1. Neutrino Astronomy introductionintroduction the cosmic ray puzzle revisitedthe cosmic ray puzzle revisited theory of high energy neutrino detectiontheory of high energy neutrino detection

2. Neutrino Sources generic neutrino flux associated with the sources of the cosmic rays: 1.point 2. diffuse sourcegeneric neutrino flux associated with the sources of the cosmic rays: 1.point 2. diffuse source one example: gamma ray burstsone example: gamma ray bursts other science, one example: the search for dark matterother science, one example: the search for dark matter

3. Neutrino Telescopes First generation: AMANDAFirst generation: AMANDA Kilometer-scale neutrino observatory:Kilometer-scale neutrino observatory:IceCube

4. Energy (eV ) Radio CMB Visible GeV  -rays 1 TeV = 1 Fermilab Flux 400 microwave photons per cm 3

5.  +  CMB  e + + e - With 10 3 TeV energy, photons do not reach us from the edge of our galaxy because of their small mean free path in the microwave background.

6. TeV sources! cosmic rays //////////////////////////////////

7. Proton Astronomy?  = ~=~= d ____ R gyro dB ___ E d ______ 1 Mpc B ______ 10 -9 G E _________ 3 x 10 20 eV  ___ 0.1 o ~=~= [ []] B ~ 10 -6 Gauss in local cluster?

8. Interaction length of protons in microwave background p +  CMB  + n   p = ( n CMB   ) -1  10 Mpc  10 Mpc p +  CMB GZK cutoff above ~ 50 EeV

9. 1 pc ~ 3 ly ~ 10 18 cm 1000 Mpc 100 Mpc 10 Mpc 1 Mpc 100 kpc 10 kpc 1 kpc 0.1 kpc gamma ray bursts closest active galaxies local supecluster Virgo halo center of galaxy galaxy (scale height)

10. Multi-Messenger Astronomy Protons,  -rays, neutrinos, [gravitational waves] as probes of the high-energy Universe probes of the high-energy Universe 1. Protons: directions scrambled by magnetic fields 1. Protons: directions scrambled by magnetic fields n 2.  -rays : straight-line propagation but 2.  -rays : straight-line propagation but reprocessed in the sources reprocessed in the sources extragalactic backgrounds absorb E  > TeV 3. Neutrinos: straight-line propagation, unabsorbed, but difficult to detect unabsorbed, but difficult to detect

11. New Window on Universe? Expect Surprises New Window on Universe? Expect Surprises

12. Knee of spectrum Differential spectral index changes at ~ 3 x 10 15 eVDifferential spectral index changes at ~ 3 x 10 15 eV – a = 2.7  a = 3.0 –Continues to 3 x 10 18 eV –Expect exp{-E / Z E max } cutoff for each Z Fine-tuning problem:Fine-tuning problem: – to match smoothly a new source with a steeper spectrum (Axford) –How serious is this? Knee

13. Transition to extragalactic origin? AnkleAnkle new population of particles? new population of particles? Suggestive evidence:Suggestive evidence: – hardening of spectrum – change of composition Measurements:Measurements: –Energy –Depth of maximum (X max ) –N m / N e Ankle New component with hard spectrum?

14. Generic Spectrum with Cosmological Evolution sources evolve ~(1+z) 3

15. Energy Spectrum by AGASA (θ< 45) 10 obs. / 1.6 exp. 4.0σ

16. Models of Cosmic Rays Bottom up –GRB fireballs –Jets in active galaxies –Accretion shocks in galaxy clusters –Galaxy mergers –Young supernova remnants –Pulsars, Magnetars –Mini-quasars –… Observed showers either protons (or nuclei)Top-down –Radiation from topological defects –Decays of massive relic particles in Galactic halo –Resonant neutrino interactions on relic ’s (Z- bursts) Mostly pions (neutrinos, photons, not protons) Disfavored! Highest energy cosmic rays Highest energy cosmic rays are not gamma rays are not gamma rays Overproduce TeV-neutrinos Overproduce TeV-neutrinos

17. 10 24 eV = 10 15 GeV ~ M GUT topological defects topological defects (vibrating string, annihilating monopoles) (vibrating string, annihilating monopoles) heavy relics ? heavy relics ? Top. Def.  X,Y  W,Z  quark + leptons photons >> protons top-down spectrumtop-down spectrum neutrinos>>photons>>protonshierarchy: neutrinos>>photons>>protons are cosmic rays the decay product of _

18. Acceleration to 10 21 eV? ~10 2 Joules ~ 0.01 M GUT dense regions with exceptional gravitational force creating relativistic flows of charged particles, e.g. coalescing black holes/neutron stars dense cores of exploding stars supermassive black holes

19. CasA Supernova Remnant in X-rays John Hughes, Rutgers, NASA Shock fronts Fermi acceleration

20. Active Galaxies: Jets VLA image of Cygnus A 20 TeV gamma rays Higher energies obscured by IR light

21. Fermi acceleration Jets Black Hole Accretion Disk Shock fronts

22. Challenge I: Acceleration R B shock velocity (V = e  = v/c   = boosted energy from cosmic accelerator 

23. Superluminal motion : boosted accelerators telescope: 1 year later 3 ly light from blob is only 1 year behind that from agn! ' accelerator frame exp:  10 <~ E obs =  E'  t obs =  -1  t' 4c 1c3c 5c 

24. Cosmic Accelerators E ~  BM energy magnetic field boost factor mass E ~  cBR R ~ GM/c 2

25. E (eV) = B (Tesla) R 2 (m) 2  __ T ms-pulsarFermilab R10 km few km B10 8 Tfew T T -1 10 3 10 5 (#revs -1 ) E10 19 eV~10 12 eV= 1 TeV

26. E ~  B M quasars   1 B  10 3 G M  10 9 M sunquasars   1 B  10 3 G M  10 9 M sun blasars 10blasars 10 neutron stars   1 B  10 12 G M  M sunneutron stars   1 B  10 12 G M  M sun black holes black holes.. grb  10 2grb  10 2 E > 10 19 eV ? emit highest energy  ’s! >~ >~

27. cosmic neutrinos associated with cosmic rays

28. radiation enveloping black hole p +  -> n +  + ~ cosmic ray + neutrino -> p +  0 -> p +  0 ~ cosmic ray + gamma

29. Irrespective of the cosmic-ray sources, some fraction will produce pions (and neutrinos) as they escape from the acceleration site pions (and neutrinos) as they escape from the acceleration site through hadronic collisions with gas through hadronic collisions with gas through photoproduction with ambient photons through photoproduction with ambient photons Cosmic rays interact with interstellar light/matter even if they escape the source escape the source Transparent:Transparent: protons (EeV cosmic-rays) ~ photons (TeV point sources) ~neutrinos Obscured sourcesObscured sources Hidden sourcesHidden sources Unlike gammas, neutrinos provide unambiguous evidence for cosmic ray acceleration! Sources:

30. Requires kilometer-scale neutrino detectors neutrino detectors

31. Produces cosmic ray beam? Radiation field: Radiation field: Ask astronomers active galaxy

32. Supernova shocks expanding in interstellar medium Crab nebula

33. Galactic Beam Beam Dump Dump

34. Modeling yields the same conclusion: Line-emitting quasars such as 3C279 Beam: blazar jet with equal power in electrons and protons Target: external quasi-isotropic radiation N events ~ 10 km -2 year -1 Supernova remnants such as RX 1713.7-3946 (?) Beam: shock in interstellar medium Target: molecular cloud

35. even neutrons do not escape do not escape neutrons escape escape neutrinos associated with the source of the cosmic rays?

36. neutrino muon or tau Cerenkov light cone Detector interaction Infrequently, a cosmic neutrino is captured in the ice, i.e. the neutrino interacts with an ice nucleus The muon radiates blue light in its wake In the crash a muon (or electron, or tau) is produced Optical sensors capture (and map) the light

37. Optical Module

38. How to build a detector? Use the phenomenon of Cherenkov light

39. Copyright © 2001 Purdue University

40. neutrino muon or tau Cherenkov light cone Detector interaction Infrequently, a cosmic neutrino is captured in the ice, i.e. the neutrino interacts with an ice nucleus In the crash a muon (or electron, or tau) is produced The muon radiates blue light in its wake Optical sensors capture (and map) the light

41. South Pole AMANDA– 1 mile deep

42. Size perspective 50 m

43. the AMANDA detector Construction began in 1995 (4 strings)Construction began in 1995 (4 strings) AMANDA-II completed in 2000 (19 strings total)AMANDA-II completed in 2000 (19 strings total) 677 optical modules677 optical modules 200 m across200 m across ~500 m tall (most densely instrumented volume)~500 m tall (most densely instrumented volume)

44. AMANDA Event Signatures: Muons  + N   +X  + N   + X charged current muon neutrino interaction  track

45. Two events... 200 TeV e candidate

46. Detection of e, ,  ~ 5 m Electromagnetic and hadronic cascades O(km) long muon tracks direction determination by cherenkov light timing  15 m

47. Optical Cherenkov Neutrino Telescope Projects NESTOR Pylos, Greece ANTARES La-Seyne-sur-Mer, France BAIKAL Russia DUMAND Hawaii (cancelled 1995) AMANDA, South Pole, Antarctica NEMO Catania, Italy

48. Northern hemisphere detectors Nestor March 29, 2003 1 of 12 floors deployed 4000 m deep completion: 2006 Antares March 17, 2003 2 strings connected 2400 m deep completion: start 2006 Baikal NT200 1100 m deep data taking since 1998 new: 3 distant strings

49. ANTARES Layout 12 lines 25 storeys / line 3 PMT / storey ~60-75 m 350 m 100 m 14.5 m Junction box Readout cables 40 km to shore

50. GZK Cosmic Rays & Neutrinos Cosmogenic Neutrinos are Cosmogenic Neutrinos are Guaranteed if primaries Guaranteed if primaries Nucleons. Nucleons. May be much larger fluxes, May be much larger fluxes, for some models, such as for some models, such as topological defects topological defects p +  CMB   + ….

51. Radio Emission from neutrino- induced electromagnetic cascades Electromagnetic cascades: electron-positron pairs and (mostly) gammas  electrically neutral, no radio emission. (mostly) gammas  electrically neutral, no radio emission. Compton scattering of photons on atomic electrons creates Compton scattering of photons on atomic electrons creates negative charge excess of ~ 20% negative charge excess of ~ 20% Negative charge radiates coherently at MHz ~ GHz  Negative charge radiates coherently at MHz ~ GHz  Power = Energy 2 Askarian effect demonstrated at SLAC: consistent with Askarian effect demonstrated at SLAC: consistent withcalculations

52. Antenna & Cable Neutrino enters ice Neutrino interacts Two cones show 3 dB signal strength Cube is.6 km on side Installed ~15 antennas Installed ~15 antennas few hundred m depth with few hundred m depth with AMANDA strings. AMANDA strings. Tests and data since 1996. Tests and data since 1996. Most events due to local Most events due to local radio noise, few candidates. radio noise, few candidates. Continuing to take data, Continuing to take data, and first limits prepared. and first limits prepared. Proposal to Piggyback with Proposal to Piggyback with ICECUBE ICECUBE RICE Radio Detection in South Pole Ice

53. ANITA Radio from EeV ν’s in Polar Ice NASA proposal now NASA proposal now Data in 2005 if successful Data in 2005 if successful

54. Using Mountains to Convert ν TauWatch Using Mountains to Convert ν τ 3/02 Workshop in Taiwan, see http://hep1.phys.ntu.edu.tw/vhetnw

55. Ocean Acoustic Detection G.Gratta, atro-ph/0104033 New Stanford Effort using US Navy Array pancake beam pattern US Navy acoustic tracking range in Tongue of the Ocean, Atlantic Hydrophones 1550-1600 m deep

56. Compare Potential GZK Neutrino Detectors

57. notes to previous table

58. Event Rates volumeeff. areathreshold OWL10 13 ton10 6 km 2 3x10 19 eV OWL10 13 ton10 6 km 2 3x10 19 eV IceCube10 9 ton1km 2 10 15 eV* IceCube10 9 ton1km 2 10 15 eV* Events per year TDz burst p OWL e 1695 OWL e 1695 Ice Cube  11301.5 Ice Cube  11301.5  2.7 Cline, Stecker astroph 0003459 Alvarez-Muniz astroph 0007329 Warning: models identical? *actual threshold ~100GeV, > 1 PeV no atmospheric background

59. l The Earth as a cosmic ray muon filter P survival = exp -(l/ ) = n  (E ) n =  N A

60. Neutrino Detection Probability neutrinosurvives neutrinodetected e-e-e-e- 1 - e - ~_ L_ L_ L e   E  __ m  for  : L R  [E  = (1 - y) E ] for   : L c   L_ P det = nL  P det = nL 

61. Range of the Muon dE  ___ dR  = - (   +   E  )  (R   2 MeV cm 2 /g 6 x 10 -6 cm 2 /g (0.8 x 10 -6 for  low E  R    E  = 5m large E  R  ln ( ) 1___    E___ E  ~_ ~_ ___GeV

62. Energy reconstruction Energy reconstruction will be a powerful tool in order to discriminate between astrophysical neutrinos and those coming from atmospheric interactions. The muon energy reconstruction is based on the fact that the higher its energy, the higher the energy loss along its track. The method is only valid above the critical energy (  600 GeV), where energy losses caused by radiative processes dominate over ionisation processes.  : ionisation  : radiative processes

63. Neutrino Astronomy Explores Higher Dimensions 100 x σ SM GZK range

64. Detection of  (E ) N events = P survival P detected Area  N events = P survival P detected Area  Area = L 2 Area = L 2 for detailed geometry and kinematics: Physics Reports 258 (3), 173 (1995) hep-ph/0105067

65.  secondary lepton l (k') (1 - y) E = E' Q 2 = - (k - k') 2 M 2 W ~_ (k) (k) p y E hadronic shower q(x) d 2  d 2 _____ dxdQ 2 G 2 F G 2 F___  M 2 W M 2 W_________ Q 2 + M 2 W = [ ] 2 q( x,Q 2 ) = [ ] 2 q( x,Q 2 )

66. d 2  d 2 _____ dxdQ 2 QCD evolution Increasing Q 2 M 2 W x q(x) xxxx M2WM2WM2WM2W Q2Q2Q2Q2 x d 2  d 2 _____ dxdQ 2 G 2 F G 2 F___  M 2 W M 2 W_________ Q 2 + M 2 W = [ ] 2 q ( x,Q 2 ) = [ ] 2 q ( x,Q 2 ) 