CW James ECAP University of Erlangen on behalf of the ANTARES collaboration Cosmic rays and neutrinos What produces this spectrum Standard model acceleration at relativistic astrophysical shocks ID: 429279
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Slide1
The ANTARES Underwater Neutrino Telescope
C.W. James,
ECAP, University of Erlangen,
on behalf of the ANTARES collaboration.Slide2
Cosmic rays and neutrinos
What produces this spectrum?
Standard model: acceleration at relativistic astrophysical shocks
R.
Shellard
, Braz. J. Phys 31 (2001) Slide3
Why
look for neutrinos?
Flux
unattenuated
over cosmological distances
Image courtesy of NRAO/AUI
Nature 432 (2004) 75
Image courtesy of NRAO/AUI
Travel in straight lines (unlike cosmic rays)
Signatures of
hadronic
processes in the high-energy universe
SNR
AGN jets and lobes
GRB
NASA/Swift/Stefan
ImmlerSlide4
Quick note: these are not Solar neutrinos!
Production via cosmic-ray (~proton) interactions with:
Much rarer than solar neutrinos – but more energetic (
GeV-PeV
: not MeV)νμ and ντ CC interactions possible
l
ow E proton
Hadronic
matter
(interstellar
gas)
Photon fields (CMB)Slide5
m
42°
interaction
Earth’s crust
(sea floor; Antarctic continent)
Cherenkov light
from
m
3D PMT
array
n
m
Main detection channel:
CC interactions
(
NC, and
e and
also
).Detection Principle
n
m
p
n
m
n
m
m
p,
a
5
Optically transparent material
(water; deep ice)Slide6
Let’s build it!Slide7
7
CPPM,
Marseille
DSM/IRFU/CEA,
Saclay
APC, Paris
LPC, Clermont-Ferrand
IPHC,
Strasbourg
Univ. de H.-A.,
Mulhouse
LAM,
Marseille
COM,
Marseille
GeoAzur
Villefranche
INSU-
Division
Technique
Univ./INFN
of Bari
Univ./INFN
of
Bologna
Univ./INFN
of Catania
LNS–Catania
Univ./INFN
of Pisa
Univ./INFN
of Rome
Univ./INFN
of
Genova
IFIC, Valencia
UPV, Valencia
UPC, Barcelona
NIKHEF,
Amsterdam
Utrecht
KVI
Groningen
NIOZ
Texel
ITEP,Moscow
Moscow
State
Univ
University
of
Erlangen
Bamberg
Observatory
Univ. of
Wurzeburg
ISS,
Bucarest
8
countries
31
institutes
~150
scientists
+
engineers
LPRM,
Oujda
The ANTARES CollaborationSlide8
ANTARES: Location
40km off the coast of ToulonSlide9
V. Bertin - CPPM - ARENA'08 @ Roma
The ANTARES detector
70 m
4
50 m
Junction
BoxInterlink cables
40 km to
shore
2500m
12
lines
25
storeys
/line
3 PMTs /
storey
885 10-inch
PMTs
10-20 Mton volume
Slide10
Sample events
Maximum-likelihood fit to recorded photon hit times
http://www.pi1.physik.uni-erlangen.de/
antares
/online-display/online-display.phpSlide11
ANTARES ‘visibility’
ANTARES at 43
o
NSensitive to the Southern skyIncludes the Galactic Centre
Mkn 501
RX J1713.7-39
GX339-4
SS433
CRAB
VELA
Galactic
Centre
Visible
Invisible
ANTARES: 43
o
N
Never visible
Always visible
Increasing sensitivitySlide12
n
m
ANTARES performance: angular resolution
~50% events reconstruct to better than 0.5
o
~99% reconstruct to better than 10oEnergy reconstruction is much harder (most is not ‘seen’)Slide13
Muon
and neutrino backgrounds
Remove atmospheric
muon background with quality cutsCR neutrino background irreducible
1%
misreconstructionfrom belowfrom above
p
n
m
m
p,
a
Muon
flux at 2500m depth
Look for an excess here!Slide14
Science with ANTARES
High-energy Neutrino Astrophysics
Galactic sources: SN & SNR, micro-quasars, CR in molecular clouds
Extra-galactic sources: AGN, GRB, GZK processesSearch for new physics:Dark matter annihilation, nuclearites, monopolesEarth sciences:
Oceanography, marine biology, seismology, environment monitoring…
GeV-100
GeV
GeV-TeV
TeV-PeV
PeV-EeV
>
EeV
Oscillations
DM
SNR,
μQSO
AGN
Exotics, GZK
Marine biology
GUT???Slide15
Results!Slide16
All-sky point-source search
Sky map in equatorial coordinates
:
2007-2010 data (813 days livetime)3058 candidates after cuts: expect 14% down-going muon contamination
Most significant cluster: 2.2σ
No strong evidence for a point-source excessSlide17
Search from suspected sources
51 pre-defined ‘suspect’ sources (mostly based on gamma-ray flux and visibility)
Top 11 sources: most significant first
WR20a & b: hot, massive stars
HESS, Astronomy & Astrophysics 467 (2007) 1075Slide18
Neutrinos from gamma-ray bursts
‘Fireball’ model for GRBs:
Explains long-duration bursts
Predicts neutrinos!
Search criteria:Direction (2o from source)Time (~1 minute)Upcoming events onlyResults from 2007 data (40 GRBs): no detectionSlide19
Neutrino Oscillations
Two-
flavour
mixing approximation:Measureable: ‘Unknown’: World data: 1st minimum at , (120 m max muon
range)Expectations for 863 days’ data:
Events seen with two lines
Events seen with one line
No oscillations
Best world dataSlide20
Oscillation analysis: results
After a Chi
2
minimisation to and two systematic variables:
1st measurement of its typeAccepted July 2nd by Physics Letters BPromising for next-generation larger detectors
DataNo oscillationsBest fitCombined single and multi-line data
ANTARESK2KMINOS
Super-K68% C.L.
90% C.L.Slide21
Search for Dark Matter Annihilation in the Sun
Muon
Flux Limits 90%CL (2007-2008)
21
PRELIMINARY
Angular distance from sun
Lack of excess: => model limits
(apologies: I do not have these plots here!)
A search for an excess from the galactic
centre
is ongoingSlide22
Search for magnetic monopoles
Relativistic monopoles emit VC radiation
8550 times brighter than a
muon
Look for extremely bright events!ANTARES search spaceRelativistic ‘intermediate mass’ (< 1014 GeV)
Search performed on data from 2008:
1 event
0.13 bkgd
1.5
σ
significanceSlide23
Multi-Messenger
astronomy
Alerts
Strategy:
Increase discovery potential (different probes)
Increase significance via coincidence
Ligo
/Virgo (
grav
. waves)
Dedicated analysis chain
GW trigger
GCN (GRB)
Global burst network
GRB burst alert
ANTARES trigger and coincident analysis
TAROT (optical)
Follow-up search for SN
10s repositioningSlide24
Summary
ANTARES underwater neutrino telescope:
Largest neutrino telescope in the Northern
HemisphereProven ability to detect neutrino-induced muonsGood performance in bread & butter science: neutrino astrophysicsSensitivity optimised for the galactic
centre regionDiverse physics program:Dark matterNeutrino oscillationsExotics (magnetic monopoles, nuclearites)Entering ‘mature’ phase:
First round of results published (~1 year’s data)Analyses on 3+ years of 12-line data in progressMore results on their way!Slide25
Extra Slides
(in case of tricky questions)Slide26
Background and diffuse flux sensitivity
High energies
favour
source spectraBackground from atmospheric neutrinos: Enu-3.7Sources: order Enu-2Look for a high-energy excess!
E2
F(E)90%= 5.3×10-8 GeV cm-2 s-1 sr-1 20 TeV<E<2.5 PeVEnergy estimation: the ‘R’ parameterLimits on an E-2 fluxSlide27
Standard data pipeline
‘hit’: send PMT data to shore when one or more photons are observed
Raw data rate: too high to record
Trigger: Record data to disk if it looks `interesting’.Standard trigger requirements:Large ( ) hits OR hits on
neighbouring PMTs (600 Hz)Clusters of >=5 hitsTrigger hits must be causally connectedMany other triggers (GRB alert, monitoring info, GC etc)
Threshold: 0.3
V
photon
PMT voltage
25 ns integration
Shore triggering and data acquisitionSlide28
Candidate List Search – 90%CL Flux Limits
28
Assumes E
-2
flux for a possible signalANTARES 2007-2010 813 daysANTARES has the most stringent limits for the Southern SkySlide29
Bioluminescence: large seasonal fluctuations
Bacteria
Vertebrates
Optical Background
Potassium 40 decay: constant background
Image courtesyWolfram Alpha
Spring 2006
Spring 2007Slide30
Trigger effective area
(preliminary plot: officially updated version will be out shortly)Slide31
Data reduction for point-source search
Cut on angular-error estimate, and on fit qualitySlide32
Resolution: use the Moon’s shadow
The Moon blocks CR: expect reduction in the upcoming-event rate
884 days’
livetime
2.7 sigma defecitAgrees with Monte Carlo expectationsSlide33
Sea currents
and
a
coustic positioning
Storey 1
Storey 8Storey 14Storey 20Storey 25Radial displacement
Measure every 2 min:
Distance line bases
to 5 storeys/line
and also storey
headings and tilts
Precision
~ few
cmsSlide34
2006 – 2008: Building phase of the Detector
Junction box 2001
Main cable 2002
Line
1, 2 2006Line 3, 4, 5
01 / 2007Line 6, 7, 8, 9, 10 12 / 2007Line 11, 12 05 / 2008
~70 mSlide35
Search for Neutrinos from Fermi Bubbles
For 100%
hadronic
models
:F ~1/2.5 F (Vissani)E2dF/dE=1.2*10-7 GeV cm-2s-1sr -1E cutoff
protons: 1PeV-10 PeV (Croker&Aharonian)
E cutoff neutrinos = 1/20 cutoff protons
Good
visibility
for ANTARES
Background
estimated
from
average
of three ‘OFF’ regions (time shifted in local coordinates)
galactic
coords
d
etector
coordsSlide36
Dark
Matter
Simulation
M
A
I
N
A
N
N
I
H
I
L
A
T
ION
C
H
A
N
NEL
S
36
M
WIMP
= 350
GeV
τ
leptons
regeneration
in the Sun
mUED
particular
case…Slide37
Dark matter – detector performance
ANTARES effective area to
muon
neutrinos incident on EarthMost neutrinos do not produce detectable muonsMost muons are very low in energySlide38
Magnetic Monopoles: data reduction
Magnetic monopoles…
Theoretical prediction (
quantisation of charge, guage theories…)Have not been observed (various limits exist)Have a magnetic charge g: will emit Vavilov-Cherenkov radiation
VC radiation: 8550 times brighter than that of a muon with similar velocityAcceleration in cosmic magnetic fieldsSlide39
Search for Dark Matter Annihilation in the Sun
Muon
Flux Limits 90%CL (2007-2008)
39
PRELIMINARY
Angular distance from sun
PRELIMINARY