First-generation neutrino telescopes. neutrino muon or tau Cerenkov light cone Detector interaction...
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Transcript of First-generation neutrino telescopes. neutrino muon or tau Cerenkov light cone Detector interaction...
first-generation first-generation neutrino telescopesneutrino telescopes
neutrino
muon or tau Cerenkov
light cone
Detector interaction
•Infrequently, a cosmic neutrino is captured in the ice, i.e. the neutrino interacts with an ice nucleus
•The muon radiates blue light in its wake
•In the crash a muon (or electron, or tau) is produced
•Optical sensors capture (and map) the light
size perspectivesize perspective
50 m
Amundsen-Scott Station South Pole
Optical module
1996-2000
AMANDA IIAMANDA II
South PoleSouth Pole
AMANDA– 1 mile deepAMANDA– 1 mile deep
Building Building AMANDAAMANDABuilding Building AMANDAAMANDADrilling Holes with Drilling Holes with
Hot WaterHot Water
The Optical ModuleThe Optical Module
Christchurch, New ZealandChristchurch, New ZealandInternational Antarctic CenterInternational Antarctic Center
Logistics simple!Logistics simple!
thethe domedome
the new stationthe new station
Building AMANDABuilding AMANDA
AMANDA IIAMANDA II
• up-going muonup-going muon• 61 modules hit61 modules hit
ttiimmee
size ~size ~ number of photonsnumber of photons
> 4 neutrinos/day> 4 neutrinos/day on-lineon-line
AMANDA AMANDA Event Event
Signatures:Signatures:MuonsMuons
AMANDA AMANDA Event Event
Signatures:Signatures:MuonsMuons
+ N + N + + XX
CC muon neutrinoCC muon neutrinoInteractionInteraction tracktrack
two eventstwo events
200 TeV e
event reconstructionevent reconstruction
• Maximum Likelihood Maximum Likelihood methodmethod
• Take into account time Take into account time profiles of expected profiles of expected photon flight timesphoton flight times
• Bayesian approach - Bayesian approach - use prior knowledge use prior knowledge of expected of expected backgrounds and backgrounds and signalssignals
Quality parameters: Quality parameters: Example 1: The track Example 1: The track
lengthlength• Short track
length = more likely to be background
Ldir m
Data
Atmospheric MC
0
5
10
15
20
25
30
05 0 100 150 200 250 300 350 400
Quality parameters: Quality parameters: Example 2: The Example 2: The
smoothnesssmoothness• The smoothness is a
measure of how regular the photon density is distributed along the track.
• A well reconstructed muon track is more likely to have a high smoothness.
| SPhit |
Data
Atmospheric MC
0
5
10
15
20
25
30
35
40
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
High Low
Quality parameters: Quality parameters: Example 3: The Example 3: The
angular difference angular difference between 2 fitsbetween 2 fits
• A well reconstructed event has better agreement between a simple fit and a full likelihood reconstruction.
like - LF
Data
Atmosph. MC
0
5
10
15
20
25
30
35
40
-60 -40 -20 02 04 06 08 0 100
Quality ParametersQuality ParametersQuality ParametersQuality Parameters• LikelihoodLikelihood• Zenith angle Zenith angle
mismatch between mismatch between two types of fits.two types of fits.
• Sphericity of Hits Sphericity of Hits (Brem?)(Brem?)
• Track Length (is an Track Length (is an energy cut, too)energy cut, too)
• Smoothness of hits Smoothness of hits along the trackalong the track
• Number of Number of unscattered photonsunscattered photons
• Combine 6 to a Combine 6 to a ssingle event ingle event quality quality parameter.parameter.
• Only 3 for Only 3 for completed completed detector!detector!
quality cutquality cut
Data
Atmospheric MC
Downgoing m MC
Quality Cut
10-1
1
10
10 2
10 3
10 4
0 2.5 5 7.5 10 12.5 15 17.5 20 22.5 25
Atmospheric muons and Atmospheric muons and neutrinosneutrinos
• Atm. Neutrinos (): 60/day• Atm. Muons: 8.6*106/day
Lifetime: 135 days
Observed Data
Pred. Neutrinos
Triggered1,200,000,00
04574
Reconstructed upgoing
5000 571
Pass Cuts (Q ≥ 7) 204 273
Atmospheric Neutrinos, 97 data
vertically up horizontally AMANDA sensitivity understood down to normalization factor of ~ 40% (modeling of ice ...)
~ 300 events
Understanding Ice and Understanding Ice and Calibrating AMANDACalibrating AMANDA• In situ light sourcesIn situ light sources
– Ice propertiesIce properties– Relative PMT timing, gainRelative PMT timing, gain– Response to electromagnetic showersResponse to electromagnetic showers– crosstalkcrosstalk
• Downgoing cosmic-ray muonsDowngoing cosmic-ray muons– Relative PMT timing, gainRelative PMT timing, gain
• AMANDA-SPASE coincidencesAMANDA-SPASE coincidences– DirectionalityDirectionality– Ice propertiesIce properties
• Atmospheric neutrinosAtmospheric neutrinos– Full detector responseFull detector response
Amanda: time delay due to Amanda: time delay due to scatteringscattering
Amanda: time delay due to Amanda: time delay due to scatteringscattering
3 50 200 400 700
6 m
17 m
d=32 m
delay, nsec
d
muon
Ice PropertiesIce PropertiesIce PropertiesIce Properties
• Most Most challenging challenging initial initial problems now problems now understood understood using using in situin situ lasers and lasers and LEDsLEDs– Disappearance Disappearance
of bubblesof bubbles– Mapping of Mapping of
dust layersdust layers
scatter scatter :: 6 m - 52 m6 m - 52 m
abs abs : 9 m - 240 m: 9 m - 240 m
AMANDA Is Working Well: 4 nus AMANDA Is Working Well: 4 nus per day!per day!
• Sensitivity to up-going muons demonstrated with CC atm. nm interactions:
• Sensitivity to cascades demonstrated with in-situ sources (see figs.) & down-going muon brems.
In-situ light source Simulated light source
• AMANDA also works well with AMANDA also works well with SPASE:SPASE: • Calibrate AMANDA angular responseCalibrate AMANDA angular response• Do cosmic ray composition studies.Do cosmic ray composition studies.
Horizontal Up-going
MCData
290 atm. candidates(2000 data)
Zenith
Detector capabilitiesDetector capabilities
muons:directional error: 2.0 - 2.5°energy resolution:¶ 0.3 – 0.4coverage: 2
primary cosmic rays: (+ SPASE)energy resolution:¶ 0.07 – 0.10
„cascades“: (e±, , neutral current)zenith error: 30 - 40° energy resolution:¶ 0.1 – 0.2coverage: 4
effective area (schematic):
E
3 cm2
-interaction in earth, cuts
2 -5m2
100 GeV 100 TeV 100 PeV ¶[log10(E/TeV)]
AMANDA-IIAMANDA-IIAntarctic Muon And Neutrino Detector Antarctic Muon And Neutrino Detector
ArrayArray•Construction began Construction began in 1995 (4 strings)in 1995 (4 strings)•AMANDA-II AMANDA-II completed in 2000 completed in 2000 (19 strings total)(19 strings total)•677 optical 677 optical modulesmodules•200 m across200 m across•~500 m tall (most ~500 m tall (most densely densely instrumented instrumented volume)volume)
The AMANDA detectorThe AMANDA detector
• Construction began in Construction began in 1995 (4 strings)1995 (4 strings)
• AMANDA-II completed in AMANDA-II completed in 2000 (19 strings total)2000 (19 strings total)
• 677 optical modules677 optical modules• 200 m across200 m across• ~500 m tall (most densely ~500 m tall (most densely
instrumented volume)instrumented volume)
Slant Depth
17
30
m
8650m
1 2 3 45
67
8
Slant Depth BinningSlant Depth Binning zenith angle cos zenith angle cos θθ
Required background Required background rejectionrejection
SignatureSignature Neutrino signal Neutrino signal //
cosmic muon cosmic muon bkgbkg
Diffuse fluxDiffuse flux ~10~10-8-8
Point sourcePoint source >>1010-6-6
Gamma ray Gamma ray burstburst
>>1010-4-4
Atmospheric muons in Atmospheric muons in AMANDA-IIAMANDA-II
PRELIMINARY threshold energy ~ 40 GeV (zenith averaged)
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
Down-going Muon Down-going Muon FluxFlux
zenith zenith angleangle
depthdepth
Atmospheric Atmospheric ’s as Test Beam’s as Test Beam
Neutrino energy in Neutrino energy in GeVGeV
Atmospheric n's in Atmospheric n's in AMANDA-IIAMANDA-II
neural network energy reconstruction regularized unfolding
measured atmospheric neutrino spectrum
1 sigma energy error
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 usedIn future, spectrum will be usedto study excess due to cosmic to study excess due to cosmic ‘s‘s
PRELIMINARY
Cosmic Ray flux measurement
empirical separation of ice and OM sensitivity effects
PRELIMINARY
In some cases ice and OM-sensitivity effect can be circumvented ...
(E)=0E-
Compatible and competitive () with direct measurements
for QGSJET generator:
(H) = 2.70 ± 0.02 0 (H) = 0.106(7) m-2s-1sr-1TeV-1
talk HE2.1-13
South Pole
Dark sector
AMANDA
IceCube
Dome
Skiway
South Pole Air Shower Experiment (SPASE)
AMANDA-II: 200 x 500 cylinder + 3 1km strings, running since 2000
cosmic ray composition studies SPASE-2 (electronic component) - AMANDA B10 (muonic component)
AMANDA II
- unique combination!
talk HE 1.1-25
robust evidence for composition change around knee ...
AM
AN
DA
(co
rrel
ate
to #
muo
ns)
SPASE-2 (correlated to #electrons)
iron
proton
log(E/G
eV)
publication in preparation
Composition change around „knee“
1998 data
1015 eV 1016 eV
talk HE 1.1-25
A=30
A=6
confirms trend seen byother experiments ...
blue band: detector and model uncertaintiesred band: uncertainty due to low
energy normalization
1 km
2 km
SPASE air shower arraySPASE air shower array
Cosmic ray composition
preliminary
RelativistiRelativistic c
Magnetic Magnetic MonopoleMonopole
ss10-16
10-15
10-14
10-18
10-17
= v/c= v/c
1.000.750.50
up
per
lim
it (
cmu
pp
er li
mit
(cm
-2-2 s s
-1-1 s
r s
r-1-1))
C - light output C - light output nn22·(g/e)·(g/e)22
n = 1.33n = 1.33
(g/e) = (g/e) = 137137/ / 22
8300
KGF
Soudan
MACRO
Orito
Baikal
Amanda
IceCube
electrons
Excess of cosmic neutrinos?
Electron + tau (2000 data)
„AGN“ with 10-5 E-2
GeV-1 cm-2 s-1 sr-1
.. for now use number of hit channels as energy variable ...
muon neutrinos (1997 B10-data)
cuts determined by MC – blind analyses !
Excess of cosmic neutrinos? Not yet...
cascades (2000 data)
„AGN“ with 10-5 E-2
GeV-1 cm-2 s-1 sr-1
.. for now use number of hit channels as energy variable ...
muon neutrinos (1997 B10-data)
cuts determined by MC – blind analyses !
2.5 ·106 – 5.6 ·108 GeV:
E2 (E) < 7.2 10-7
GeV-1 cm-2 s-1 sr-1
3·103 – 106 GeV:
E2 (E) < 8 10-7
GeV-1 cm-2 s-1 sr-1
Expected sensitivity 2000 data:~ 3 10-7 GeV-1 cm-2 s-1 sr-1
AMANDA II (with 3 years data):~ 10 X higher Sensitivity
Diffuse flux muon neutrinos
Note that limits depend on assumed energy spectrum ...
prel.
diffuse limit cascadesdiffuse limit cascades
Effective volume
80 TeV – 7 PeV For E2(E) =10-6 GeV cm-2s-1sr-1
flux would expect:
9.3 e , 6.2 , 8.0 events
2 candidate events total observed
E2all (E) < 9·10 - 7 GeV cm-2s-1sr-1
90% CL limit, assuming e:: =1:1:1 :
PRELIMINARY
flux results summary (all flux results summary (all flavors)flavors)
assuming e:: =1:1:1 ratio:
2000 analysis will yield comparable result ...
special analysis for resonant
production (6.3 PeV)
multiplicative factor 3 applied for single e , channels …
eWe ee
...can combine analyses!
theoretical bounds and future
atmospheric
W&B W&B
MPRMPR
DUMAND test string
FREJUS
NT-200
MACRO
NT-200+
AMANDA-II 5 years
IceCube
AMANDA-97
AMANDA-00 100 days
opaque for neutrons
Mannheim, Protheroe and Rachen (2000) – Waxman, Bahcall (1999) derived from known limits on extragalactic protons + -ray flux
neutrons can escape
Excess of cosmic neutrinos?
Electron + tau (2000 data)
„AGN“ with 10-5 E-2
GeV-1 cm-2 s-1 sr-1
.. for now use number of hit channels as energy variable ...
muon neutrinos (1997 B10-data)
cuts determined by MC – blind analyses !
Ultra High Energy Neutrinos in AMANDAUltra High Energy Neutrinos in AMANDA
• Energy > 10 PeVEnergy > 10 PeV
• All skyAll sky
• Large neutrino cross sectionsLarge neutrino cross sections
•Large muon range (> 10 km)Large muon range (> 10 km)
Competitive with radio, acoustic and Competitive with radio, acoustic and air shower experimentsair shower experiments
diffuse EHE neutrino diffuse EHE neutrino flux limitsflux limits
a) Stecker & Salamon (AGN)
b) Protheroe (AGN)c) Mannheim (AGN)d) Protheroe & Stanev
(TD)e) Engel, Seckel &
Stanev
Ranges are central 80%
AMANDAAMANDASensitivity (00-03)Sensitivity (00-03)
sky subdivided into 300 bins (~7°x7°)
below horizon:mostly fake events
above horizon: mostly atmospheric ‘s 697 events observed above horizon 3% non-neutrino background for > 5° cuts optimized in each declination band
PRELIMINARY
point source search in AMANDA
Search for excess events in sky bins for up-going tracks
talk HE 2.3-5
no clustering observed - no evidence for extraterrestrial neutrinos ...
Sources declination 1997 ¶ 2000
SS433 5.0o - 0.7
M87 12.4o 17.0 1.0
Crab 22.0o 4.2 2.4
Mkn 421 38.2o 11.2 3.5
Mkn 501 39.8o 9.5 1.8
Cyg. X-3 41.0o 4.9 3.5
Cas. A 58.8o 9.8 1.2
selected point source flux limits
sensitivity flat above horizon - 4 times better than B10 ¶!
declination averaged sensitivity:
lim 0.23•10-7 cm-2s-1 @90%
PRELIMINARY
¶ published Ap. J, 582 (2003)
upper limits @ 90% CL in units of 10-8cm-2s-1
-90 0-45 9045
10-15
10-14
mu o
n s/c
m2 s
1
10-17
10-16
published data
1 km3 detector, 3 years1 km1 km33
expected sourcesensitivity
MACRO 8 years
N
AMANDA137 days
declination (degrees)
S
AMANDA+16 (2007)
GX339-4Antares
(2007+)
preliminary 2000 dataSS-433
Mark. 501
Crab
GRB GRB search in AMANDA search in AMANDASearch for candiates correlated with GRBs - background established from data
317 BATSE triggers (1997—2000) effective -area 50000 m2
low background due to space- time coincidence
No excess observed! assuming WB spectrum 4 x 10-8GeV/s/cm2/sr
analysis continues with non-triggered BATSE and IPN3 data …
<20°
PRELIMINARY
talk OG 2.4-7
• 90% upper limits calculated
using background
levels predicted from data
• “neutrino =gamma” sensitivity
• 0.04 km0.04 km22 area area above 10 TeVabove 10 TeV
3.12.5Cygnus X-3
0.8SS 433
1.00.7Cas-A
2.12.1Crab
1.51.3Markarian 501
3.02.6Markarian 421
(10-8 GeVcm-2 s-1)muon (10-15 cm-2 s-1)Source\90% limit
Point Sources Amanda II (2000)
0.6
AMANDA II 2000AMANDA II 2000
Declination RA(hours)Declination RA(hours) 6464 21 21 40 2140 21 20 920 9
-rays from -rays from 00 decay? decay?
EE NN (E (E) = ) = E E NN (E (E))
1 < 1 < < < 88transparent transparent sourcesource00 = = ++ = = -
acceleratoracceleratorbeam dumpbeam dump(hidden source)(hidden source)
flux predictedflux predicted Observed Observed -ray flux-ray flux
20 km20 km-2-2 yr yr-1-1 Crab sn remnantCrab sn remnant
35 km35 km-2-2 in 97 in 97 Markarian 501Markarian 501(9 for p(9 for p))
~