Intensity vs. Depth (90 days, 5 Lines): 2.5km 6km Astropart. Phys. 34 (2010) pp. 179-184

25. Alexander Kappes, Forschungsseminar, Humboldt-Universität, 11.02.2011c 25 Upper Limit on Diffuse Flux (334 days) IceCube 40 Strings Physics Letters B 696 (2011) 16–22

26. Alexander Kappes, Forschungsseminar, Humboldt-Universität, 11.02.2011c 26 Full-Sky Search for Point Sources (295 days) Most significant cluster Cluster of 8 events: Unbinned likelihood fit: N sig = 5.16 p-value = 0.024 (2.0 σ) Also no significant excess for selected sources Equatorial coordinates

27. Alexander Kappes, Forschungsseminar, Humboldt-Universität, 11.02.2011c 27 Flux Limits and Sensitivity 25 preliminary publication in preparation Best limits on neutrino fluxes from southern-sky sources

28. Alexander Kappes, Forschungsseminar, Humboldt-Universität, 11.02.2011c 28 Neutralino ( χ ) good WIMP candidate ANTARES data: No excess Long term investigation necessary Dark Matter Searches (WIMPs) χ ν - ν hard (W + W – ) soft (bb) ANTARES (5-line data, ~70 days) preliminary Neutralino mass [GeV] 0100200300400500600700 Φ(ν μ +ν μ ) (>10 GeV) from Sun [km -2 yr -1 ] 10 9 10 10 11 10 12 10 13

29. Alexander Kappes, Forschungsseminar, Humboldt-Universität, 11.02.2011c 29 More Physics Point sources: Gamma-ray bursts Flaring sources (e.g. AGNs) Use coincidences in neutrino telescopes to trigger optical follow-up Other topics: Neutrino oscillations (atmospheric neutrinos 10 - 100 GeV) Exotic physics (Lorentz violation, monopoles,...) Cosmogenic neutrinos (E ≳ 10 17 eV) Cosmic-ray anisotropy

30. Alexander Kappes, Forschungsseminar, Humboldt-Universität, 11.02.2011c 30 The Future Mediterranean Neutrino Telescope KM3NeT

31. Alexander Kappes, Forschungsseminar, Humboldt-Universität, 11.02.2011c 31 Current Upper Limits on Point Sources 90% C.L. upper flux limits for E -2 spectra (preliminary) ⇒ km 3 -class detector in Northern Hemisphere needed Galactic sources with TeV γ-ray emission

32. Alexander Kappes, Forschungsseminar, Humboldt-Universität, 11.02.2011c 32 KM3NeT Artist’s view Future cubic-kilometer-class Mediterranean neutrino telescope (joint effort of ANTARES, NEMO, NESTOR) Supported by ESFRI, ASPERA, ASTRONET Objectives: -Exceed Northern-hemisphere telescopes by factor ~50 in sensitivity -Exceed IceCube sensitivity by substantial factor -Provide node for earth and marine sciences -Budget: ~220 MEuro EU-funded Design Study (2006–09) and Preparatory Phase (2007–11)

33. Alexander Kappes, Forschungsseminar, Humboldt-Universität, 11.02.2011c 33 Objective: Support 3D-array of photodetectors and connect them to shore (data, power, slow control) Optical Modules Front-end electronics Readout, data acquisition, data transport Mechanical structures, backbone cable General deployment strategy Sea-bed network: cables, junction boxes Calibration devices Shore infrastructure Assembly, transport, logistics Risk analysis and quality control Technical Design Design rationale:  cost-effective  reliable  producible  easy to deploy

34. Alexander Kappes, Forschungsseminar, Humboldt-Universität, 11.02.2011c 34 OM with Many Small PMTs 31× 3” PMTs in 17-inch glass sphere (total ~140 mW) Front-end electronics (B,C) Al cooling shield and stem (A) Advantages: -autonomous detection unit with single penetrator -same photocathode area as 3 large PMTs -directional information -reduced afterpulsing -improved 1-vs-2 photo-electron separation ⇒ better sensitivity to coincidences A B C C PMT

35. Alexander Kappes, Forschungsseminar, Humboldt-Universität, 11.02.2011c 35 20 storeys Each storey supports 2 multi-PMTs Power and data cables separated from ropes; single backbone cable with breakouts to storeys Distance between DU base and first storey = 100m Flexible Towers with Horizontal Bars 2 km Footprint “building block” (optimization ongoing) 2 “building blocks” required to achieve objectives

36. Alexander Kappes, Forschungsseminar, Humboldt-Universität, 11.02.2011c 36 Point Source Sensitivities (1 year) ANTARES: 1 yr (pred. sensitivity) Predicted fluxes Halzen, AK, O’Murchadha, PRD (2008) AK, Hinton, Stegmann, Aharonian, ApJ (2006) Kistler, Beacom, PRD (2006) Costantini & Vissani, App (2005)... KM3NeT: 1 yr (pred. sensitivity) KM3NeT IceCube 80: 1 yr (pred. sensitivity) ANTARES IceCube 90% CL sensitivity for E -2 spectra (preliminary) Vision of a worldwide neutrino observatory (IceCube + KM3NeT) Large overlap region (enhanced sensitivity + cross check) SNR RX J1713 @ 5σ in 8 years

37. Alexander Kappes, Forschungsseminar, Humboldt-Universität, 11.02.2011c 37 Next steps: Prototyping and design decisions TDR public since June 2010 final decisions require site selection expected to be achieved by end of 2011 Timeline: Next Steps and Timeline now Feb 2006 Mar 2008 Jun 2010 Mar 2012 TDR CDR Design Study Preparatory phase Prototyping and construction Data taking 2014 2018 Design and site decision

38. Alexander Kappes, Forschungsseminar, Humboldt-Universität, 11.02.2011c 38 Summary Neutrino provide complementary information to gamma-rays and protons of the high-energy universe ANTARES completed since May 2008 -First results published and further analyses in full swing -No deviations from background observed -Detector likely too small to detect cosmic neutrinos KM3NeT: km 3 -class neutrino telescope in Northern Hemisphere needed to complement IceCube -In prototyping phase -Substantially improved sensitivity compared to IceCube -First data could be available in 2014