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The Wierdest wonder

The Wierdest wonder

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The Wierdest wonder

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  1. The Wierdest wonder • Is it good or is it bad? Per Olof Hulth

  2. AMANDA experience • Bad • Calibration of the detector very heavy (“perfect” time constants for AMANDA-B13 ready first May 2000!) The analysis delayed due to this. • Good • Deployment procedure established. • “Easy” to reconstruct neutrinos Per Olof Hulth

  3. AMANDA deployment history Per Olof Hulth

  4. AMANDA data analysis • The first neutrino candidates published from AMANDA-B4 (data 1996) • AMANDA-B10 data 1997 analysis in progress for • Atmospheric neutrinos • Search for WIMP annihilation in the Earth • n point sources • Diffuse n flux • Neutrinos from GRB • and Supernova, magn. monoples, AMANDA-SPASE etc Per Olof Hulth

  5. AMANDA-II Feb. 00 Per Olof Hulth

  6. AMANDA n-candidate • Early photons are red, late photons are blue. More photons are larger circles • Bottom of array is toward center of Earth • The muon is clearly traveling in the upward direction Per Olof Hulth

  7. AMANDA n-candidate • Early photons are red, late photons are blue. More photons are larger circles • Bottom of array is toward center of Earth • The muon is clearly traveling in the upward direction Per Olof Hulth

  8. Search Strategies for HE n’s • Diffuse flux are most difficult to detect, but largest predicted rates. • GRBs have least background due to time and position correlations. Per Olof Hulth

  9. Signal-background Separation Arb. normalization between signal and BG Per Olof Hulth

  10. SPASE-AMANDA SPASE: South Pole Air Shower Experiment • Calibration of absolute pointing • Calibration of pointing resolution • Calibration of signal efficiency Per Olof Hulth

  11. Data Reduction 1997 E.g. one of the atmospheric neutrino analysis, 1997. Per Olof Hulth

  12. Atm. n: background rejection • Satisfactory agreement at all stages of analysis • Rejection criteria are progressively improved, leaving fewer down-going events • Initially data agrees with BG simulation, but then agrees with atm. n signal 103 1 Per Olof Hulth

  13. Angular Distributions Two distinct analysis techniques, but not independent (a) (b) MC (normalized) Per Olof Hulth

  14. Atmospheric Neutrinos • Stronger selection criteria than point analysis • Two distinct analysis methods • Expected number of events depends on analysis efficiency Per Olof Hulth

  15. Search for HE n Point Sources • Concentrate on continuous emission from sources with hard spectra (~E-2) • Optimize search on Signal to Noise Ratio • Aeff depends on rejection requirements • Iterative procedure defined a priori • Background for this search • Poorly reconstructed atmospheric muons • Atmospheric neutrinos Per Olof Hulth

  16. Sky Plot of Events Equatorial Coordinates • 1097 events • No obvious clustering • Event sample consists of atm. n and atm. muons. Per Olof Hulth

  17. Significance distribution • Bin sky according to angular resolution • Use declination band to estimate background • No statistically significant excess Per Olof Hulth

  18. Flux Limit (preliminary) • AMANDA B10 limits are compared to MACRO limits. SuperK curve is estimated! • AMANDA-II will complement sky coverage of SuperK Per Olof Hulth

  19. Point Source Fluxes Figure adopted from Mannheim & Learned • Theoretical predictions are very small • AMANDA limit assumes source with E-2 spectrum Per Olof Hulth

  20. Mk 501 Flux Limit • Recent diffuse IR measurements imply strong attenuation of TeV photons • AMANDA can rule out similar neutrino spectrum. Figure adapted from Protheroe and Meyer, astro-ph/0005349 AMANDA Per Olof Hulth

  21. Search for Diffuse Flux • OM multiplicity distribution is (weakly) related to energy deposition. • Distribution is consistent with atm n • New energy estimators will lead to improved limits Per Olof Hulth

  22. Diffuse Flux • Generally 103 larger than point fluxes • Atm. n backgrounds 103 worse • E2Fn < 1.6x10-6 GeVcm-2s-1sr-1 AMANDA Per Olof Hulth

  23. WIMPs from Sun/Earth Per Olof Hulth

  24. Angular Spread of WIMP signal • Angular spread decreases as WIMP mass increases, reducing atm. n background Per Olof Hulth

  25. Cuts for WIMP search • Optimized cuts for almost vertical upward moving muons. • The simulated WIMP signal is reduced to 30% after reducing background by 108. Per Olof Hulth

  26. WIMPs from the Earth Optimized search for vertical neutrinos (1997 data) • AMANDA limits comparable to MACRO and Baksan • AMANDA sensitivity will increase at low mass due to special string trigger and better optimized analyzes Per Olof Hulth

  27. WIMP search with Ice3 The WIMP search has been tested for two different geometries and the limits are given for 10 years of running Per Olof Hulth

  28. WIMPs from the Earth with Ice3 Optimized search for vertical neutrinos • Ice3 will significantly improve the sensitivity. Per Olof Hulth

  29. WIMPs from the Earth with Ice3 Optimized search for vertical neutrinos • Ice3 will completely cover the DAMA area Per Olof Hulth

  30. WIMPs from the Sun with Ice3 • Ice3 will significantly improve the sensitivity. Per Olof Hulth

  31. WIMPs from the SUN with Ice3 Per Olof Hulth

  32. Search for HE n from GRB Per Olof Hulth

  33. GRB Science • Verify fireball model • GRBs may be sources of highest energy cosmic rays • Test of special relativity • Search for nt appearance at Dm2> 10-17 eV2(Ice3) • Search for n emission in coincidence with Gamma ray detectors Per Olof Hulth

  34. HE n emission from GRB’s ? - Not so far 10-1 Combined Limit (90% CL) Fluence (TeVcm-2) 10-6 Waxman and Bahcall 1 100 Burst Duration (s) Per Olof Hulth

  35. AMANDA Supernova detection • ne + p n + e+ • PMT noise increase due to the positrons • AMANDA records noise on the PMTs over 0.5 sec and summing up total rate over 10 sec intervals Per Olof Hulth

  36. AMANDA SN sensitivity • AMANDA-B10 has a sensitivity for SN up to the centre of our galaxy • Aim to connect AMANDA SuperK, MACRO, LVD, SNO,.. in an early warning SN system Per Olof Hulth

  37. AMANDA Effective Area • AMANDA-II 30,000-50,000 m2 • AMANDA-II has nearly uniform response over all zenith angles Per Olof Hulth

  38. Summary and Outlook • No point sources (AGN, GRB or WIMPS) detected, but • more data on tape with bigger array (1998, 1999) • ~170 atmospheric neutrinos candidates • Number depends on efficiency of analysis • Sensitivity and performance confirmed (to within factor of 2) by atm n, background studies, and Spase-AMANDA coincidence events • AMANDA-II is taking data Per Olof Hulth

  39. Publications • Many conference reports • So far X Ph.D. Thesis based on AMANDA • First neutrino results in Astroparticle Physics 13 (2000) 1, (AMANDA-B4) • Six drafts in preparation for submission in autumn 2000 (AMANDA-B10, 1997 data) • Atmospheric neutrinos • WIMP search • Neutrino limits from GRB • Point sources • Diffuse limit • AMANDA-SPASE Per Olof Hulth

  40. AMANDA Results • Supermassive Black Holes (AGN) • E-2 point source: fn (>10 GeV) <10-7 (cm-2s-1) • E-2 diffuse flux : E2fn< 1.6x10-6GeV cm-2s-1sr-1 • GRB in coincidence with BATSE • Cumulative Fluencen< 4x10-4 cm-2TeV • Atmospheric neutrinos (138 live days) • ~170 events from 1997, depends on analysis • Calibration of sensitivity within factor 2 • WIMPs from the earth Also, see ICRC99 for limits on relativistic monopoles, search for SNa, ice properties Per Olof Hulth