Ultra - High Energy Neutrino Astronomy

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Ultra - High Energy Neutrino Astronomy

• Dmitry
• Semikoz
• UCLA, Los Angeles
• in collaboration with
• F.Aharonian, A.Dighe, O.Kalashev, M.Kachelriess,
  V.Kuzmin, A.Neronov, G.Raffelt, G.Sigl ,
  M.Tortola and R.Tomas

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Overview

• Introduction high energy neutrinos
• Experimental detection of high energy neutrinos
• Under/ground/water/ice
• Horizontal air showers
• Radio detection
• Acoustic signals from neutrinos
• Neutrinos from UHECR protons
• Neutrinos from AGN

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• Most probable neutrino sources
• Neutrinos from Galactic SN
• Neutrinos in exotic UHECR models
• Conclusion

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INTRODUCTION
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Extragalactic neutrino flux?
Georg Raffelt, Max-Planck-Institut für Physik
(München)
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Neutrino Signal from SN 1987A
Kamiokande (Japan) Water Cherenkov detector
Clock uncertainty ?1 min
Irvine-Michigan-Brookhaven (USA) Water
Cherenkov detector Clock uncertainty ?50 ms
Baksan Scintillator Telescope (Soviet Union)
Clock uncertainty 2/-54 s
Within clock uncertainties, signals are
contemporaneous
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Atmospheric n's in AMANDA-II
? neural network energy reconstruction ?
regularized unfolding
PRELIMINARY
1 TeV
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Why UHE neutrinos can exist?

• Protons are attractive candidates to be
  accelerated in astrophysical objects up to
  highest energies E1020 eV.
• Neutrinos can be produced by protons in PP -gt
  pions or Pg-gt pions reactions inside of
  astrophysical objects or in intergalactic space.
• Neutrinos can be produced directly in decays of
  heavy particles. Same particles can be
  responsible for UHECR events above GZK cutoff.

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Pion production
n
p
Conclusion proton, photon and neutrino fluxes
are connected in well-defined way. If we know one
of them we can predict other ones
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High energy neutrino experiments
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Neutrino nucleon cross section

• Proton density
• np 1024/cm3
• Distance R104km
• Cross section
• snN1/(Rnp)10-33cm2
• This happens at energy E1015 eV.

E0.4
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Experimental detection of Elt1017eV neutrinos

• Neutrinos coming from above are secondary from
  cosmic rays
• Neutrino coming from below are mixture of
  atmospheric neutrinos and HE neutrinos from space
• Earth is not transparent for neutrinos Egt1015eV
• Experiments MACRO, Baikal, AMANDA

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Experimental detection of UHE (Egt1017eV)
neutrinos

• Neutrinos are not primary UHECR
• Horizontal or up-going air showers easy way to
  detect neutrinos
• Experiments Flys Eye, AGASA, HiRes

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Radio detection
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Experiments GLUE, RICE, FORTE
Threshold gt 1016 eV
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Acoustic detection
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Particle cascade ? ionization
? heat
? pressure wave
Maximum of emission at 20 kHz
Attenuation length of sea water at 15-30 kHz a
few km (light a few tens of meters) ? given a
large initial signal, huge detection
volumes can be achieved.
Threshold gt 1016 eV
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Renewed efforts along acoustic method for GZK
neutrino detection
Greece SADCO Mediterannean, NESTOR site, 3
strings with hydrophones Russia AGAM antennas
near Kamchatka existing sonar array for
submarine detection Russia MG-10M antennas
withdrawn sonar array for submarine detection
AUTEC US Navy array in Atlantic existing
sonar array for submarine detection Antares RD
for acoustic detection IceCube RD for acoustic
detection
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Present limits on neutrino flux
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MACRO
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FORTE
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AMANDA
depth
Amanda-II 677 PMTs at 19 strings (1996-2000)
AMANDA-II
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AGASA

• AGASA covers an area of about 100 km2 and
  consists of 111 detectors on the ground (surface
  detectors) and 27 detectors under absorbers (muon
  detectors). Each surface detector is placed with
  a nearest-neighbor separation of about 1 km.

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High Resolution Flys Eye HiRes

• HiRes 1 and HiRes 2 sit on two small mountains in
  western Utah, with a separation of 13 km.
• HiRes 1 has 21 three meter diameter mirrors which
  are arranged to view the sky between elevations
  of 3 and 16 degrees over the full azimuth range
• HiRes 2 has 42 mirrors which image the sky
  between elevations of 3 and 30 degrees over 360
  degrees of azimuth.
• At the focus of each mirror is a camera composed
  of 256 40-mm diameter hexagonal photomultiplier
  tubes, each tube viewing a 1 degree diameter
  section of the sky.

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GLUE Goldstone Lunar Ultra-high Energy Neutrino
Experiment
Effective target volume antenna beam (0.3) ?
10 m layer
? 105 km3
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RICE Radio Ice Cherenkov Experiment
South Pole
firn layer (to 120 m depth)
20 receivers transmitters
UHE NEUTRINO ? ? ?
? DIRECTION
E 2 dN/dE lt 10-4 GeV cm-2 s-1 sr-1
at 1017 eV
300 METER DEPTH
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Future limits on neutrino flux
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Mediterranean Projects
2400m
4100m
ANTARES
3400m
NEMO
NESTOR
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NESTOR 1991 - 2000 R D,
Site Evaluation Summer 2002
Deployment 2 floors Winter 2003
Recovery re-deployment with 4
floors Autumn 2003 Full
Tower deployment 2004
Add 3 DUMAND strings around tower
2005 - ?
Deployment of 7 NESTOR towers
ANTARES 1996 - 2000
RD, Site Evaluation
2000 Demonstrator line
2001 Start
Construction September 2002
Deploy prototype line December 2004
10 (14?) line detector complete
2005 - ? Construction of
km3 Detector
NEMO 1999 - 2001 Site selection and RD
2002 - 2004 Prototyping
at Catania Test Site
2005 - ? Construction of km3 Detector
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Baikal km3 project Gigaton Volume Detector GVD
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IceCube

• - 80 Strings
• - 4800 PMT
• Instrumented volume 1 km3
• Installation
• 2004-2010

80.000 atm.? per year
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Pierre Auger observatory
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Telescope Array
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MOUNT
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OWL/EUSO
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ANITA AntarcticImpulsiveTransientArray
Flight in 2006
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SalSA Salt Dome Shower Array
Natural Salt Domes Potential PeV-EeV Neutrino
Detectors
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Renewed efforts along acoustic method for GZK
neutrino detection
Greece SADCO Mediterannean, NESTOR site, 3
strings with hydrophones Russia AGAM antennas
near Kamchatka existing sonar array for
submarine detection Russia MG-10M antennas
withdrawn sonar array for submarine detection
AUTEC US Navy array in Atlantic existing
sonar array for submarine detection Antares RD
for acoustic detection IceCube RD for acoustic
detection
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GLUE
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Neutrinos from UHECR protons
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Why neutrinos from UHE protons?

• All experiments agree (up to factor 2) on UHECR
  flux below cutoff. All experiments see events
  above cutoff!
• Majority of the air-showers are hadronic-like
• Simplest solution for energies 5x1018 eV lt E lt
  5x1019 eV protons from uniformly distributed
  sources like AGNs.

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Active galactic nuclei can accelerate heavy
nuclei/protons
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Photo-pion production
n
p
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Parameters which define diffuse neutrino flux

• Proton spectrum from one source
• Distribution of sources
• Cosmological parameters

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Theoretical predictions of neutrino fluxes

• WB bound 1/E2 protons distribution of sources
  AGN analytical calculation of one point near
  1019 eV.
• MPR bound 1/E protons distribution of sources
  AGN numerical calculation for dependence on Emax
• The g-ray bound EGRET

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EGRET diffuse gamma-ray flux
The high energy gamma ray detector on the Compton
Gamma Ray Observatory (20 MeV - 20 GeV)
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Detection of neutrino fluxes today
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Future detection of neutrinos from UHECR protons
AGN,1/E
/ EUSO
Old sources 1/E2
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Neutrinos from Active galactic nuclei
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Active Galactic Nuclei (AGN)
Active galaxies produce vast amounts of energy
from a very compact central volume. Prevailing
idea powered by accretion onto super-massive
black holes (106 - 1010 solar masses). Different
phenomenology primarily due to the orientation
with respect to us.
Models include energetic (multi-TeV),
highly-collimated, relativistic particle jets.
High energy g-rays emitted within a few degrees
of jet axis. Mechanisms are speculative g-rays
offer a direct probe.
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Neutrinos from AGN core
/ EUSO
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Photon background in core

• Energy scale
• Eg 0.1 10 eV
• Time variability
• t few days or
• R 1016cm
• Model hot thermal radiation.

T10 eV
T1 eV
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Photo-pion production
n
p
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Neutrino spectrum for various proton spectra and
backgrounds
Atm. flux
1/E
E1018eV
1/E2
T1 eV
T10 eV
1/E2
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Most probable neutrino sources
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Optics SDSS. Most powerful objects are AGNs
500 sq deg of the sky, 14 million objects,
spectra for 50,000 galaxies and 5,000 quasars.
Distance record-holder
gt13,000 quasars (26 of the 30 most distant known)
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Low energy radiation from AGN is collimated

• Typical gamma-factor is G 10.
• Radiation is collimated in 1/ G angle 5o in
  forward direction.

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Most of identified MeV-GeV sources are blazars
EGRET 3rd Catalog 271 sources
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Which sources ?

• Blazars (angle energy correlation)

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High energy photons from pion decay cascade down
in GeV region
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Only 22 sources from 66 are GeV - loud
EGRET 3rd Catalog 271 sources
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Which sources ?

• Blazars (angle energy correlation)
• Blazars should be GeV loud (conservative model)

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Which sources ?

• Blazars (angle energy correlation)
• Blazars should be GeV loud (conservative model)
• Optical depth for protons should be large
• t spg ng Rgtgt1

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Bound on blazars which can be a neutrino sources
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TeV blazars does not obey last condition

• Indeed, in order TeV blazars be a neutrino
  sources
• spg ng Rgtgt1
• sgg ng R ltlt1
• spg 6x10-28cm2 while sgg 6.65 x 10-25cm2
• CONTRADICTION!!!

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Which sources ?

• Blazars (angle energy correlation)
• Blazars should be GeV loud (conservative model)
• Optical depth for protons should be large
• t spg ng Rgtgt1
• No 100 - kpc scale jet detected (model-dependent)

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Neutrino production in AGN
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Collimation of neutrino flux in compare to GeV
flux
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Neutrinos from Galactic Supernova
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Possible neutrino signals from Galactic SN in
km3 detector
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Supernova Monitor
Amanda-II
B10 60 of Galaxy A-II 95 of Galaxy
IceCube up to LMC
Amanda-B10
IceCube
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Pointing to Galactic SN

• AMANDA II will see 5-20 events with Egt 1TeV. For
  angular resolution 2o of each event. Pointing to
  SN direction is possible with resolution 0.5o
• For ANTARES pointing is up to 0.1o .
• Compare to SuperKamiokande 8o now and 3.5o
• with gadolinium. HyperKamiokande 0.6o

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Detection of Galactic SN from wrong side by km3
detector

• Atmospheric muons 51010/year or
• 300/hour/(1o)2
• Signal 200 events, besides energy cut 1 TeV.
  
• Angular resolution 0.8o for each event or less
  then 0.1o for SN signal !!!
• (A.Digle, M.Kachelriess, G.Raffelt, D.S. and
  R.Tomas, hep-ph/0307050)

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Neutrinos from exotic UHECR models
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Z-burst mechanism(T.Weiler, 1982)

• Resonance energy E 4 1021 (1
  eV/mn) eV
• Works only if
• mn lt 1 eV
• Mean free path of neutrino is
  L 150 000 Mpc gtgt Luniv

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Cross sections for neutrino interactions
withrelict background n and g
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Pure neutrino sources
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Sources of both g and n
Kalashev, Kuzmin, D.S. and Sigl, hep-ph/0112351
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Gelmini-Kusenko model X-gtnn
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FORTE and WMAP practically exclude Z-burst model
D.S. and G.Sigl, hep-ph/0309328
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Top-down models
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New hadrons (Kachelriess, D.S. and Tortola,
hep-ph/0302161)
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Diffuse neutrino flux

• Flux is unavoidably high due to
• Shape depends on distribution of background
  photons and on proton spectrum

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Conclusions

• Sensitivity of the neutrino telescopes will be
  increased in 102-3 times during next 10 years.
  Now they just on the border of theoretically
  interesting region.
• Secondary neutrino flux from UHECR protons can be
  detected by future UHECR experiments.
• Neutrino flux from AGNs can be detected by
  under-water/ice neutrino telescopes. GeV-loud
  blazars with high optical depth for protons are
  good candidates for neutrino sources.
  
  
  
  
  
  
• Galactic SN can be detected with neutrinos at low
  and high energies.
  
  
• Some of exotic UHECR models will be ruled out or
  confirmed in near future by neutrino data.

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References

• Diffuse neutrino flux. O.Kalashev, V.Kuzmin,
  D.S. and G.Sigl, hep-ph/0205050 D.S. and G.Sigl,
  hep-ph/0309328
• Extragalactic neutrino sources. A.Neronov D.S.,
  hep-ph/0208248
• AGN jet model. A.Neronov, D.S., F.Aharonian and
  O.Kalashev, astro-ph/0201410
• Z-burst model. O.Kalashev, V.Kuzmin, D.S. and
  G.Sigl, hep-ph/0112351
• New hadrons as UHECR. M.Kachelriess, D.S. and
  M.Tortola, hep-ph/0302161
• SN pointing with low and high energy neutrinos.
  R.Tomas, D.S., G.Raffelt, M.Kachelriess and
  A.Dighe, hep-ph/0307050