Vrije Universiteit Brussel, Belgium

B.Baret Vrije Univertsiteit Brussel

Vrije Universiteit Brussel, Belgium

The AMANDA – IceCube telescopes&

Dark Matter searches

B. Baret on behalf of the IceCube collaboration

[email protected]

http://amanda.uci.edu http://icecube.wisc.edu

6th Cracow Epiphany Conference


Physics Motivations and Goals

AMANDA

IceCube

Attractive astronomical messengers:•Transparent Universe (≠)•Travel in straight line (≠p)•Produced in hadronic accelerators ?

Study of:Sources:

AGNs, SNRs, GRBs...-physics (atmospheric

production):Oscillations, cross-sections..

“new” physics:WIMPS, decoherence, monopoles...


The IceCube collaborationUSA: 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

Sweden: Uppsala Universitet Stockholm Universitet

UK: Imperial College, London Oxford University

Netherlands: Utrecht University

Belgium: Université Libre de Bruxelles Vrije Universiteit Brussel Universiteit Gent Université de Mons-Hainaut

Germany: Universität Mainz DESY-Zeuthen Universität Dortmund Universität Wuppertal Humboldt Universität, Berlin

Japan: Chiba University

New Zealand: University of Canterbury


Where are we ?

Amundsen-Scott South Pole Station

Here! (South pole)

IceCube

Amanda

North

Technically North also


Detection principle

O(km) long tracks

O(10m) cascades e,

South Pole Ice properties (@400nm):

Scattering:~20m Pointing res. (~2° , casc. ~35°)

Absorption:~110m Effective volume

Background (x E.T. events/year):atmospheric O(109)atmospheric O(103)

E.T. atm.

p


Layout

IceCube:

1km x1 km² instrumented volume

4800 Digital Optical Modules (DOMs) on 80 strings

IceTop(air shower array):

1km² instrumented area

160 surface water tanks with 2 DOMs each

Amanda:Ø=200m, h=500m (0.02 km³)Amanda B-10:

302 Optical Modules (OMs) on 10 strings (97-99)

Amanda II:677 OMs on 19 strings (00->)


IceCube Deployment

January 2005:First string deployed60 DOMs installed (and working!)

Hot water drilling:2450 m deepstraight within 1m35-40 hrs per hole

Deployment:2 more strings up to nowExpected completion in 2010


IceCube First Events!

IceTop – IceCube

String 21

Down going IceTop tanks


all-flavor limitsνμ (B10 1yr)

νμ (A-II 4yr)

νμ (A-II 1yr) νe+νμ+ντ (cascades A-II 1yr)

νe+νμ+ντ (UHE B10 1yr)

νe (cascades B10 1yr)

νe+νμ+ντ (UHE A-II 1yr)

Sensitivity and limits

Icecube (1yr)

WB bound

Limit

Sensitivity

Diffuse search

ave

rag

e fl

ux

up

per

lim

it [

cm-2s-1

]

sin

AMANDA-B10

AMANDA-II

IceCube 1/2 year

*

Steady point sources sensitivity:

E-2 flux hypothesis


Point sources

Sky map (00'-03')

Significance maps

No point source detected so far...

3329

real sky

scrambled skyno source


Neutralino as dark matter candidate

Cosmological observationsm ~ 0.30

b ~ 0.05

Minimal Supersymmetric Standard ModelPR conserved LSP stable = neutralino

interacts weakly = GeV-TeV mass = dark matter??? stable

dark, non-baryonic matter


Neutralino capture by Sun and Earth

Sun – direct capture from galactic DM halo

Earth – capture by gravitational diffusion and weak scattering


Which WIMP signal

Neutralino-induced neutrinos

qq

l+l-

W, Z, H

Atmospheric background

atm. : absorbed by the Earth

atm. : compare on/off source

angular regions

“down”

“up”


Data and Monte Carlo used

Data1997-1999: 5.0x109 events 536.6 days eff. livetime2001: 8.7x108 events 143.7 days eff. livetime

Monte Carloneutralino: 50 GeV < M < 5000 GeV[DARKSUSY] hard (W+W-) and soft (bb) ann. channel

90° < < 113° (Sun) ~ 180° (Earth)

atm. : Sun: 32 days Earth: 128 days[CORSIKA] 600 GeV < Ep < 1011 GeV 0° < p < 90°

atm. : Sun: 2.104 evts Earth: 2.108 evts [ NUSIM ] 10 GeV < E < 108 GeV 80° < < 180°


Rejection of signal & background

Earth 1997-1999 (paper in preparation)

Sun 2001 (submitted to Astrop. Phys.)


No excess of neutralino-induced neutrinos

signal region

signal region

Earth 1997-1999 (paper in preparation)

Sun 2001 (submitted to Astrop. Phys.)


Muon flux limits – Earth ’97-’99

Improvements (wrt. ’97)separate filter for each neutralino model

more statistics

Outlook2001-2003 data set

improved reconstructions

new trigger lowers Ethresh

PA

PE

R IN

P

RE

PA

RA

TIO

N


Muon flux limits - Sun 2001

1st AMANDA solar neutralino results200m diameter enables robust reconstruction of horizontal tracks

Outlook2000-2003 data setimproved reconstructions

new trigger lowers Ethresh

AMANDA results submitted for publication


Conclusion & outlook

AMANDA & IceCube:Amanda

provided very useful information (ice, drilling, detection strategy, bkgd, ...)

providing tighter and tighter constraints on models

IceCubeall flavour detection, ~30x more sensitive almost guaranteed discoveries

Is being deployed and takes data

WIMPs search:No statistically significant excess of neutralino-induced neutrinos from the center of the Earth or the Sun observed

Upper limits on the muon flux competitive with other indirect searches

Additional data are being analysed with improved techniques


Technically

Optical Module

Digital Optical Module

Trigger, Digitization, HV

Surface DOM

time res. <2ns400ns and 6.4µs range3 gainsnoise ~700Hz

time res. ~4-8 ns32 µs rangenoise: ~1kHz

Digitized Waveform

8” PMT

10” PMT+Main Board+flasher

Amanda IceCube

single p.e.


Plan...

Season planning:

Nov.: preparationDec.: constructionJan.: constructionFeb.: commissioning

Deploymentof string N

Drilling of hole N

0h 12h 24h 36h 48h 60h 72h 84h

Time

This austral summer : 8 to 12 strings deployed

By 2010 : 1km³ instrumented

Vrije Universiteit Brussel, Belgium

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