XI International Conference on Calorimetry in High Energy Physics

1
XI International Conference on Calorimetry in
High Energy Physics
Ultra High Energy Neutrino Astronomy
Antonio Capone University La Sapienza and
Istituto Nazionale di Fisica Nucleare Roma
-Italy
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Recent developments in Astroparticle physics

• Observation of TeV gamma sources
• Observation of GRB in a large bandwidth
  (BeppoSAX)
• Observation of UHECR (AGASA and Flys Eye)

• Ultra High Energy Cosmic Rays (UHECR)
  puzzle
• Which is the acceleration mechanism?
• Where are the sources ?

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Recent developments in Astroparticle physics
galactic origin
extragalactic contribution
unknown origin
1020 eV ? 17 Joules
AGASA Data (1999)
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Bottom Up Scenario Astrophysical Sources
Power source

• Gravitational
• Electromagnetic

Acceleration Fermi mechanism
Egt1020 eV

• Large cosmic objects
• Intense magnetic field
• High shockwave velocity

Hillas plot
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Known g sources the EGRET catalog
3rd EGRET catalogue
271 sources Total
P1234 230
AGN 85
Pulsars 5
G. Plane 52
Off G. Plane 87
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Active Galactic Nuclei

• AGN Blazars
• Markarian 421
• Markarian 501

Within the Blast Wave first order Fermi
Acceleration
UHE g
UHE n

• Blast Waves
• in the core
• in the jet G 10

UHE p
UHE g
Jet Blast Wave (L0.01 pc, B5 G)
Black Hole
Soft g
Accretion disk
NGC4261 Photo from HST
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Active Galactic Nuclei
The brightest continuous sources Luminosity1042
erg/sec

• e.m. models High Energy g production mechanism
• Electrons emit Synchrotron Radiation (low energy
  ?SR)
• High Energy ? from Inverse Compton scattering
  (e, ?SR)
• within the jet
• hadronic models g and n production
• protons emit synchrotron radiation
• (p,p) (p,g ) D resonance within the jet
  originates g and n

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Astrophysical Beam Dump
both gammas and neutrinos are produced in cosmic
accelerators if

• F(g) F (n) at the source
• the neutrino spectrum follows the primary CR
  spectrum

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Gamma Ray Bursts
Fireball Model Power Source Coalescence NS-NS or
NS-BH Acceleration of UHECR Blast Waves in an
Expanding Ultra-relativistic Fireball (G ?
300) Fermi Mechanism Sudden changes in optical
depth 10511053 ergs released in few ms
VELA - BATSE Beppo-Sax
VELA (1967) BATSE Beppo-Sax

GRB 990123
1 burst/day (4p/3sr)
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Neutrinos from Topological Defects and/or WIMPs

• Topological Defects or meta-stable particles
  originated in the early Universe may decay
  producing X particle
• Sequential decay of X particle produces UHE
  leptons and quarks
• UHECR are observed if
• mX 10241025 eV
• distance from Earth is lt 100 Mpc

Weak Interacting Massive Particles (WIMPs)
such as Neutralini c (supersymmetric dark
matter) are attracted, due to gravity, by the
Sun/Earth and the Galactic Center where they
annihilate c c ? leptons, heavy quarks ? n X
En 1/4 m c
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Super Novae detection
The first example of n astrophysics ! SN1987A
(in LMC 180,000 ly) IMB Kamiokande (?10 ne
detected) 1 event every 50 years

• Mainly low energy ne (30 MeV)
• 1053 erg released in few seconds

A large volume Cherenkov detector can see far
SN events as a simultaneous enhancement of PMTs
rate
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Different particles, different horizonts ...

• p e ? absorbed and/or deflected by matter and
  interstellar radiation
• ? interact weakly allow far Universe
  observation

protons Egt1019 eV (10 Mpc)
cosmic accelerator
neutrinos
gamma rays (0.01 - 1 Mpc)
Particles with energy gt 1017 eV
protons Elt1019 eV
1 parsec (pc) 3.26 light years
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The GZK cutoff

• g observed from extragalactic sources up to
  Eg10100 TeV
• p and g with E 1018 eV strongly attenuated in
  the Universe
• AGASA and Flys Eye events with E1020 eV have
  not, yet, identified a point like source
• For E1014eV only neutrinos, escaping the
  interactions with IM and CMBR, allow to detected
  point like sources in the far Universe

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Expected UHE neutrino fluxes
(Moscoso, 1999)
AGN Model Stecker
Extragalactic sources
AGN Models Protheroe, Mannheim
Top Down neutrinos
GRB (fireball model) good candidates but big
variability in flux calculations depending on GRB
distance (Halzen, 1999)
Atmospheric neutrinos
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Neutrino interactions
Weack CC interaction
n
lepton
Hadronic Shower
En lt 5TeV sDIS? E En gt 5TeV sDIS?log (E) En gt
PeV Earth is opaque
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Muon propagation
ionisation radiative processes nuclear
scattering Cherenkov
Strong effect for electrons
Lepton Enegy Loss
Muons have long tracks in water
4m / GeV
(Lohmann, 1985)
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UHE neutrino detection
Deep-sea water can offer the ideal solution to
detect faint UHE neutrino fluxes.
Seawater acts as Target for neutrino-muon
conversion Cherenkov radiator Shielding for the
atmospheric muons
The detector volume is a function of seawater
optical properties and of number of PMTs
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The km3 underwater Cherenkov detector
atmospheric muon
PMT strings
l400 m
Cherenkov light
neutrino
muon
Connection to the shore
depth 3500m
neutrino
Picture from ANTARES
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Deep sea site selection

• Proximity to the coast and to existing
  infrastructures
• feasibility of data and power transmission
  without signal amplifiers
• improvement in sea operation
• technological support
• Depth
• reduction of atmospheric muon flux
• Water optical transparency
• optimisation of detector performances (efficiency
  and angular resolution)
• Weak and stable deep sea currents
• reduce stresses on mechanical structures
• Low biological activity
• low optical background (bioluminescence)
• low biofouling and sedimentation on OM

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Light absorption in seawater
I(x) Io e-ax
La 1/a
Light absorption in seawater is less effective in
the blue-green region of the visible spectrum
glass cutoff350nm
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Pure water optical properties
Lb 1/b

• Blue light
• maximum transmission in water
• peak of PMT q.e.
• Cherenkov emission region

La 1/a
c
a
Lc 1/c
b
c(l) a(l) brayleigh(l)

• absorption (a)
• scattering (b)
• attenuation (c)

Smith Baker (1986)
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The lake-water approach BAIKAL NT-192

• 192 OM deployed
• Running since 1998
• Low depth ( 1400 m)
• upgoing atmospheric neutrino events reported
• Search for magnetic monopoles

In Baikal Lake, Siberia, Russia Lab s
222m Lscatt 3050m ltcos?gt 0,850,9
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Selected Baikal results
Effective area _at_ 1TeV 2000m2 Eff. volume
(showers) _at_ 10TeV 0,2 Mtons

• 192 Quasars PMT d37 cm
• Pairs of PMT in coincidence over 8 strings
• an heptagon frame with d40m
• 196 space points
• Calibration with N-laser
• Timing 1ns

One of the first neutrino events collected in
1996
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Selected Baikal results and perspectives
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The antartic ice approach AMANDA
7 US groups, 11 European groups 1 South American
group AMANDA II 677 OM in 19 strings (1996 -
2000)
1993-94 AMANDA-A - Labs200m - Lscatt0.3m
1995-1998 AMANDA-B10 302 PMT-10
strings 1999-2000 AMANDA-II 19 strings 200m
diameter
- Labs100m - Lscatt20m
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Building AMANDA
F. Halzen - 2003
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Selected AMANDA results
103 events/year upward going atmospheric
nm 109 events/year downward going atmospheric m
time
A real neutrino event in AMANDA

• Use upward going atmospheric nm as test beam
• Selection Criteria
• (Nhit lt 50 only)
• Zenith gt 110o
• High fit quality
• Uniform light deposition along track

MC
Data
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Selected AMANDA results point source and diffuse
n

• AMANDA-II
• Cuts optimized for each declination band
• Analysis developed with azimuth-scrambled data
  for blindness
• 25,000 m2 area above 10 TeV

Diffuse EHE neutrino flux limits
2000 data Contamination by cosmic ray muons
lt10 (above 110 degrees)

1. Stecker Salamon (AGN)
2. Protheroe (AGN)
3. Mannheim (AGN)
4. Protheroe Stanev (TD)
5. Engel, Seckel Stanev

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A seawater approach ANTARES
ANTARES aims at the construction of a Undersea
Cerenkov neutrino detector with an effective area
of 0.1 km2 at 2000 m depth near Toulon
Institute Michel Pacha (La Seyne sur Mer)
The shore station is at La Seyne sur Mer, around
40 km NW of the ANTARES site.
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A seawater approach ANTARES
High Energy
Medium Energy
Low Energy
Atmospheric n oscillations Observation of
first oscillation minimum
Neutralino search c c ? n X center of earth,
sun, galaxy GRB cannonballs
n from (extra-) galactic sources SN remnants,
AGN, GRB, ...
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A seawater approach ANTARES
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A seawater approach ANTARES
An 13th string dedicated to environmental
properties measurements will implement the
optical detector
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ANTARES prototypes deployed and recovered
2002-2003

• The Prototype Sector Line (PSL) is a 1/5 of a
  complete line.
• The Mini Instrumentation Line (MIL) contains
  devices for calibration and environmental
  parameter monitoring.
• The deployment (Dec02/Feb03) and connection
  (Mar03) of the lines were successful to the
  Junction Box (JB).

EOC
Prototype Sector Line
Mini Instrumentation Line
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ANTARES expected effective area

• For muons

• For neutrinos

• Detector response depends on thespectrum.
• For hard spectrum (E-2), most of the signal
  events are in the 10-100 TeV region.

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ANTARES expected angular and energy resolution

• Energy resolution is used to discriminate
  between atmospheric and cosmic neutrinos.
• At high energies, the energy resolution is a
  factor 2-3.

• Angular resolution
• For Elt10 TeV limited by ??-?
• At E10 TeV 0.4º
• At very high energies, it improves to 0.15 deg

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ANTARES expected sensitivities
Diffuse n fluxes
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NEMO
NEMO
NEutrino MediterraneanObservatory

• An RD program towards the construction of an
  underwater high energy neutrino detector
• Submarine technology development
• Site characterisation
• Software studies

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Deep Sea Mediterranean sites explored by the NEMO
collaboration

• Jonian Sea
• Capo Passero
• 35? 50 N, 16? 10 E (3350m)
• Tyrrhenian Sea
• Ustica
• 39? 05 N, 13? 20 E (3400m)
• Alicudi
• 39? 05 N, 14? 20 E (3400m)
• Ponza
• 40? 40 N, 12? 45 E (3500m)

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In situ Measurements of Inherent Optical
Properties
AC9 absorption(a), scattering (b) and
attenuation (cab) for 9 wavelengths 412, 440,
488, 510, 532, 555, 650, 676, 715 nm
absorbing Flow tube c measurement angular
acceptance 0.7
Ic(x)I0e-cx
Deep sea set-up AC9, CTD, battery pack, PC on
ship deck
Ia(x)I0e-ax
reflecting Flow tube a measurement
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Deep sea and pure water optical properties
Measurements are carried out in all the visible
wavelengths (412-715 nm)
Attenuation length 40m Absorption length
70m Transmission length 60m Lt1/ceff ceffabr
ayleighbmie(1-ltcosJgt) in deep ocean ltcosJgt
0.098
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Deep Sea Cerenkov Light attenuation study
Measurements carried out in Ponza site
raw data of attenuation coefficient at
412,488,510 nm
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Site Selection Light transmission in Capo
Passero
Seasonal characterisation of optical and
oceanographic parameters in Capo Passero KM4.
The column water shows at large depths
homogeneity and negligible variations
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Light Transmission Comparison between sites
ANTARES site vs Capo Passero KM4 site
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Capo Passero deep sea currents
Collected 3 years of deep-sea current data in
Capo Passero KM4 site. ---gt average current
intensity 3.1 cm/sec (rms 2.1) ---gt maximum
current intensity lt 16 cm/sec
RCM8 Mechanical current meter RCM11 Doppler
current meter
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Capo Passero sedimentation rate
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NEMO Deep Sea sites exploration activity

• The preliminary results show that the Capo
  Passero site has all the required caracteristics.
  In fact
• it is close to the coast ( 80 km)
• it is more than 3300 m deep
• the measured currents are low and regular (lt10
  cm/s)
• the light transmission length is 60 m
• the biological activity is low

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The proposed Km3 project towers à la NEMO
total height 750 m
number of arms 16
lowest arm (distance rom seabed) highest arm (distance from seabed) 150 m 750 m
distance between arms 40 m
arm length 20 m
OM per arm 4
OM per tower 64
Materials for construction Ti or fiberglass
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Deployment details
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The proposed Km3 project data transmission rate
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Nemo ed il progetto per il km3
Un cavo elettro-ottico 80km connetterà il lab.
a riva allapparato Cherenkov sottomarino
composto da 5000 PMT disposti su 64 torri
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NEMO Montecarlo results
NEMO simulations (Fast Montecarlo) PMT
diameter 15 time resolution 2.5
nsec detection threshold 0.25 p.e. q.e. 0.25
water transmission length 55m array height
300m trigger gt4 PMT hit Em flat in log10
102106 Jm flat in nadir angle 0p/2
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Biofoling measurements

• This multiparametric set-up is the first NEMO
  deep sea device built and can measure
• oceanographic parameters (water currents,
  temperature, salinity)
• degradation of the transparency of a glass sphere
  due to biological growth (biofouling) and
  sedimentation

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Sedimentation rate in Capo Passero and Toulon
Measured with a sediment trap moored at 3200 m
The sedimentation rate in the Ionian Sea is very
low due to the low biological activity and to the
absence of important rivers
Days since july 1st
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Deep sea currents
KM3
KM4
KM4 and KM3 Current Intensity _at_3300 m depth
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Test Site and the Laboratory at the Port of
Catania
2000 m
The realization, close to Catania, of a Test Site
connected to the shore via an electro-optical
cable is under way
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Existing approach to a km3 detector
Sea water vs.
Ice
Shorter absorption length (70 m) Longer
scattering length (gt60 m) 40K and biological
background Antares - NEMO - Nestor Initiated a
common effort the KM3NeT proposal to EU FP6
for a a km3 Detector in The Mediterranean Sea
Longer absorption length (? 200 m) Shorter
scattering length (few m) No optical
background Amanda IceCube Antartica
Baikal Lake water Absorption length 25 m No 40K
background relevant biological
activity Extending the present detector with 3
extra strings to achieve km3 for ne
complementary !!!
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Summary and outlook

• There are strong scientific motivations for the
  realisation of a high energy neutrino telescope
• Baikal and AMANDA have demonstrated the
  possibility to measure neutrino fluxes
• A detector in the northern hemisphere is needed
  and the Mediterranean Sea offers the best
  location
• Characteristics of the seawater telescope are
  complementary to the Antarctic ice approach
• A 0.1 km2 demonstrator will be built in Toulon by
  the ANTARES collaboration by 2003
• NESTOR will build a 1 tower demonstrator neutrino
  telescope
• NEMO will exploit the Test Site in Catania to
  test and develop technologies for the KM3
  neutrino telescope
• ICE-CUBE is starting to deploy strings in South
  Pole
• NEMO-ANTARES-NESTOR will collaborate on a common
  Design Study to define the candidate site for
  the installation and to define the future KM3
  neutrino telescope in the Mediterranean Sea

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CR and g Telescopes

• At Egt1020 eV UHE particle flux is about 1
  particle per km2 per century !
• 10 duty cicle

expected 102103 events per year
Large area detectors

• future
• Auger Observatory 6000 km2
• Telescope Array 5000 km2
• a step beyond
• OWL-AIRWATCH 3 million km2 sr (from satellite)

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Expected neutrino-induced muon fluxes

• atmospheric n
• vertical horizontal
• GRB
• vertical horizontal
• AGN blazars
• vertical horizontal
• Topological Defects
• vertical horizontal
• UHECR on CMBR
• vertical horizontal

Protheroe, 1998
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Acoustic and Radio Neutrino Detection
Deep Sea acoustic detection SADCO Pressure waves
are generated by e.m. showers. At EshowerPeV
propagation of waves with f10 kHz is 10-50km.
Good s/n reduction is needed.
in ice
Ice radiowaves detection RICE
Radio Cherenkov is emitted from e.m. showers
induced by ne interactions. Very promising for
UHE neutrinos.
j deg
j0 perpendicular to cascade axis
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Acoustic Detection
P Pa
Askaryan (1957) , Markov (1960), Learned (1979),

High energy shower ionization, heat
d
Pressure wave
t µs
K Eshower
P
C R d2
K expansion coefficient C heat capacity
?att in deep sea water _at_15-30 kHz few km !
R
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Radio Detection
electromagnetic shower a negative net charge
Qnet 0.25 Eshower
?e
e
n
X
The shower propagation (F10 cm in ice) induces
Cherenkov radiation for ?10 cm
A radio signal (0.2 1.2 GHz) Very fast signal
(few nsec) Very small attenuation ?att 1.5
km _at_ 0.5 GHz and 1km depth in antartic ice
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Galactic and Extragalactic Cosmic Rays
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Muon direction and shower energy detection
principle