Recent Developments in Neutrino Telescopy

Spyros Tzamarias

HEP2012: Recent Developments in High Energy Physics and Cosmology

615 t of C2Cl4

The Nobel Prize in Physics 2002

Masatoshi Koshiba Raymond Davis Jr.

 

Riccardo Giacconi

These discoveries of low (<100MeV) energy extraterrestrial neutrinos led us to various achievements on basic neutrino properties (oscillations) and stellar evolution.

They also offer important possibilities to progress, e.g., with geoneutrinosand solar (CNO) neutrinos, and even more with supernova neutrinos.

Furthermore, the obtained knowledge and the increased confidence motivate us to continue, widening the scope and field of our investigation.

The current experiments are monitoring a huge range of energies!

Log(

E/eV

)

νμ

μ-

W-

d

As proposed by Markov in the late 50s, the neutrino-induced μ's offer the practical way to probe high energy neutrinos, whilst using the whole earth as an absorber of atmospheric muons.

The size of such a detector is dictated by the muon’s range (due to EM interactions)

i.e. the detector size for an efficient TeV-muon detection should be of the order of a km

ln

Extraterrestrial High Energy Neutrino SourcesOr

What do we need these neutrinos for ?

•Cosmic-Hadron accelerators can produce VHE CR’s, γ-rays and neutrinos•Electron acceleration is the main source of the non-thermal EM radiation, up to high energies (up to TeV). Many such e-accelerators have been identified.•There is a connection between the (multi-TeV) γ and neutrino production•Where are these Cosmic-Hadron accelerators?

ρg−CR ≈1eV / cm3 ≈10−12erg / cm3

V ≈1067cm3 , tesc ≈107 y

P =ρg−CRV / tesc ≈1041erg / s

rSN ≈0.03y−1, ESN ≈1051erg, ε ≈10%

W. Baade and F. Zwicky, Remarks on super-novae and cosmic rays , Phys. Rev. 46 (1934) 76

ρE>1EeV ≈3⋅10−19erg / cm3

Production Rate: R=ρE>1EeV

TH

=9⋅1044 ergMpc3 y

, TH ≈1010 y

thiscanbesaturatedby :

R≈900GRBGpc3 y

⋅1051ergEM OUTPUT1 24 34 OR R≈

150AGNGpc3

⋅2⋅1044erg / sEM OUTPUT

1 244 34 4

Galactic Sources

ExtraGalactic Sources

Neutrinos (for all distances) and gammas point to the source of origin. However…

There many kinds of HE neutrino sources (perhaps as many as the Supersymmetric Scenaria)

ν

WIMP(neutralino)

SUN

earth

Indirect Searches for Dark Matter

ICECUBE KM3NeT

Full Sky Coverage

Why neutrinos from Galactic γ-ray (TeV) sources are important ?Observation of PeV (1015 eV) γ-rays will point to hadron accelerators revealing the CR sources. However, a) PeV γ-rays do not survive large distances and b) the γ-ray spectra of the observed galactic sources exhibit energy cut-off

Neutrino observation from RX J1713.7-3946 will prove unambiguously the hadronic production of γ-rays

RX J1713.7-3946

~ e−E /Ec withEc ≈10TeV( )

REMINDER: there are not very reliable phenomenological models to predict precise upper bounds for the extragalactic neutrino fluxes

A more efficient (larger effective area, better resolution) than ICECUBE detector is needed to discover galactic sources

NEMO

21

KM3NeTInternational consortium involving more than 300 scientists from 10 EU countriesOne objective: build the most sensitive high energy neutrino telescopeKM3NeT is one of the 44pan-european researchinfrastructures on the ESFRI EU roadmap

22

An artists impression of KM3NeT (≈ 1/3)

Primary Junction box Secondary Junction boxes

Detection Units

Electro-optical cable

signal hits

background hits pictorial representation of a ν charged current interaction inside the neutrino telescope

Pattern Recognition and Track Reconstruction

Eν<10 TeV

10TeV<Eν<100 TeV

100TeV<Eν<1 PeV

1PeV<Eν

Angle (ψ) between reconstructed muon track and parent neutrino (Degrees)

z

x y

(θm, φm)

ψ

(θtrue, φtrue)

2 22 2 2 2

1 1 1 1 1 12 cos2 22 2 2 2

0

( )2

x y x y

ws s s s

x y

P e e dws s

Can we estimate accurately the tracking errors?Median of Ψ (degrees) vs the cosine of the zenith angle

Energy Estimation

HOU Reconstruction & Simulation (HOURS): A complete simulation and reconstruction package for Very Large Volume underwater neutrino Telescopes, A. G. Tsirigotis et al., VLVNT2009

Reconstructed Energy (log of GeV)

0.5<cos(θ)<0.55

R.ADecl.

RX J1713.7-3946

Comparison of the Discovery Potentials

Number of events (N) – Angular profile (S) – Energy (E)

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 160.50

5.00

T180 NES

T180 NS

T180 N

T180(A)

years

Dis

cove

ry P

oten

tial i

n un

its o

f the

re

fere

nce

flux

RXJ1713

5-σ DISCOVERY POTENTIAL

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

T180 T150

T130 S130

S100

years

Dis

cove

ry P

oten

tial i

n un

its o

f the

re

fere

nce

flux

1,00

3 3.5 4 4.5 5 5.5 6 6.5 7 7.5 8 8.5 9 9.5 100.70

T180

Polynomial (T180)

T150

Polynomial (T150)

T130

Polynomial (T130)

S130

Polynomial (S130)

S100

Polynomial (S100)

FOM (years of observation time)5-σ DISCOVERY.

8.4y

7.6y

6.4y

6.0y

5.6y

1,00

KM3NeT with 608 strings at 100m (130m) apart will discover a neutrino source as the RXJ1713 after 5.6 (6) years of observation. The estimation error is less than 0.8y.

PRELIMINARY: An extra 30% improvement ( i.e a discovery after 4 y of observation) can be achieved by taking into account the known source direction. A further improvement is expected by developing a more efficient method to reject low energy atmospheric neutrinos., see A. Tsirigotis talk

KM3NeT-PP general meeting - Catania, february 22 2012

33

KM3NeT and EMSO

E. Migneco

Real Time Environmental Monitoring

Sinergy with the Earth and Sea Science Community

Toulon, Sicily and Hellenic: sites of common interest for KM3NeT

and EMSO

Geophisics (geohazard):Seismic phenomena, low frequency passive acoustics, magnetic field variations,...

Oceanography (water circulation, climate change): Current intensity and direction, Water temperature, Water salinity ,...

Biology (micro-biology, cetaceans,...):Passive acoustics, Biofouling, Bioluminescence, Water samples analysis,...

What after the Preparatory Phase?

• Need an organizational structure to manage the post-design and preparatory phase

• A Memorandum of Understanding is in preparation• Goals

– Complete the Physics Studies and the Optimization of the design– Validation of chosen technologies– Complete the final Technical Proposal– Central management– Definition of collaboration rules– Start of construction with engineering arrays in the potential

“host” sites