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Carlos de los Heros Division of High Energy Physics Uppsala University EPS2005

GETTING THERE: FROM AMANDA TO ICECUBE. Carlos de los Heros Division of High Energy Physics Uppsala University EPS2005 Lisbon, July 21-27, 2005. THE ICECUBE COLLABORATION. Sweden: Uppsala Universitet Stockholm Universitet Kalmar Universitet. USA:

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Carlos de los Heros Division of High Energy Physics Uppsala University EPS2005

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  1. GETTING THERE: FROM AMANDA TO ICECUBE Carlos de los Heros Division of High Energy Physics Uppsala University EPS2005 Lisbon, July 21-27, 2005

  2. THE ICECUBE COLLABORATION Sweden: Uppsala Universitet Stockholm Universitet Kalmar Universitet USA: Bartol Research Institute, Delaware Univ. of Alabama Pennsylvania State University UC Berkeley UC Irvine Clark-Atlanta University Univ. of Maryland IAS, Princeton University of Wisconsin-Madison University of Wisconsin-River Falls LBNL, Berkeley University of Kansas Southern University and A&M College, Baton Rouge Germany: Universität Mainz DESY-Zeuthen Universität Dortmund Universität Wuppertal Universität Berlin UK: Imperial College, London Oxford University Belgium: Université Libre de Bruxelles Vrije Universiteit Brussel Universiteit Gent Université de Mons-Hainaut Netherlands: Utrecht University Japan: Chiba university New Zealand: University of Canterbury In March 2005, AMANDA merged into the IceCube collaboration

  3. NEUTRINO ASTRONOMY • Cosmic rays @ >>TeV exist  acceleration sites must sit somewhere Candidate sources: • SNe remnants, mQuasars • Active Galactic Nuclei • Gamma Ray Bursts • Exotics (decays of topological defects...) explained by SN? proton accelerators ? unexplained • Guaranteed sources: • atmospheric neutrinos (from p& K mesons decay) • galactic plane: • CR interacting with ISM, concentrated on the disk • CMB (diffuse): • UHE p g D+ n p+ (p p0) • Neutrinos: not absorbed, not deflected:  difficult to detect • Protons: deflected in magnetic fields, GZK • g-rays: propagate straight, however: • reprocessed in sources • absorbed in IR (100 TeV) and 3K (10 PeV)

  4. “Up-going” (from Northern sky) “Down-going” (from Southern sky) THE AMANDA DETECTOR 1996 1997 2000 AMANDA-B4 (first 4-string prototype) 4 strings 80 OMs Data years: 1996 AMANDA-B10 (inner core of AMANDA-II) 10 strings 302 OMs Data years: 1997-99 AMANDA-II 19 strings 677 OMs Data years: 2000 – What’s up? Optical Module PMT noise: ~1 kHz

  5. THE SITE South Pole road to work Station facilities AMANDA 1500 m Amundsen-Scott South Pole station 2000 m [not to scale]

  6. NEUTRINO DETECTION IN POLAR ICE South Pole ice: (most?) transparent natural condensed material Event reconstruction by Cherenkov light timing O(km) long muon tracks O(10m) Cascades, nentNeutral Current ~15 m Longer absorption length → larger effective volume

  7. IN THIS TALK: • Results from: • atmospheric neutrinos • searches for an extra-terrestrial n flux: • galactic center • diffuse (anytime, anywhere) • point source (anytime, somewhere) • transient (known ‘flary’ objects & GRBs) (sometime, somewhere) • search for WIMPs: Excess from the center of the Sun/Earth • SN search in the Milky Way Agreed collaboration strategy: Analyses are done ‘blind’. Cuts optimized on a % of data or on a time-scrambled data set.

  8. AMANDA: sensitive in very different energy regimes Energy range production site(s) galactic extra galactic

  9. TEST BEAMS: ATMOSPHERIC MUONS cosmic ray muons Atmospheric muons: - AMANDA test beam: Im vs depth, CR composition - Background for other searches • SPASE (scintillator array @ 3000m) • e density @ surface • shower core resolution: 0(m) • shower direction resolution: < 1.5o • AMANDA • m‘s @ >1500m(>300 GeV @ surface) • use SPASE core position for combined fit • use expected lateral photoelectron/event • distribution as estimate of Nm • Combined SPASE-AMANDA ‘detector’: • - Probes hadronic (m) and EM (e) component of the primary shower • - s(E) ~ 0.07 in log(Eprim) • - Results compatible with composition • change around the knee • - Sources of systematic uncertainties: • (~30% in ln(A), not shown in the plot) • -shower generation models • -muon propagation EHadron E-2.7 0.02

  10. TEST BEAMS: ATMOSPHERIC NEUTRINOS Atmospheric neutrinos: - Guaranteed test beam - Background for other searches First spectrum > 1 TeV (up to 300 TeV) - matches lower energy Frejus data • ►Neural Network energy • reconstruction of up-going μ`s • ►Regularized unfolding • →nenergy spectrum horizontal vertical Frejus • Set limit on cosmic neutrino flux: • How much E-2 cosmic ν - signal • allowed within uncertainty of • highest energy bins? Amanda E2μ(E) < 2.6·10–7 GeV cm-2 s-1 sr-1 Limit on diffuse E-2νμflux (100 -300 TeV):

  11. n’s FROM THE GALACTIC PLANE • Expected from CR+galactic interstellar medium • n’s follow the primary energy spectrum, E-2.7 • Location of AMANDA  reach only outer region of the galactic plane: 33o<d<213o • data sample 2000-03: 3329 n evts • Three signal ansatz: • Line source • Gaussian source • Diffuse source (*) NO EXCESS OBSERVED:

  12. SEARCH FOR POINT SOURCES • Several strategies in the search for point sources: • Diffuse flux of neutrinos with no time-space correlations. Focus on E-2 spectrum • calculate upper limit on high energy tail of atmosphericνμ • optimize selection with attention to background(s) rejection • multi-flavor (muon tracks + cascades) • Spacial correlation with steady objects • Search for clusters of events (w. or w.o. catalogue) • Stacking of known point source candidates (paper in preparation) • Space and/or time correlation with transient phenomena • known active flary periods of TeV gamma sources • time window-rolling search of signal excess over background

  13. signal: background: DIFFUSE SEARCH Analyses optimized for nm, : reduced sensitivity to ne and nt | All-flavour • UHE: En > P eV: • Earth opaque • Search in the upper hemisphere and close to the horizon • Bright events: many hit OMs with several hits/OM •  Energy -related variables best handle of analysis • HE: TeV < En < PeV: • Use directionality + energy-related • variables to reject atm m background • Search confined to up-going tracks • Use high-quality tracks • Cascades: TeV < E < PeV • 4p search • Background: brehmm. from down-going muons Limit from data sample 1997. 131 d lifetime: Assuming a E-2 flux (1 PeV < En < 3 EeV) and ne:nm:nt = 1:1:1 E2Fm(E) < 8.4 x 10-7 GeV cm-2 s-1 sr-1 Sensitivity from data sample 2000-03. 807d lifetime: Assuming a E-2 flux (13 TeV < En < 3.2 PeV) and ne:nm:nt = 1:1:1 E2Falln(E) < 9.5 x 10-8 GeV cm-2 s-1 sr-1 Limit from data sample 1997. 131 d lifetime: Assuming a E-2 flux (1 PeV < En < 3 EeV) and ne:nm:nt = 1:1:1 E2Falln(E) < 9.9 x 10-7 GeV cm-2 s-1 sr-1 Sensitivity from data sample 2000. 174 d lifetime: Assuming a E-2 flux (0.2 PeV < En < 2 EeV) and ne:nm:nt = 1:1:1 E2Falln(E) < 4.2 x 10-7 GeV cm-2 s-1 sr-1 Limit from data sample 1997. 131 d lifetime: Assuming a E-2 flux (50 TeV < En < 3 PeV) and ne:nm:nt = 1:1:1 E2Falln(E) < 9.8 x 10-6 GeV cm-2 s-1 sr-1 Sensitivity from data sample 2000. 174 d lifetime: Assuming a E-2 flux (50 TeV < En < 5 PeV) and ne:nm:nt = 1:1:1 E2Falln(E) < 8.6 x 10-7 GeV cm-2 s-1 sr-1

  14. 6 7 DIFFUSE SEARCHES: SUMMARY all-flavor limits AMANDA 1: B10, 97, ↑μ 2: A-II, 2000, unfold. 3: A-II, 2000, cascade 4: B10, 97, UHE 6: A-II, 2000, UHE sensit. 7: A-II, 2000-03 ↑μ sensit. Baikal 5: 98-03, casc. 1:1:1 flavor flux ratio Limits for other flux predictions: Cuts optimized for each case. Expected limit from a given model compared with observed limit. Some AGN models excluded at 90% CL : Szabo-Protehoe 92 Stecker, Salamon. Space Sc. Rev. 75, 1996 Protehoe. ASP Conf series, 121, 1997

  15. time d=0o  (horizontal) d declination d=90o  (vertical) SEARCH FOR CLUSTERS OF EVENTS IN THE NORTHERN SKY • Search for excesses of events compared to the background from: • the full Northern Sky • a set of selected candidate sources • Cuts optimized in each declination band • Require good pointing resolution • (good quality events) • Background estimated from exp. data with randomized α (i.e. time) • Sensitivity  flat up to horizon • Significant improvement w.r.t. first analysis with AMANDA-B10 Average upper limit = sensitivity (δ>0°) (integrated above 10 GeV, E-2 signal) AMANDA-B10 average flux upper limit [cm-2s-1] AMANDA-II sin(d) Declination averaged sensitivity for a En-2 spectrum and En > 10 GeV lim  0.6·10-8cm-2s-1

  16. SEARCH FOR CLUSTERS OF EVENTS IN THE NORTHERN SKY Event selection optimized for both dN/dE ~ E-2 and E-3 spectra Data from 2000-2003 (807 days) 3369 n from northern hemisphere 3438 n expected from atmosphere Maximum significance: 3.4 s Assess statistical significance using random sky maps: Probability of a background Fluctuation: 92%

  17. On-Source Off-Source SEARCH FOR CLUSTERS OF EVENTS FROM KNOWN OBJECTS Selected objects and full scan of the northern sky: No statistically significant effect observed SensitivityFn/Fg~2 for 200 days of “high-state” and spectral results from HEGRA Crab Nebula: The chance probability of such an excess (or higher) given the number of trials is 64% Preliminary … out of 33 Sources Systematic uncertainties under investigation

  18. POINT SOURCE SEARCH: TIME WINDOW EXCESS Enhance the detection chance by using the time information: Search for neutrino flares without a-priori hypothesis on their time of occurrence sliding window Search for excesses in time-sliding windows: galactic objects: 20 days extra-galactic objects: 40 days events time Preliminary … out of 12 Sources → no statistically significant effect observed

  19. SEARCH FOR ’s CORRELATED WITH GRBs Low background analysis due to both space and time coincidence! • Catalogues: BATSE+IPN3 • Several search techniques: • coincidence with T90 • precursor (110s before T90) • cascades (all flavour, 4p) • -coincident with T90 • -rolling time window • (no catalogue) • Bckg. Stability required within ±1 hour from burst • Further searches: rolling search (without temporal/spacial constrains) • Eν2Φν < 6.7x 10-6 GeV cm-2 s-1 sr-1

  20. Combined 1997-99 data sets: Searches from the center of the Earth 2001 data set: Search from the Sun SEARCH FOR DM CANDIDATES IN THE SUN/EARTH • Wm 20%, Wb  5% •  non-baryonic matter •  MSSM: c candidate • accumulating over cosmological time in the Sun/Earth. Pair-wise annihilation at its center: • and consider (MC=DarkSusy) • (soft channel) • (hard channel) • for various c masses (50-5000 GeV) Sun analysis possible due to improved reconstruction capability for horizontal tracks in AMANDA-II compared with B10.

  21. SEARCH FOR SNe EXPLOSIONS IN THE GALAXY • Burst of low-energy • (MeV)neutrinos from • core collapse • supernovae • increase in • detector noise rate • due to • ne+e- e- + X • Low energy O(ev) • e- tracks: no pointing • Monitor noise of • subset of stable OMs • Special DAQ: count • rates in 10 s • 92% coverage of the • Milky Way • AMANDA part of • SNEWS alert network Crab Nebula Sun Cassiopeia. A Cygnus-X1 LMC Approximate AMANDA horizon SMC 90 000 light years

  22. The IceCube observatory: IceCube+IceTop 1200 m • Surface array: IceTop • 80 stations air shower array. • (one per IceCube string) • 2 tanks (2 DOMs each) per station • 125 m grid, 1 km2 at 690 g/cm2 • Ethreshold ~ 300 TeV for > 4 stations in coincidence IceTop IceCube Deep ice array: IceCube • Digital readout technology (D-OMs) • 80 strings / 60 DOM’s each • 17 m DOM spacing • 125 m between strings • hexagonal pattern over 1 km2x1 km

  23. THE SITE South Pole road to work Station facilities AMANDA IceCube 1500 m Amundsen-Scott South Pole station 2000 m [not to scale]

  24. e  e  “cascade” Eµ=6 PeV En = 375 TeV ~300m @ Et = 1 PeV IceCube: an All-Flavor Neutrino Telescope m m 1 year sensitivity a point E2·dF/dE flux IceCube will be able to identify •  tracks from  for E > 100 GeV • cascades from e for E > 10 TeV •  for E > 1 PeV Background mainly downgoing cosmic ray  (bundles) (+ uncorrelated coincident 's) - exp. rate at trigger level ~1.7 kHz - atm.  rate at trigger level ~300/day Em < 1 PeV: focus on the Northern sky E > 1 PeV: sensitive aperture increases w. energy  full sky observations possible

  25. IceTop Stations with DOMs – January 2004 Digitized muon signals from DOMs signal, freeze control, temperature control cables Amplitude (ATWD counts) vs time (ns) power cable

  26. IceCube First String: January 2005 27.1, 10:08: Reached maximum depth of 2517 m, reversed direction, started to ream up 28.1, 7:00: drill head and return water pump are out of the hole, preparations for string installation start 7:52: Handover of hole for deployment 9:15: Started installation of the first DOM (DOM 60) 12:06: 10th DOM installed 22:36: 60th DOM installed Typical time for DOM installation:12 min 22:48: Start drop 29.1, 1:31: String secured at depth of 2450.80 m 20:40: First communication to DOM

  27. An IceCube-IceTop event

  28. Outlook • A wealth of results from AMANDA-B10 and AMANDA-II on several physics topics • Results from combined analysis using several years ’00-’03 (more on the way) • No extraterrestial neutrinos observed yet • Sensitivity reaching the level of current predictions of n production in AGN. • Some models already excluded @ 90%CL • Digitized readout since 2003: waveform resolution • First IceTop station deployed on Jan. 2004 • First IceCube string deployed on Jan. 2005 • First IceCube-IceTop and IceCube-AMANDA events seen • IceCube/IceTop will significantly improve astrophysics and cosmic rays measurements in energy range and resolution

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