Ultra High Energy Neutrinos in the Mediterranean: detecting n and n

Ultra
Ultra High
High Energy
Energy Neutrinos
Neutrinos in
in the
the
Mediterranean:
and nnmmwith
with
Mediterranean: detecting
detecting nntt and
33 telescope
aa km
km telescope
Gennaro Miele
Università degli studi di
Napoli “Federico II”
[email protected]
XII International Workshop on “Neutrino Telescopes”
Reference: JCAP02(2007)007
1
33
Why
to
detect
UHEn
at
a
Km
Why to detect UHEn at a Km
Neutrino
Neutrino Telescope?
Telescope?
At ultra high energy extragalactic n-flux dominates
Astrop. Phys. 20 (2004) 507
AMANDA Sensitivity
ICECUBE Sensitivity
G. Miele @ Neutrino Telescope 2007
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Two Main reasons for UHE
• The extragalactic contribution dominates:
extragalactic astronomy
• It is possible to measure simultaneously the
neutrino flux and the n-Nucleon cross
section, at energies and kinematical regions
never tested. Events nt and n m induced.
Final results:
The sensitivity increases for proper
km3-NT shape and orientation
G. Miele @ Neutrino Telescope 2007
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UHE
UHENeutrinos
Neutrinosare
areproduced
producedvia
via
••The
TheAcceleration
Acceleration mechanisms
mechanismsof
ofUHE
UHEcharged
chargedparticles
particles
••The
ThePropagation
Propagationin
inthe
thecosmo
cosmoof
ofUHE
UHEparticles
particles
• p + gb ö p + e- + e+
proton pair production
•N + gb ö N + n p
photo-production of single or
multiple pions
•n ö p +
e-
__
+ ne
neutron decay
Due to neutrino oscillation and UHECR we expect almost the same
UHE fluxes for ne , nm ,nt. But the fluxes are still unknown!
G. Miele @ Neutrino Telescope 2007
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The nt chances: two kinds of tracks
Earth-skimming nt a real chance
t tracks in water (air)
Fiducial Volume
t tracks in rock
t interaction range
larger or similar to the
decay length
•K.S.Capelle,
Capelle,J.W.
J.W.Cronin,
Cronin,G.G.Parente
Parenteand
andE.E.Zas,
Zas,
•K.S.
1998.
1998.
•F.Halzen
Halzenand
andD.D.Saltzberg,
Saltzberg,1998.
1998.
•F.
•F. Becattini and S. Bottai, 2001
•F. Becattini and S. Bottai, 2001
•Beacom,Crotty,
Crotty,Kolb,
Kolb,2001
2001
•Beacom,
•D. Fargion, 1999, 2002, 2005
•D. Fargion, 1999, 2002, 2005
•X.Bertou,
Bertou,P.P.Billoir,
Billoir,O.O.Deligny,
Deligny,C.C.Lachaud,
Lachaud,A.A.
•X.
Letessier-Selvon.,
2002
Letessier-Selvon., 2002
•J.L. Feng, P. Fisher, F. Wilczek and T.M. Yu, 2002
•J.L. Feng, P. Fisher, F. Wilczek and T.M. Yu, 2002
•D.Fargion,
Fargion,P.G.
P.G.De
DeSanctis
SanctisLucentini
Lucentiniand
andM.
M.De
De
•D.
Santis,
2004
Santis, 2004
•C.Aramo,
Aramo,A.A.Insolia,
Insolia,A.A.Leonardi,
Leonardi,G.G.Miele,
Miele,L.L.
•C.
Perrone,
O
Pisanti,
D.V.
Semikoz,
2005
Perrone, O Pisanti, D.V. Semikoz, 2005
•Z.Cao,
Cao,M.A.
M.A.Huang,
Huang,P.P.Sokolsky
Sokolskyand
andY.Y.Hu,
Hu,2005
2005
•Z.
G. Miele @ Neutrino Telescope 2007
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•M.M.Guzzo
Guzzoand
andC.A.
C.A.Moura,
Moura,2005
2005
•M.M.
•G.
Miele,
S.
Pastor
and
O.
Pisanti,
2006
•G. Miele, S. Pastor and O. Pisanti, 2006
EeV neutrinos have
interaction lenght ~ 500 Km
water equivalent in rock
Let us consider a Km3 in all the three sites proposed
in the Mediterranean
• Just a cube as fiducial volume
• No experimental details (Simplicity ansatz: each
charged leptons crossing the fiducial volume is detected)
• Underwater surface profile
We generate possible neutrino tracks which account
for the characteristics of Earth surface profile.
G. Miele @ Neutrino Telescope 2007
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3
The
The rate
rate of
of tt events
events in
in 11 Km
Km3
r
dN τ
dΦν ( Eν )
(
)
(
= D ∑ ∫ dΩ a ∫ dS a ∫ dEν
dE
ε
(
E
)
cos
θ
k
E
,
E
;
r
τ
τ
a
a
ν
τ a , Ωa )
∫
dt
dEν dΩ a
a
a = W, E, S, N, U, D
Same calculation for Auger FD
in PLB634:137-142,2006
Fiducial volume,
no experiment
characteristics, just
able to recognize a t
G. Miele @ Neutrino Telescope 2007
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For
Fornnttcrossing
crossingthe
therock
rock(Earth-skimming)
(Earth-skimming)
or
orwater.
water.
r
r
r
r
w
k a (Eν , Eτ ; ra , Ω a ) = k a (Eν , Eτ ; ra , Ω a ) + k a (Eν , Eτ ; ra , Ω a )
is the probability that an incoming neutrino crossing the
Earth (rock “r” events) with energy En and direction Wa,
produces a lepton emerging with energy Et , which enters
the fiducial volume through the lateral surface dSa at the
position ra. Similar definition for (water “w” events)
G. Miele @ Neutrino Telescope 2007
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r
k (Eν , Eτ ; ra , Ω a )
r
a
Takes three contributions, the main one is:
r
r
k a (Eν , Eτ ; ra , Ω a ) =
z max
∫
0
f Eν
dz
'
dE
∫ τ P1 P2 P3 P4 + ....
0
This process occurs if
1. the nt survives for some distance z in the Earth ( P1 )
2. nt ô t in z, z+d z ( P2 )
3. the t comes out from the Earth before decaying ( P3 )
4. the t is able to reach the fiducial volume ( P4 )
G. Miele @ Neutrino Telescope 2007
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Et

z 
P1 = Exp − ν

 λCC (Eν ) 
λνCC (Eν ) =
P2 =
E’t
1
σ νCC (Eν ) ρ s N A
z
nt
dz
λνCC (Eν )

 1
mτ
1
 ' −
P3 = Exp  −
 cτ τ βτ ρ s  Eτ f Eν
t
(

− βτ ρ s (z smax − z )
'
  δ Eτ − f Eν e

(

 1
mτ
1 
' − βτ ρ a z amax

P4 = Exp  −
− '   δ Eτ − Eτ e
 cτ τ βτ ρ a  Eτ Eτ  
)
)
zamax and zsmax are the total lengths in water and rock for a given
track. It depends on the real surface profile.
G. Miele @ Neutrino Telescope 2007
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ETOPO2
U.S. Department of
Commerce, National Oceanic
and Atmospheric
Administration, National
Geophysical Data Center,
2001. 2-minute Gridded
Global Relief Data (ETOPO2)
The horizontal resolution
is 2-minutes of latitude
and longitude (1 minute of
latitude = 1.853 km at
the Equator). The vertical
resolution is 1 meter.
G. Miele @ Neutrino Telescope 2007
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Satellite Radar Bathymetry: The
surface of the ocean bulges outward and inward mimicking
the topography of the ocean floor. The bumps, too small to be seen, can be measured by a radar
altimeter aboard a satellite. Over the past year, data collected by the European Space Agency ERS1 altimeter along with recently declassified data from the US Navy Geosat altimeter have provided
detailed measurements of sea surface height over the oceans. These data provide the first view of
the ocean floor structures in many remote areas of the Earth.
G. Miele @ Neutrino Telescope 2007
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NESTOR Site
Nestor Site
Pylos
• Site Location
36°21’ N, 21°21’ E
• Average Deep
~4000 m
(4166 in our
simulation)
G. Miele @ Neutrino Telescope 2007
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Antares Site
Toulon
Antares Site
• Site Location
42°30’ N, 07°00’ E
• Average Deep
~2600 m
(2685 m in our
simulation)
G. Miele @ Neutrino Telescope 2007
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NEMO Site
Etna
Nemo Site
• Site Location
36°21’ N, 16°10’ E
• Average Deep
~3500 m
(3424 in our
simulation)
G. Miele @ Neutrino Telescope 2007
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W
N
Nemo
W
Apertures
Aperturesfor
fortt
tracks
trackscrossing
crossing
the
therock
rockin
inNemo
Nemo
E
S
Matter
MatterEffect!
Effect!
S
D
N
E
U
G. Miele @ Neutrino Telescope 2007
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Apertures
Aperturesfor
fortt
tracks
trackscrossing
crossing
only
onlywater
waterin
in
Nemo
Nemo
G. Miele @ Neutrino Telescope 2007
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Comparison of Apertures
Auger FD
Nemo water
Nemo rock
G. Miele @ Neutrino Telescope 2007
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G. Miele @ Neutrino Telescope 2007
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Perfoming the exercise for some neutrino fluxes
Cosmogenic neutrino flux
per flavour
Kalashev et al. 01, 02, Semikoz & Sigl, 03
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~10-20% of difference
among the three sites
G. Miele @ Neutrino Telescope 2007
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# of yearly t events crossing the rock and the water
for a WB flux at Nemo. The same for other sites.
Even
Evenaafactor
factor10
10
for
formore
more
copious
copious fluxes!
fluxes!
Surface
D
U
S
N
W
E
Total
Nemo-r
0.006
0.000
0.026
0.023
0.034
0.019
0.11
Nemo-w
0.000
0.213
0.177
0.182
0.169
0.188
0.93
Mainly a shadowing effect!
G. Miele @ Neutrino Telescope 2007
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Rock/water events is a good estimator of n-Nucleon cross section
Unless t does not decay in the NT it cannot easily disentangled
from m
G. Miele @ Neutrino Telescope 2007
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Work in Progress!
The real observable is the energy lost (DE) in the detector summing
muons and tau’s contribution. An appropriate binning in arrival direction
and energy deposited provides a way to disentangle neutrino flux from
neutrino-Nucleon cross section,
DE = 105 - 108 GeV
DE > 108 GeV
snN(Standard), f(GZK_WB)
3 snN(Standard), f(GZK_WB)
snN(Standard), f(GZK_H)
G. Miele @ Neutrino Telescope 2007
00-600
600-850
850-1800
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00-600 600-850 850-1800
Distribution in arrival direction/energy loss rate for nt & nm
G. Miele @ Neutrino Telescope 2007
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Dependence of the event rate upon the shape of the NT detector
for a fixed total volume of 1 km3.
CUBE
PARALLELEPIPED
Consider the E and W surfaces enlarged by a factor 3 in the
horizontal dimension, and the N and S surfaces being reduced by the
same factor, keeping the height of towers still 1 km.
rock events per year is enhanced by almost a factor 2, from 0.11
to 0.18 for the GZK-WB flux (enhancement enlarges for more
energetic neutrino fluxes). Moreover, the expected rate of water
events increases by a factor of the order of 50%, from 0.93 up to
1.40 per year.
G. Miele @ Neutrino Telescope 2007
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Conclusions
• UHE neutrino detection allows for extragalactic n-astronomy, and
makes possible the simultaneous measurements of the nN cross,
section at energy ranges never explored before (New Physics?), and
the value of neutrino flux. This depends on the different behavior of
the rock and water events on these quantities (work in progress).
• To performe the measurement one has to enlarge the number of rock
and water events already too small. This can be done by working on
the shape of NT, in correlation with the position of the coast line
(shadowing effect).
G. Miele @ Neutrino Telescope 2007
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