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Status and Results

A M A N DA Antarctic Muon And Neutrino Detector Array. Status and Results. Peter Steffen DESY Zeuthen, Germany TAUP 2003. Draft.  150 members. The AMANDA Collaboration. Bartol Research Institute UC Berkeley UC Iivine Pennsylvania State UW Madison UW River Falls LBL Berkeley

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Status and Results

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  1. A M A N DA Antarctic Muon And Neutrino Detector Array Status and Results Peter Steffen DESY Zeuthen, Germany TAUP 2003 Draft

  2.  150 members The AMANDA Collaboration Bartol Research Institute UC Berkeley UC Iivine Pennsylvania State UW Madison UW River Falls LBL Berkeley U. Simón Bolivar, Caracas VUB, Brussel ULB-IHEE, Bruxelles U. de Mons-Hainaut Imperial College, London DESY, Zeuthen Mainz Universität Wuppertal Universität Stockholm Universitet Uppsala Universitet Kalmar Universitet South Pole Station Antarctica New Zealand Venezuela (1) USA (7+3) Europe (10+1) Japan + associated IceCube institutes in USA, Europe, Japan, New Zealand

  3. Contents - Introduction - cosmic muons - atmospgeric neutrinios - search for extraterrestial neutrinos: -> diffuse flux of high energy -> diffuse flux in the PeV to 100 PeV range -> search for point sources - search for neutrinos from WIMP annihilation - other results: search for magnetic monopoles, SN monitoring cosmic ray composition - Outlook - search for GRB related neutrino burst (Kyler Kuehn) - extension of AMANDA to ICE-CUBE (Shigeru Yoshida)

  4. Physics motivation • neutrino astronomy •  origin and acceleration of cosmic rays •  understand cosmic violent processes • (AGN, SNR, GRB, MQ, ....) • dark matter (neutralino annihilation) • - neutrino properties ( , cross sections ..) • search for magnetic monopoles • search for mini black holes

  5. Supernova remnant Microquasar (SS433 etc.) Active Galaxy (optically dense, e.g. FRII)  1 LJ  106 LJ Crab nebula Black hole with  mass of sun Black hole with 108 x mass of sun extra-galactic galactic Neutrino source candidates

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

  7. Above O(PeV): significant  absorption: O(10 PeV) O(TeV): use upward going muons O(PeV): use horizontal events O(10 PeV): use events from above Detection of muon neutrinos  (e) Cosmic rays  (e) atmospheric muons earth acts as shield

  8. The Site South Pole AMANDA Amundsen-Scott Station

  9. optical module 1996-2000 AMANDA-II and SPASE South Pole Air Shower Experiment inner 10 strings: Amanda-B10 19 strings 677 PMTs AMANDA II

  10. 200 TeV e candidate Two events: muon and cascade

  11.  effective area (schematic): -interaction in earth, cuts 2 -5m2 En 2 3 cm2 100 GeV 100 TeV 100 PeV Detector capabilities •  muons: • directional error: 2.0 - 2.5° • energy resolution:¶0.3 – 0.4 • coverage: 2 •  primary cosmic rays:(+ SPASE) • energy resolution:¶0.07 – 0.10 •  „cascades“: (e±,  , neutral current) • zenith error: 30 - 40° • energy resolution:¶ 0.1 – 0.2 • coverage: 4 ¶[log10(E/TeV)]

  12. Atmospheric muons in AMANDA-II Atmospheric muons and neutrinos: AMANDA‘s test beams much improved simulation ...but data 30% higher than MC ...  normalize to most vertical bin Systematic errors: 10% scattering ( 20m @ 400nm) absorption (110m @ 400nm) 20% optical module sensitivity 10% refreezing of ice in hole PRELIMINARY threshold energy ~ 40 GeV (zenith averaged)

  13. for QGSJET generator: (H) = 2.70 ± 0.02 0 (H) = 0.106(7) m-2s-1sr-1TeV-1 Compatible and competitive () with direct measurements Cosmic Ray flux measurement In some cases ice and OM-sensitivity effect can be circumvented ... (E)=0E- empirical separation of ice and OM sensitivity effects PRELIMINARY

  14.  spectrum up to 100 TeV  compatible with Frejus data presently no sensitivity toLSND/Nunokawa prediction of dip structures between 0.4-3 TeV In future, spectrum will be used to study excess due to cosmic ‘s Atmospheric n's in AMANDA-II  neural network energy reconstruction regularized unfolding PRELIMINARY measured atmospheric neutrino spectrum 1 sigma energy error

  15. Search for extraterrestrial neutrinos - background: neutrinos from cosmic air showers strong falling energy spectrum, diffuse in direction - signal: excess of diffuse flux at high energy, accumulation at point sources • search for muon neutrinos with high energy: • upward and • downward (with extreme high energy) • - search for cascades with high energy • - search for point sources

  16. Search for diffuse excess of extraterrestrial high energy neutrinos

  17. Search for a TeV-PeV excess in the diffuse flux(upward going muons) 1997 B10-data, accepted by PRL „AGN“ with 10-5 E-2 GeV-1 cm-2 s-1 sr-1 • - hit channels as • muon energy indicator • - cuts determined by MC • blind analysis • (as all our analyses !) atm. Exp. cut E2(E) < 8 10-7 GeV-1 cm-2 s-1 sr-1

  18. Search for a PeV-100PeV excess in the diffuse flux(downward muons and muons close to horizon) EHE events very bright; many PMTs detect multiple photons vertical R 10 km Neural Net Parameter „NN2“ for neutrino vs.atm muon separation E2(E) < 7.210-7 GeV-1 cm-2 s-1 sr-1 bright MC event near horizon

  19. Synthesis 1: Diffuse limit for muon neutrinos Limits for generic E-2 spectra and specific model shapes: 3·103 – 106 GeV: E2(E) < 8 10-7 GeV-1 cm-2 s-1 sr-1 2.5·106 – 5.6·108 GeV: E2(E) < 7.210-7 GeV-1 cm-2 s-1 sr-1 prel. Expected sensitivity 2000 data: ~ 310-7 GeV-1 cm-2 s-1 sr-1

  20. Diffuse limit from cascades effective volume 80 TeV – 7 PeV PRELIMINARY for E2(E) =10-6GeV cm-2s-1sr-1 expect 9.3 e , 3.8  , 6.2  events 2 candidate events total observed 90% CL limit for e::=1:1:1 E2all (E) < 9·10 – 7GeV cm-2s-1sr-1

  21. Synthesis 2: flux limits for all flavours assuming e::=1:1:1 • multiplicative factor 3 applied for single  channel • special analysis for resonant production (6.3 PeV) 90% differential limit 2.310-20 GeV-1 cm-2 s-1 sr-1 2000  analysis will yield all-flavour limit comparable to cascade limit

  22. Search for extraterrestrial point sources

  23. Point source search in AMANDA II Search for excess events in sky bins for up-going tracks - 697 events observed above horizon - 3% non-neutrino background for  > 5° - cuts optimized in each declination band PRELIMINARY below horizon: mostly atmospheric ‘s above horizon:mostly fake events 1. Grid Search (sky subdivided into 300 bins ~7°x7° ) 2. Search around defined sources 3. Cluster Search no clustering observed - no evidence for point sources

  24. upper limits @ 90% CL in units of 10-8cm-2s-1 ¶published Ap. J, 582 (2003) Selected point source flux limits sensitivity  flat above horizon - 4 times better than B10 ¶! PRELIMINARY declination averaged sensitivity: lim  0.23•10-7 cm-2s-1 @90%

  25. N Crab Mark. 501 preliminary 2000 data GX 339-4 Antares (2007+) SS-433 AMANDA + (2007) -45 0 45 90 -90 1 km3 1 km3 detector, 3 years Expected source sensitivity muons/cm2 s1 AMANDA 137 days 10-14 S MACRO 8 years published data 10-15 10-16 10-17 declination (degrees)

  26. SS-433 -45 0 45 90 -90 Mk-501 / ~ 1 sensitivity for AMANDA 97-02 m cm-2 s-1 southern sky northern sky 4 years Super-Kamiokande 10-14 170 days AMANDA-B10 8 years MACRO 10-15 declination (degrees)

  27. Is there a signal at higher energies? no indication of clustering also at higher energies ! increasing energy deposition

  28. Search for WIMPs

  29. Indirect WIMP search  1. Neutrinos from the Center of Earth  +   b + b „soft spectrum“   W + + W - „hard spectrum“

  30. Rejection of Background We start with At this stage the data consist only of up going atmospheric neutrinos and a possible WIMP signal events at trigger level in99 data

  31. Effective volume = # events that pass the cuts = # events generated in a volume around the detector

  32. Looking to the center of the earth Number of events No statistically significant excess of vertical muons on top of the expected atmospheric neutrino background NO WIMP SIGNAL HAS BEEN DETECTED ! cosine (muon zenith angle)

  33. upper limits on the muon flux from neutralino annihilations in the center of the earth • Improvement of upper limits from 99-data analysis compared to • 97-data analysis • is due to • the larger 1999 effective live time •  the development • of cuts adapted • to each WIMP • mass individually

  34. Indirect WIMP search 2. Neutrinos from the Sun    Amanda At South Pole the Sun sinks maximally 23° below horizon. Therefore only Amanda-II with ist considerably improved reconstruction for horizontial tracks (compared to Amanda-B10) can be used for solar WIMP search.

  35. Upper limits (sensitivities) on the muon flux coming from neutralino annihilations in the center of the Sun AMANDA-II results: • based on 193 days of live time • Exclusion sensitivity from analyzing the off-source bins Will un-blind data soon and look to the Sun. preliminary ANTARES and ICECUBE: MC-calculated sensitivities

  36. - Search for monopoles - Supernova monitoring - Cosmic ray composition

  37. Relativistic Magnetic Monopoles 10-14 Soudan KGF Baikal 10-15 MACRO Cherenkov-Light  n2·(g/e)2 Orito upper limit (cm-2 s-1 sr-1) 10-16 Amanda n = 1.33 (g/e) = 137/ 2  electrons 10-17 IceCube 10-18  8300 0.50 0.75 1.00  = v/c

  38. Count rates 0 5 10 sec Supernova Monitor Amanda-II B10: 60% of Galaxy A-II: 95% of Galaxy IceCube: up to LMC Amanda-B10 IceCube

  39. iron AMANDA (correlate to #muons) proton log(E/GeV) SPASE-2 (correlated to #electrons) robust evidence for composition change around knee ... cosmic ray composition studies SPASE-2 (electronic component) - AMANDA B10 (muonic component) - unique combination! AMANDA II

  40. blue band: detector and model uncertainties red band: uncertainty due to low energy normalization confirms trend seen by other experiments ... Composition change around „knee“ 1015 eV 1016 eV A=30 A=6 publication in preparation 1998 data

  41. Chem. Composition Iron 1 km Proton AMANDA (number of muons) log(E/PeV) 2 km Spase (number of electrons) Chemical Composition preliminary

  42. Outlook (still to be done)

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