1. UW River Falls, May 15-16, 2003 Searching for Dark Matter Through South Pole Ice Kurt Woschnagg University of California - Berkeley

2. UW River Falls, May 15-16, 2003 Outline of Talk Introduction Whats the Matter with Matter? Are WIMPs Whats Missing? WIMP Detection and Neutrinos Detecting Neutrinos with Ice(Cube & AMANDA) Summary

3. UW River Falls, May 15-16, 2003 Introduction Edwin Hubble 1929: The Universe is expanding! Whats the fate? Too much Just right Too little Big C R U N C H Vast EXP A N S E

4. UW River Falls, May 15-16, 2003 1999: Accelerating Expansion !!

5. UW River Falls, May 15-16, 2003

6. Whats the Matter with Matter? Its Missing! –Let 0 be the energy density of the Universe –Evidence Suggest 0 =1 Cosmic Microwave Radiation Background measurements beginning High Red-shift Type 1a supernovae long ago Matter observations recent

7. UW River Falls, May 15-16, 2003 Whats the Matter with Matter? Ordinary Matter is less than 0.05 0

8. UW River Falls, May 15-16, 2003 Are WIMPs Whats Missing? Relics from the past –Weakly Interacting Massive Particles Weak interactions Survival Appreciable Mass Neutralinos to the rescue –Scatter off nuclei of ordinary matter –Become gravitationally trapped in the Earth –Neutrinos produced from annihilations

9. UW River Falls, May 15-16, 2003 WIMP annihilation qq ll WW ZZ, Higgs… Earth Detector

10. UW River Falls, May 15-16, 2003 Neutrinos: The Ideal Messengers? Neutral –Not affected by magnetic fields Weakly interacting –Pass (straight) through intervening matter –Escape high-density/energy environment Abundant –Most prevalent particles

11. UW River Falls, May 15-16, 2003 Neutrinos have helped us before: In our solar system: Neutrinos from the Sun prove internal fusion Just outside our galaxy: Neutrinos from Supernova 1987A explain last gasp of dying stars Well beyond our galaxy: Neutrinos from massive Black Holes…some day Need to look at higher energies larger detectors! However…

12. UW River Falls, May 15-16, 2003 I have done a terrible thing, I have invented a particle that cannot be detected. Wolfgang Pauli Only weak interactions indirect detection

13. UW River Falls, May 15-16, 2003 How to build a neutrino detector Look for the neutrinos interaction product (e,, ) Use the earth as a filter Needle in haystack: 1 in 1,000,000 is Earth Detector cosmic ray

14. UW River Falls, May 15-16, 2003 Cherenkov radiation: sonic boom of light How to detect muons from neutrinos

15. UW River Falls, May 15-16, 2003 Need something transparent Need large volume of it Cant pay a lot for it Need electricity, food, transportation, etc Antarctic ice is the purest, most transparent natural medium on earth South Pole ice cap is two miles thick South Pole ice is free US has permanent base at South Pole Build it at the South Pole!

16. UW River Falls, May 15-16, 2003 AMANDA Antarctic Muon and Neutrino Detector Array –677 light sensors –200 m diameter, 600m high –Buried under 1400 m of ice Popular Science April, 2001, p. 70 Hunting the Invisible ~4 neutrinos per day

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18. Holes are drilled with hot water 2000 m deep 60 cm wide 3-4 days

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20. Antarctic geography South Pole Amundsen-Scott station (US) McMurdo station Lake Vostok New Zealand & US Greenwich (UK)

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25. Amundsen-Scott South Pole station South Pole Dome Skiway Summer camp IceCube AMANDA North Dark sector

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27. The Dome The new station

28. UW River Falls, May 15-16, 2003 Summer camp

29. UW River Falls, May 15-16, 2003 The AMANDA counting house: MAPO (Martin A. Pomerantz Observatory)

30. UW River Falls, May 15-16, 2003 WIMPs seen so far: 0 Just started looking Need more time to catch one, or Need bigger detector IceCube – 1 km 3 of ice

31. UW River Falls, May 15-16, 2003 IceCube 1400 m 2400 m AMANDA South Pole Skiway 80 Strings 4800 sensors 1 km 3 volume (1Gt) First string to be deployed in Dec 2004 To be completed in 2010 AMANDA contained within IceCube ~300 neutrinos per day Surface IceTop

32. UW River Falls, May 15-16, 2003 IceTop tank

33. UW River Falls, May 15-16, 2003 11 US and 10 European institutions and 1 Japanese university (most of them are also AMANDA member institutions) (most of them are also AMANDA member institutions) 1.Bartol Research Institute, University of Delaware 2.BUGH Wuppertal, Germany 3.Universite Libre de Bruxelles, Brussels, Belgium 4.CTSPS, Clark-Atlanta University, Atlanta USA 5.DESY-Zeuthen, Zeuthen, Germany 6.Institute for Advanced Study, Princeton, USA 7.Dept. of Technology, Kalmar University, Kalmar, Sweden 8.Lawrence Berkeley National Laboratory, Berkeley, USA 9.Department of Physics, Southern University and A\&M College, Baton Rouge, LA, USA 10.Dept. of Physics, UC Berkeley, USA 11.Institute of Physics, University of Mainz, Mainz, Germany 12.Dept. of Physics, University of Maryland, USA 13.University of Mons-Hainaut, Mons, Belgium 14.Dept. of Physics and Astronomy, University of Pennsylvania, Philadelphia, USA 15.Dept. of Astronomy, Dept. of Physics, SSEC, PSL, University of Wisconsin, Madison, USA 16.Physics Department, University of Wisconsin, River Falls, USA 17.Division of High Energy Physics, Uppsala University, Uppsala, Sweden 18.Fysikum, Stockholm University, Stockholm, Sweden 19.University of Alabama, Tusceloosa, USA 20.Vrije Universiteit Brussel, Brussel, Belgium 21.Chiba University, Japan 22.Imperial College London, UK The IceCube Collaboration

34. UW River Falls, May 15-16, 2003 Summary Only 5% of matter is ordinary matter WIMPs are missing-matter candidates Neutrinos can be used to detect WIMPs Neutrinos are detected indirectly AMANDA (and soon IceCube) looks for WIMPs trapped in the center of the Earth and the Sun