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Development of Telescopes for Extremely Energetic Neutrinos

Explore the development of telescopes for extremely energetic neutrinos, discussing 10 years of progress with optical Cherenkov detectors and new technologies. Learn about diffuse flux limits, point flux constraints, and the advancement in radio telescopes like ANITA and ARIANNA. Delve into constraints on Extremely Energetic Neutrinos (EG) point flux, utilizing various suppositions and sensitivities from different telescope projects. Discover recent developments in detecting EHE neutrinos through new technologies and predictions for cosmogenic neutrinos. Understand the importance of big detectors in capturing GZK neutrinos and the significance of recent observations in the field. Unravel the complexities of neutrino flux calculations and the ongoing quest for understanding high-energy neutrino sources.

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Development of Telescopes for Extremely Energetic Neutrinos

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  1. Development of Telescopes for Extremely Energetic Neutrinos ~300m Steven W. Barwick, UC-Irvine

  2. Neutrino Telescopes: Agenda • 10 years of progress with optical Cherenkov Detectors • Diffuse flux limits and EG point flux constraints • Extremely Energetic Neutrinos - New Technologies • Radio: ANITA and ARIANNA Teraton -Petaton

  3. 10 Years of Diffuse  Progress 100x improvement A. Silvestri, PhD Dissertation, 2008 E2 dN/dE (GeVcm-2s-1sr-1) WB Log10(E[GeV])

  4. iffuse-Fluxes << CR-Fluxes Silvestri Dissertation, 08

  5. Diffuse Flux: Limits and Models ANITA-lite HiRes RICE Auger ANITA08 AMANDA-TWR GZK Silvestri Dissertation, 2008

  6. GZK Model-Specific limits Log10(E[GeV]) all) E dN/dE (cm-2s-1sr-1) ANITA-08

  7. Excluding AGN Model Predictions for Diffuse Flux Excluded Normalization to x-ray or 1-1000 MeV ’s overproduces neutrino flux

  8. A. Silvestri 2008 10 Years of Point  Progress AM-UHE MACRO (low E) AM (5 yr) EG sources only Declination

  9. Connecting Diffuse -Flux to EG Point Sources[based on Lipari, Nucl. Instrum. Meth. A 567, 405 (2006)] Observable & Local Universe Universe observable to Diffuse Search (c/H0) c/H0 rmax   Local Universe observable to Point Search (rmax ~ 200 Mpc)  

  10. Constraining EG Point Flux • Based on sensible collection of suppositions: • EG point sources exist to redshift z=1 • L constant, or power law luminosity distribution function • Source emission described by power law energy spectrum, but details of spectrum not critical • Number of resolvable sources, Ns, obtained once point source sensitivity is specified. • In our case: • Kdiff, dN/dE = Kdiff E-2 diffuse flux • Cpoint , dN/dE = CpointE-2 point source sensitivity First derived by P. Lipari

  11. EG Point Flux Constraint AMANDA (5yr) L=1045 Silvestri PhD 08; Barwick, NIMA 09 IceCube (1 yr) L=1040 Suggests EG sources may be difficult to detect -> raises profile of Galactic sources

  12. EG Constraint Caveats • Only applies to Extragalactic (EG) sources • Not competitive for GRBs • Does not apply to “unique” source • Local nonuniformity in matter distribution does not substantially alter conclusions (Barwick, NIMA, 2009) • “Nearby” (<25 Mpc) sources possess rather small photon luminosities • Matter distribution at “Intermediate” distances within factor 2 of universal average

  13. 2005-2006: 8 strings IceCube 2007-2008 : 18 strings IceTop 2006-2007: 13 strings Air shower detector 80 pairs of ice Cherenkov tanks Threshold ~ 300 TeV In Ice 2004-2005 : 1 string 1450m AMANDA-II 19 strings 677 modules Goal of 80 strings of 60 optical modules each 17 m between modules 125 m string separation When completed, may detect <1 cosmogenic  per year 2450m Current configuration: 40 strings, 40 IceTop stations plus AMANDA 2008/09: added 19 strings Completion by 2011.

  14. Quest for EHE neutrinos New Technologies

  15. Cosmogenic (or GZK) Neutrinos Predictions are secure: p + cmb  ->  -> n + + n -> lower energy protons  ->  • However, -Flux Calculations depend on: • Elemental composition (p, Fe, mixed) • Cosmology (=0.7) • Injection Spectra, E- and Emax • Evolution of sources with redshift, (1+z)m • Star formation, QSO, GRB, little or no

  16. GZK neutrino predictions • Two significant developments • Auger confirms HiRes obs. of flux suppression, both 5 • Auger reports angular correlation between CR and nearby matter (AGN?) - not observed by HiRes (APS08) • Strengthens idea that “Ordinary” AGN responsible for UHECR • Relatively well known evolution of source • Majority of CR must be protons, else Bgal would scramble directions by more than observed • If Ang. Correlation confirmed, much (but not all!) of the GZK flux uncertainty disappears.

  17. Why Big Detectors? • GZK  Flux (E~1018 eV): 10 /km2/yr •  Interaction Length: 500 km • Event Rate/km3/yr = [10/500] ~ 0.02 • See about half the sky, 0.01/km3/yr • Efficiency, livetime, nice if more than one So GZK  detection requires > 100 km3 (aperture > 600 km3sr)

  18. ANITA-1 balloon • ANITA: • Looking for “GZK neutrinos”. • View 1 Million km3 of ice. • 32 day flight in Dec. 2006. payload radio waves 120,000 ft. Antarctic Ice Sheet 1018eV neutrino

  19. Missouri

  20. Lets get to know ANITA GPS Antennas Solar cells for NASA equipment 32 Quad-ridge horn antennas in 3 layers - 200 MHz to 1200 MHz - 10 degree down angle Battery box (Art by residents of McMurdo) 8 low gain antennas to monitor payload-generated noise ANITA electronics box (mirrored to minimize solar heating) Power for science mission

  21. SLAC beam tests on Ice Target Gorham, Barwick, et al., astro-ph/0611008 Absolute RF power and frequency dependence confirmed Width of cherenkov cone and frequency dependence confirmed

  22. Upper antenna (facing source) Lower antenna (facing source) Calibration Signals Volts (mV) Goldstein, ICRC 2007 Time (ns) Volts (mV) • Confirmed 1/r and Fresnel effects • Established absolute amplitude Time (ns)

  23. 5000 Cross-correlation (arb. linear units) Angle from zenith (degrees) 0 -1000 Relative bearing (degrees) Pointing At Calibration Events • Anthropogenic background  Need good pointing! • Pointing resolution (Δθ, Δφ) ≈ ( 0.25°, 0.75°) J. Nam Plot by J. Nam Reconstructed locations of calibration signal events

  24. Modeling Surface Roughness www.physics.ucla.edu/~moonemp/roughness Fresnel geo. facet =1.5m =5m Dookayka, APS08

  25. Well Reconstruction Event Distribution All events associated with known bases, camps, traverses or dominated by wrong (horizontal) polarization No neutrino candidates!

  26. EHE  limits Blue= proton only models Green= mixed comp. ANITA-2008 [arXiv:0812.2715v1] ANITA-2 sensitivity improves by ~2-3 Am-II Fluxes are for sum of all  flavors

  27. EHE Neutrinos Explore Higher Dimensions ~100sm For GZK E ANITA-GZK CC: sm (Anchordoqui, et al, hep-ph/0307228)

  28. ANITA Can Constrain N !(F. Wu, ICRC 07, APS08) Rate of events from ice shelf to ice sheet is related to neutrino 

  29. New Techniques to Observe Cosmogenic Neutrinos

  30. 100 x 100 array [30 km x 30 km] ARIANNA 600 m UCI, LBL, OSU, WashU, UCLA, UCLondon Barwick, astro-ph/0610631

  31. Camping at Moore’s Bay Site David Saltzberg

  32. Preliminary Value assumed prior to this work ARIANNA Site Studies Barwick, ICRC 07 Arbitrary amplitude scaling Amazing fidelity of reflected pulse from sea-water bottom -behaves as nearly flawless mirror 1-way attenuation length, averaged over depth and temperature And Radio Quiet!

  33. ARIANNA Sensitivity Greatly increases sensitivity to GZK  in E=1018-1019 eV ARIANNA + ESS Flux: 40 events/yr ARIANNA Energy Res: dE/E~1, Angular Res: ~1 deg

  34. Neutrino Cross-Section A. Connolly, 2006 ARIANNA - 10 years [] = 0.24 If Nev = 400 If  =0.5o If =2GQRS GQRS 2 parameter fit: Normalization cross-section

  35. Outlook • Requisite tools to inaugurate multi-messenger astronomy are available -> IceCube, Mediterranean efforts continue to improve this technique. • Flux from EG sources may be low -> galactic sources very important • To probe the neutrinofluxes and physics at highest energies, new techniques are being developed based on radio cherenkov , air shower and acoustic detection. • ANITA extends search volume to 106 km3 • Launched from McMurdo Dec 15, 2006, and remained aloft 35 day • Results recently released • ARIANNA spans the impending energy gap • Ice studies in Nov’ 06 astonishingly good, but not the only contender (SALSA, AURA/IceRay, Auger, acoustic detection)

  36. UHE analysis sensitive over the southern sky  ~ E-2 • Aeff as a function of declination and neutrino energy E NN2 > 0.78 NN2 > 0.78 Cen A

  37. BG & SIG Event Signature   BG Event Muon Bundle large tot SIG Event Single Muon small tot

  38. Air Shower vs Ice Shower(time profiles quite different!) 100MHz-1 GHz

  39. “GZK” suppression exists! Both HiRes and AUGER see suppression @ E ~1019.5 eV Watson, ICRC 2007

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