The AMANDA and IceCube 高エネルギーν天文学：宇宙探査の窓 Physics Motivation AMANDA detector Recent Experimental Results IceCube Project overview and Status EHE Physics Example: Detection of GZK neutrinos 吉田　滋 (千葉大学理)

You cannot expect too many n! p g (p,n) p 2g TeV/EGRET observations !! Cosmic Ray observations! m n Synchrotron cooling e n n You cannot expect too high energies

Theoretical bounds Suppressed by Synchrotron Cooling MPR W&B DUMAND test string FREJUS NT-200 MACRO opaque for neutrons MPR neutrons can escape atmospheric  W&B Mannheim, Protheroe and Rachen (2000) – Waxman, Bahcall (1999)  derived from known limits on extragalactic protons + -ray flux

EHE(Extremely HE) n Synchrotron cooling of m … Production sites with low B Intergalactic space!! GZK Production Z-burst Topological Defects/Super heavy Massive particles

Shall we Dance?

Amundsen-Scott South Pole Station Where are we ? South Pole Dome road to work AMANDA Summer camp 1500 m Amundsen-Scott South Pole Station 2000 m [not to scale]

AMANDA-B10 10 strings 302 OMs AMANDA-II 19 strings 677 OMs (inner core of AMANDA-II) 10 strings 302 OMs Data years: 1997-99 AMANDA-II 19 strings 677 OMs Trigger rate: 80 Hz Data years: >=2000 “Up-going” (from Northern sky) “Down-going” (from Southern sky) Optical Module PMT looking downward PMT noise: ~1 kHz

Event detection in the ice O(km) long m tracks South Pole ice: the most transparent natural medium ? event reconstruction by Cherenkov light timing ~15 m <labs> ~ 110 m @ 400 nm <lsca> ~ 20 m @ 400 nm AMANDA-II m tracks pointing error : 1.5º - 2.5º σ[log10(E/TeV)] : 0.3 - 0.4 coverage : 2p Cascades (particle showers) pointing error : 30º - 40º σ[log10(E/TeV)] : 0.1 - 0.2 coverage : 4p cosmic rays (+SPASE) combined pointing err : < 0.5º σ[log10(E/TeV)] : 0.06 - 0.1 Nucl. Inst. Meth. A 524, 169 (2004) cascades a neutrino telescope Qmn0.65o(En/TeV)-0.48 (3TeV<En<100TeV) Longer absorption length → larger effective volume

Atmospheric n's in AMANDA-II  neural network energy reconstruction  regularized unfolding PRELIMINARY measured atmospheric neutrino spectrum  spectrum up to 100 TeV  compatible with Frejus data presently no sensitivity to LSND/Nunokawa prediction of dip structures between 0.4-3 TeV In future, spectrum will be used to study excess due to cosmic ‘s 1 sigma energy error We can also say a few words about localy created nus we have improvement compared to B10, better reco and energy measurement...sufficient statistics to do unfolding in statistically meaningfull way....

Oscillation in AMANDA‘s range SuperK values: Dm² = 2,4 * 10-3 eV² sin²(2QMix) = 1,0 1 TeV 100 GeV 50 GeV 30 GeV Problem: lower energy threshold ~ 100 GeV - 1 TeV P( nm  nm ) 10 GeV positive identification not possible flight length / km 110° 180°

Oscillation in AMANDA‘s range Variation of Dm² (En =100GeV) 10-3 eV² significant oscillation in AMANDA‘s range exclusion regions in sin²(2Q)-Dm² -plane 2,4 * 10-3 eV² 10-2 eV² P( nm  nm ) 2,8 * 10-2 eV² flight length / km 110° 180°

Excess of cosmic neutrinos? Not yet ... talk HE 2.3-4 Excess of cosmic neutrinos? Not yet ... .. for now use number of hit channels as energy variable ... muon neutrinos (1997 B10-data) accepted by PRL cascades (2000 data) „AGN“ with 10-5 E-2 GeV-1 cm-2 s-1 sr-1 cuts determined by MC – blind analyses !

The highest energy event (~200 TeV) 300 m

Theoretical bounds and future DUMAND test string FREJUS NT-200 MACRO opaque for neutrons MPR NT-200+ AMANDA-II IceCube AMANDA-97 AMANDA-00 neutrons can escape atmospheric  W&B Mannheim, Protheroe and Rachen (2000) – Waxman, Bahcall (1999)  derived from known limits on extragalactic protons + -ray flux

n telescope : point source search Maximum significance 3.4 s compatible with atmospheric n ~92% Preliminary 2000-2003 3369 n from northern hemisphere 3438 n expected from atmosphere Search for clustering in northern hemisphere compare significance of local fluctuation to atmospheric n expectations un-binned statistical analysis no significant excess  also search for neutrinos from unresolved sources

Extend this information to the AMANDA exposure time, caveat: g-rays observation are generally very short and for limited periods… Tibet data quite cover the (HEGRA) High period Second Assumption: use X-ray data to define relative High/Low time for the whole time 2000/2003 AMANDA observational time High state/total time: ~210/807 or also ~1 year/4 years of AMANDA exposure

can be compared to our best upper limit (sensitivity shown here) Low state: can be compared to our best upper limit (sensitivity shown here) about factor 2 Fit of the measured spectrum from HEGRA (Low) Allowed range for the emitted flux AMANDA sensitivity Correction for extra-galactic g absorption¶: TeV g-ray spectra are modified by red-shift dependent absorption by intergalactic IR-UV background ¶O.C.De Jager & F.W.Stecker, Astrophy.J. 566 (2002), 738-743

Current best estimate High state: can be compared to the AMANDA sensitivity for ~ 200 days of live time (1 year exposure) Sensitivity n/g~1 BUT without accounting for oscillations (a factor 2 in the n flux should be added!!) Current best estimate Fit of the measured spectrum from HEGRA (Low) Allowed range for the emitted flux AMANDA sensitivity (NB: this under the assumption that the source would show ~ 800 days of high state!)

Search for  correlated with GRBs -1 hour +1 hour 10 min Blinded Window Background determined on-source/off-time Background determined on-source/off-time Time of GRB (Start of T90 ) Low background analysis due to space and time coincidence! PRELIMINARY Year Detector NBursts NBG, Pred NObs Event U.L. 1997 B-10 78 (BT) 0.06 2.41 1998 94 (BT) 0.20 2.24 1999 96 (BT) 2000 A-II (2 analyses) 44 (BT) 0.83/0.40 0/0 1.72/2.05 97-00 B-10/A-II 312 (BT) 1.29 1.45 24 (BNT) 0.24 2.19 46 (New) 0.60 1.88 114 (All) 1.24 1.47 GRB catalogs: BATSE, IPN3 & GUSBAD Analysis is blind: finalized off-source (± 5 min) with MC simulated signal BG stability required within ± 1 hour Muon effective area (averaged over zenith angle)  50,000 m2 @ PeV (BT = BATSE Triggered BNT = BATSE Non-Triggered New = IPN & GUSBAD) 97-00 Flux Limit at Earth*: E2Φν≤ 4·10-8 GeV cm-2 s-1 sr-1 *For 312 bursts w/ WB Broken Power-Law Spectrum (Ebreak= 100 TeV, ΓBulk= 300)

WIMP annihilations in the center of Earth Sensitivity to muon flux from neutralino annihilations in the center of the Earth: PRELIMINARY Muon flux limits Look for vertically upgoing tracks Eμ > 1 GeV NN optimized (on 20% data) to - remove misreconstructed atm. μ - suppress atmospheric ν - maximize sensitivity to WIMP signal Combine 3 years: 1997-99 Total livetime (80%): 422 days Disfavored by direct search (CDMS II) Soft channel: b-bbar; Hard channel: WW pairs New solar system WIMP diffusion model -> more realistic neutralino velocity distribution (Lundberg&Edsjoe) Detection threshold (mu): ~50GeV (extrapolate to get limits for E>1 GeV) No WIMP signal found Limit for “hardest” channel:

WIMP annihilations in the Sun Increased capture rate due to addition of spin-dependent processes Sun is maximally 23° below horizon Search with AMANDA-II possible thanks to improved reconstruction capabilities for horizontal tracks Exclusion sensitivity from analyzing off-source bins 2001 data 0.39 years livetime PRELIMINARY Muon flux limits Eμ > 1 GeV IceCube best case = 10 calendar years, only atm nu bgr, no PMT noise MESSAGE: at least for the Sun we have a chance to compete with direct searches No WIMP signal found Best sensitivity (considering livetime) of existing indirect searches using muons from the Sun/Earth

AMANDA as supernova monitor AMANDA-II AMANDA-B10 IceCube 30 kpc AMANDA as supernova monitor ~MeV Bursts of low-energy (MeV) νe from SN ► simultaneous increase of all PMT count rates (~10s) Since 2003: SNDAQ includes all AMANDA-II channels Recent online analysis software upgrades can detect 90% of SN within 9.4 kpc less than 15 fakes/year  can contribute to SuperNova Early Warning System (with Super-K, SNO, Kamland, LVD, BooNE) coverage B10: 70% of Galaxy A-II: 95% of Galaxy IceCube: up to LMC Analysis of 200X data in progress

The IceCube Neutrino Telescope Project overview and Status EHE Physics Example: Detection of GZK neutrinos

Who are we ? Bartol Research Inst, Univ of Delaware, USA Pennsylvania State University, USA University of Wisconsin-Madison, USA University of Wisconsin-River Falls, USA LBNL, Berkeley, USA UC Berkeley, USA UC Irvine, USA Univ. of Alabama, USA Clark-Atlanta University, USA Univ. of Maryland, USA IAS, Princeton, USA University of Kansas, USA Southern Univ. and A&M College, Baton Rouge Chiba University, Japan University of Canterbury, Christchurch, New Zealand Universidad Simon Bolivar, Caracas,Venezuela Université Libre de Bruxelles, Belgium Vrije Universiteit Brussel, Belgium Université de Mons-Hainaut, Belgium Universität Mainz, Germany DESY-Zeuthen, Germany Universität Wuppertal, Germany Uppsala Universitet, Sweden Stockholm universitet, Sweden Kalmar Universitet, Sweden Imperial College, London, UK University of Oxford, UK Utrecht University, Utrecht, NL

First year deployment (Jan 2005) 4 IceCube strings (240 OMs) IceTop 160 tanks frozen-water tanks 2 OMs / tank First year deployment (Jan 2005) 4 IceCube strings (240 OMs) 8 IceTop Tanks (16 OMs) IceTop IceCube AMANDA IceCube 80 strings 60 OMs/string 17 m vertical spacing 125 m between strings IceTop Tank deployed in 2004 10” Hamamatsu R-7081

Road to South Pole 9 hours 6 hours

How EHE events look like The typical light cylinder generated by a muon of 100 GeV is 20 m, 1PeV 400 m, 1EeV it is about 600 to 700 m. Eµ=10 TeV ≈ 90 hits Eµ=6 PeV ≈ 1000 hits

Digital Optical Module (DOM) HV Base “Flasher Board” Main Board (DOM-MB) 10” PMT 13” Glass (hemi)sphere

Capture Waveform information (MC) nt E=10 PeV String 1 String 2 String 3 String 4 String 5 ATWD 300MHz 14 bits. 3 different gains (x15 x3 x0.5) Capture inter. 426nsec 10 bits FADC for long duration pulse. Events / 10 nsec 0 - 4 µsec

World-wide DOM collaboration Stockholm Electronics Assembly Calibration Screening. Wisconsin LBL DESY Chiba

Photomultiplier: Hamamatsu R7081-02 (10”, 10-stage, 1E+08 gain) Selection criteria (@ -40 °C) Noise < 300 Hz (SN, bandwidth) Gain > 5E7 at 2kV (nom. 1E7 + margin) P/V > 2.0 (Charge res.; in-situ gain calibration) Notes: Only Hamamatsu PMT meets excellent low noise rates! Tested three flavors of R7081.

SPE Charge Spectrum

Setup photo This is the actual picture of the setup. Laser, chamber, IceCube PMT, backward and forward monitor PMT, and the enegy meter. (and Kotoyo and my hand)

Expected Data Rates PMT noise rate of 1 kHz is expected "Scintillation" of glass introduces correlations! Two DOMs/twisted pair ( $, kg, flights,...) Rates/pair (bits/s) for coincidence mode (with zero suppression and compression) None: 18 kbytes/s x 2 x 10 = ~400 kbits/s Soft: 6-8 kbytes x 2 x 10 = ~160 kbits/s Hard: <1 kbyte/s x 2 x 10 = ~20 kbits/s Demonstrated in the lab: 1 Mbit/s

IceCube Software

ROMEO – Optical detector simulator ROOT Ttask base Full detector simulation

JULIeT – Particle Propagator Monte-Carlo Simulation m , n , t Numerical Calculation

Angular resolution as a function of zenith angle Waveform information not used. Will improve resolution for high energies ! 0.8° 0.6° above 1 TeV, resolution ~ 0.6 - 0.8 degrees for most zenith angles

Energy Spectrum Diffuse Search Blue: after downgoing muon rejection Red: after cut on Nhit to get ultimate sensitivity

HEAPA 2004 Project status Startup phase has been approved by the U.S. NSB and funds have been allocated. 100 DOMs are produced and being tested this year. Assembling of the drill/IceTop prototypes is carried out at the pole last season. Full Construction start in 04/05 (this year!!); takes 6 years to complete. Then 16 strings per season, increased rate may be possible.

Right now at the pole

GZK EHEn detection What is the GZK mechanism? HEAPA 2004 GZK EHEn detection What is the GZK mechanism? EHE n/m/t Propagation in the Earth Expected intensities at the IceCube depth Atmospheric m – background Event rate

mN mX e+e- UHE (EeV or even higher) Neutrino Events Arriving Extremely Horizontally Needs Detailed Estimation Limited Solid Angle Window (srNA)-1 ~ 600 (s/10-32cm2) -1(r/2.6g cm-3) -1 [km] Involving the interactions generating electromagnetic/hadron cascades mN mX e+e-

ne nm nt m t p ne nm nt m t p e/g e/g Products Incoming Decay Decay Weak Weak nm Weak Weak nt Weak Weak Incoming e/g Cascades Decay Decay Weak Pair/decay Bremss m Pair Pair PhotoNucl. Pair Bremss Decay DecayPair Decay Decay Decay Decay Weak t Pair PhotoNucl. p Cascades

Atmospheric muon! – a major backgrond But so steep spectrum Upward-going Downward going!! Atmospheric muon! – a major backgrond But so steep spectrum HEAPA 2004

Down-going events dominate… Atmospheric m is strongly attenuated… 11000m Up Down 2800 m 1400 m HEAPA 2004

Flux as a function of energy deposit in km3 dE/dX~bE DE~DXbE

Uncertainty in Prompt Lepton Cross Sections AMANDA II (neutrinos) The uncertainty ~3 orders Need for accelerator data extrapolation Crossover between 40TeV and 3 PeV ZhVd

Constraining Charm Neutrino models by analysis of downgoing Muon Data AMANDA II (neutrinos) Very preliminary sensitivity on ZHV-D model Systematics to be well understood Potential to set a more restrictive limit than neutrino diffuse analyses ZHVd AMANDA II (muons)

IceCube EHE n Sensitivity 90% C.L. for 10 year observation Published in Phys. Rev. D S.Yoshida, R.Ishibashi, H,Miyamoto, PRD 69 103004 (2004)

IceTop : EeV detection n m Threshold ~ 1018 eV to veto this background Penetrating muon bundle in shower core Incident cosmic-ray nucleus Threshold ~ 1018 eV to veto this background n Potential to reject this background for EeV neutrinos by detecting the fringe of coincident horizontal air shower in an array of water Cherenkov detectors (cf. Ave et al., PRL 85 (2000) 2244, analysis of Haverah Park) back

Grand Summary RICE Fly‘s Eye AGASA NT-214 AUGER nt OWL, EUSO Macro Frejus Baikal Amanda-B NT-214 AMANDA-II & ANTARES AUGER nt IceCube & km3 in sea OWL, EUSO Courtesy: Learned & Mannheim; Spiering