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Carlos de los Heros Division of High Energy Physics Uppsala University CRIS04

RESULTS FROM AMANDA. Carlos de los Heros Division of High Energy Physics Uppsala University CRIS04 Catania, Italy, May 31-June 4. The AMANDA/ICECUBE Collaborations. Bartol Research Institute UC Berkeley UC Irvine Pennsylvania State UW Madison UW River Falls LBNL Berkeley

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Carlos de los Heros Division of High Energy Physics Uppsala University CRIS04

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  1. RESULTSFROMAMANDA Carlos de los Heros Division of High Energy Physics Uppsala University CRIS04 Catania, Italy, May 31-June 4

  2. The AMANDA/ICECUBE Collaborations Bartol Research Institute UC Berkeley UC Irvine Pennsylvania State UW Madison UW River Falls LBNL Berkeley U. Simón Bolivar, Caracas VUB-IIHE, Brussel ULB-IIHE, Bruxelles Université de Mons-Hainaut Imperial College, London DESY, Zeuthen Mainz Universität Wuppertal Universität Stockholm Universitet Uppsala Universitet Kalmar Universitet South Pole Station 150 members +University of Maryland, US Clark-Atlanta University, US Southern University, US IAS, Princeton, US University of Alabama, US University of Oxford, UK University of Utrecht, NL Chiba University, Japan U. of Canterbury, Christchurch, NZ as ICECUBE members

  3. NEUTRINO ASTRONOMY • Cosmic rays @ >>TeV exist  acceleration sites must sit somewhere • SNe remnants • 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. O(km) long muon tracks  12 m THE AMANDA DETECTOR determination of the trajectory by Cherenkov light timing 19 strings 677 PMTs trigger rate: 80 Hz PMT noise rate: 1 kHz • need up/down rejection  10-6 •  background from atmospheric muons

  5. ~ 5 m ALL FLAVOUR DETECTION Electromagnetic and hadronic cascades •  : oscillation + regeneration at PeV •  important • no EM / hadronic cascade differentiation • (even if slightly different shape and lower • light output for hadronic cascades)

  6. TWR UPGRADE • Transient Waveform Recorder system • installed between the 2001 and 2004 • campaigns • Increased OM dynamic range x ~100 • Increased 1pe detection efficiency • Virtually dead-time free • Manageable trigger rate: ~150 Hz • (majority 18) • Possibility of using software trigger • Physics benefits: • Improved angular resolution • Improved energy resolution • UHE/EHE physics

  7. THE SITE geographic South Pole AMANDA 2km deep

  8. DETECTOR MEDIUM: ICE PROPERTIES ice optical parameters: labs ~ 110 m @ 400 nm lscatt ~ 20 m @ 400 nm in-situ light sources atmospheric muons

  9.  effective area (schematic): -interaction in earth, detector response En 2 100 GeV 100 TeV 100 PeV DETECTOR CAPABILITIES • muons: • directional error: 1.5° - 2.5° • s(log(DE/E)):0.3 – 0.4 • coverage: 2 • showers: (e±,  , neutral current) • zenith error: 30° - 40° • s(log(DE/E)): 0.1 – 0.2 • (5TeV < E < 5 PeV) • coverage: 4 • primary cosmic rays:(+ SPASE2) • energy resolution:0.07 – 0.10 5m2 3 cm2

  10. AMANDA can operate in very different energy regimes Energy range analysis production site(s) ~MeV SN n Supernovae GeV - ~TeV atm n atmosphere Dark matter Sun/Earth TeV - PeV diffuse AGN, GRB… cascades point sources PeV – EeV UHE AGN, TD… > EeV EHE ? Agreed collaboration strategy: Analyses are done ‘blind’. cuts optimized on a % of data or on a time-scrambled data set. (except for SN searches where analysis is based on detector noise rate monitoring)

  11. AMANDA PHYSICS TOPICS Cosmology / Particle Physics / Astrophysics • primary CR spectrum: •  atmospheric neutrinos (also calibration/background of Amanda) •  CR composition (with surface detector SPASE-2) • CR origin (acceleration sites: AGN, GRBs) •  extra-terrestrial flux (diffuse / punctual / transient) @ >TeV energies • Dark matter / exotic particles: neutralinos, magnetic monopoles, extra dim. • WIMP’s signature: Excess from the Sun/Earth’s center direction • heavy and slow particles • Topological defects:extra-terrestrial UHE diffuse flux • SN monitor of the Milky Way •  low energyEM cascades (global noise increase throughout AMANDA)

  12. 10-5 E-2 GeV-1 cm-2 s-1sr-1 atm. Exp. cut TeV-PeV DIFFUSE FLUX • data sample ’97: 109 evts • data 2000 analysis on the way • hit channel multiplicity as energy indicator • cuts optimized for best sensitivity • Above optimal cut Nch>54: • Nobs = 3 evts • Natm n= 3.06 ± 25%norm± ~35% sys NO EXCESS OBSERVED PRL 90 (2003), 251101 E2nm(E) < 8.4 10-7 GeV cm-2 s-1 sr-1 assuming a E-2 flux (6 TeV < En < 1 PeV) :

  13. TeV-PeV DIFFUSE FLUX: LIMITS Comparison to other experimental E-2 limits Limits for other flux predictions: Nch cut optimized for each case. Expected limit from a given model compared with observed limit. Some AGN models excluded at 90% CL (marked as X below) Stecker et al, Phys Rev Lett 66 1991, 69 1992 Szabo-Protehoe 92 X X Stecker, Salamon. Space Sc. Rev. 75, 1996 Protehoe. ASP Conf series, 121, 1997 X

  14. HE DIFFUSE FLUX (cascades) • 2000 data sample, 197 days lifetime. • 1.2x109 events @ trigger level • sim. BG: • atm. muons (920 d) • atm. neutrinos • After optimized cuts : • Nobs = 1 evts • Natm m= 0.90 +0.69–0.43 • Natm n= 0.06+0.09-0.04± 25%norm no earth propagation effects nt nm ne

  15. HE DIFFUSE FLUX (cascades): LIMITS • sensitivity to all three flavors • assuming a E-2 flux: • for specific models: • some AGN core-production models discarded @ 90% CL • (dashed in figure) E2all (E) < 0.86·10 – 6GeV cm-2 s-1 sr-1 (e::=1:1:1) paper submitted to Phys. Rev. D From data sample ’97, 130 days lifetime (5 TeV < En < 300 TeV): E2all (E) < 9.8·10– 6 GeV cm-2 s-1 sr-1 (e::=1:1:1) E2ne(E) < 6.5·10– 6 GeV cm-2 s-1 sr-1 Phys. Rev. D67, 2003

  16. n m 10-6 E-2 Neural Net parameter for neutrino vs. atm muon separation UHE neutrinos Simulated UHE event • En > 1016 eV: Earth opaque • Search in the upper hemisphere • and close to horizon • Increased n-Xsection • (but uncertainties at these energies) • Long m tracks (> 10 Km) • Bright events low atm m background • Energy -related variables best handle of analysis Experiment CORSIKA MC

  17. assuming a E-2 flux (1 PeV < En < 3 EeV) : NO EXCESS OBSERVED E2all (E) < 1.510-6 GeV cm-2 s-1 sr-1 (e::=1:1:1) paper in progress UHE neutrinos: Limits PRELIMINARY Data sample: 1997. 131 d livetime Average all angles Nobs = 5 evts Nbck = 4.6 ± 36% evts Horizontal events n effective area vs log En

  18. POINT SOURCE SEARCHES Search for an event excess in the northern sky  grid: sky subdivided into 300 bins ~7°x7° (zenith dependent) between 0o < d < 85o Eff. area vs m energy (2000 data) • cuts optimized in each declination band • sensitivity  flat up to horizon, • (in average 4 times better than 1997 analysis, PRELIMINARY 2 independent analyses in 2000 Sensitivity X 10-7 GeV-1 cm-2 s-1 Astrophys. J. 583, 2003) zenith X1.8 improvement by combining 2 yrs of data. Work in progress

  19. POINT SURCE SEARCHES: FLUX LIMITS below horizon: mostly atmospheric ‘s (this means northern sky) above horizon:atm m events 2000 data: upper limits in units of 10-7cm-2s-1 En>10 GeV, assumed E-2 spectral shape 699 neutrino events observed from below the horizon (2000 data) <10% non-neutrino background for >5° no clustering observed: no evidence for point sources declination averaged sensitivity (integrated above 10 GeV) : lim  2.3·10-8 cm-2s-1 Phys. Rev. Lett. 92, 071102,2004

  20. POINT SURCE SEARCHES: FLUX LIMITS Upper limits in units of 10-8cm-2s-1 for an assumed E-2 neutrino spectral shape integrated above En=10 GeV on some selected sources:

  21. SEARCH FOR CORRELATED WITH GRBs 10 min Low background analysis due to both space and time coincidence! PRELIMINARY • Catalogs: • BATSE, IPN3 • Analysis is blind: finalized off-source • (±5 min) with MC signal • <20° + other event quality parameters • BG stability required within ±1 hour • from burst • m effective area 50000m2 (BT = BATSE Triggered BNT = BATSE Non-Triggered New = IPN & GUSBAD) 97-00 Flux Limit at Earth: E2Φν≤4x10-8GeV cm-2 s-1 sr-1 For 312 bursts w/ Broken Power-Law Spectrum (Ebreak=100 TeV, Γ=300)

  22. SPASE/AMANDA: CR composition SPASE (scintillator array @ 3000m, ~685 g cm-2) 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 369m AMANDA 1500m Iron Proton AMANDA (number of muons) ln(A) log(E/PeV) SPASE-2 (number of electrons)

  23. SPASE/AMANDA: CR composition (cont.) • Combined SPASE-AMANDA ‘detector’: • Probes hadronic (m) and EM (e) energy in 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 Amanda-B10 / Spase-2 CR composition: paper accepted in Astropart. Phys.

  24. OUTLOOK • First results from AMANDA-II published (2000 data) • Amanda-II detector shows greatly improved capabilities • Sensitivity at the level of current predictions of n production in AGN. Some models excluded @ 90CL • combined analysis ’00-’03 on its way • papers from analysis of 97-2000+ data in progress • digitized readout since 2003: waveform resolution • ice description mature: being fully implemented in MC • first IceCube strings in 2004/05 antarctic season

  25. And what I did not talk about…

  26. TEST BEAM: ATMOSPHERIC NEUTRINOS Atmospheric muons and neutrinos: AMANDA test beams PRELIMINARY • Neural network energy reconstruction • regularized unfolding •  spectrum up to 100 TeV • First spectrum beyond • 1 TeV. Matches Frejus data at lower energies Possible to use the energy spectrum to study excess due to cosmic ‘s

  27. WIMPS FROM THE SUN/EARTH cc qq, WW, ZZ, HH n Sun analysis possible due to improved reconstruction capability for horizontal tracks in AMANDA-II compared with B10 Current results from 2001 data set Combined 1997-99 data sets for Earth WIMP searches. PRELIMINARY 2001 data Best limits from existing indirect searches

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