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UHE Neutrino Astronomy. Shigeru Yoshida Chiba University http://www-ppl.s.chiba-u.jp/~syoshida/. RESCEU 2003. RESCEU 2003. Outline. UHE n emission – What it can tell Theoretical Bound of n fluxes Extremely High-Energy n generation Cosmic n detection – the current status
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UHE Neutrino Astronomy Shigeru Yoshida Chiba University http://www-ppl.s.chiba-u.jp/~syoshida/ RESCEU 2003
RESCEU 2003 Outline • UHE n emission – What it can tell • Theoretical Bound of n fluxes • Extremely High-Energy ngeneration • Cosmic n detection – the current status • IceCube : reachable to EHE n universe
n / / / / / / / / / / / / / / / / / TeV sources! cosmic rays
Physics motivation • origin and acceleration of cosmic rays • understand cosmic cataclysms • find new kind of objects? • neutrino properties ( , cross sections ..) • dark matter (neutralino annihilation) • tests of relativitiy .... • search for big bang relics ... • effects of extra dimension etc. ...
Active Galaxies: Jets 20 TeV gamma rays Higher energies obscured by IR light VLA image of Cygnus A
black hole radiation enveloping black hole
You cannot expect too many n! TeV/EGRET observations !! Cosmic Ray observations! Synchrotron cooling p g (p,n) p 2g m n en n You cannot expect too high energies
DUMAND test string NT-200 FREJUS MACRO Theoretical bounds Suppressed by Synchrotron Cooling opaque for neutrons MPR neutrons can escape atmospheric W&B Mannheim, Protheroe and Rachen (2000) – Waxman, Bahcall (1999) derived from known limits on extragalactic protons + -ray flux
EHE(Extremely HE) n Synchrotron cooling of m … Production sites with low B Intergalactic space!! • GZK Production • Z-burst • Topological Defects/Super heavy Massive particles
GZK Neutrino Production 0.6 x 10-27 cm2 2.725 K 411 photons / cm3 π ν + + γ μ + ν e p γ p n E = 10 20 eV Conventional Mechanism of EHE neutrinos!! E 0.8 x 10 20 eV ~
GZK n fluxes Yoshida and Teshima 1993 Yoshida, Dai, Jui, Sommers 1997 RESCEU 2003
Orientative order of magnitude [1-3] [3-5] [1-4] [0.2-1] [50-80 Km/s/Mpc] [B≤1nG] [?] [E max >4 1020 eV] Parameters involved in calculation. Predicted fluxes. Parameters γspectral injection index m activity evolution index zmaxz of formation of sources ΩMdensity of matter HoHubble constant Bintergalactic magnetic field ηLρL/ηoρolocal enhancement Emaxmaximum acceleration energy in source (Diego González-Díaz, Ricardo Vázquez, Enrique Zas 2003) RESCEU 2003
(Diego González-Díaz, Ricardo Vázquez, Enrique Zas 2003) CR and νfluxes for different models RESCEU 2003
EHE Constraints by CR/g Deciding factors • Source Evolution • Extension of source distribution • Local source enhancement?
Z-burst constraints RESCEU 2003 (Yoshida, Sigl, Lee 1998)
EHE Neutrino Fluxes RESCEU 2003
RESCEU 2003 Cosmic UHE n detection Neutrino Telescopes – Antares, AMANDA, IceCube etc.
Infrequently, a cosmic neutrino is captured in the ice, i.e. the neutrino interacts with an ice nucleus • In the crash a muon (or electron, • or tau) is produced Cherenkov light cone muon interaction Detector • The muon radiates blue light in its wake • Optical sensors capture (and map) the light neutrino
Optical CherenkovNeutrino Telescope Projects ANTARES La-Seyne-sur-Mer, France BAIKAL Russia NEMO Catania, Italy DUMAND Hawaii (cancelled 1995) NESTOR Pylos, Greece AMANDA, South Pole, Antarctica
ANTARES Deployment Sites Thetys Marseille La Seyne sur Mer Toulon Existing Cable Marseille-Corsica Demonstrator Line Nov 1999- Jun 2000 42°59 N, 5°17 E Depth 1200 m New Cable (2001) La Seyne-ANTARES ANTARES 0.1km2 Site 42°50 N, 6°10 E Depth 2400 m ~ 40 deployments and recoveries of test lines for site exploration 0.1 km2 Detector with 900 Optical Modules , deployment 2002- 2004
ANTARES Layout • 12 lines • 25 storeys / line • 3 PMT / storey 14.5 m 350 m Junction box 100 m 40 km to shore ~60-75 m Readout cables
Optical beacon t2 t1 t3 Cylinder Optical fibres Laser Optical Splitter Laser calibration at the CPPM dark room
Optical module 1996-2000 AMANDA II Detector Amundsen-Scott Station South Pole
O(km) long muon tracks Electromagnetic and hadronic cascades 15 m ~ 5 m direction determination by cherenkov light timing Detection of e , ,
talk HE 2.3-4 cascades (2000 data) Excess of cosmic neutrinos? Not yet ... .. for now use number of hit channels as energy variable ... muon neutrinos (1997 B10-data) accepted by PRL „AGN“ with 10-5 E-2 GeV-1 cm-2 s-1 sr-1 cuts determined by MC – blind analyses !
talk HE 2.3-5 above horizon: mostly atmospheric ‘s below horizon:mostly fake events sky subdivided into 300 bins (~7°x7°) Point source search in AMANDA II Search for excess events in sky bins for up-going tracks PRELIMINARY 697 events observed above horizon 3% non-neutrino background for > 5° cuts optimized in each declination band no clustering observed - no evidence for extraterrestrial neutrinos ...
DUMAND test string NT-200 FREJUS AMANDA-97 NT-200+ AMANDA-II IceCube AMANDA-00 MACRO Theoretical bounds and future opaque for neutrons MPR neutrons can escape atmospheric W&B Mannheim, Protheroe and Rachen (2000) – Waxman, Bahcall (1999) derived from known limits on extragalactic protons + -ray flux
IceTop AMANDA South Pole Skiway 1400 m 2400 m IceCube Talks/Poster by H. Miyamoto this evening • 80 Strings • 4800 PMT • Instrumented volume: 1 km3 (1 Gt) • IceCube is designed to detect neutrinos of all flavors at energies from 107 eV (SN) to 1020 eV
IceCube (1km3 underground observatory) • Sensitive to 10-2 ~ 10-3 of the WB bound • EHE( ~EeV) n -- Almost reachable! GZK, Z-burst, TD... New Physics? Secondary m/t detection
How EHE events look like Eµ=10 TeV ≈ 90 hits Eµ=6 PeV ≈ 1000 hits The typical light cylinder generated by a muon of 100 GeV is 20 m, 1PeV 400 m, 1EeV it is about 600 to 700 m.
EHE (EeV or even higher) Neutrino Events Arriving Extremely Horizontally • Needs Detailed Estimation • Limited Solid Angle Window (srNA)-1 ~ 600 (s/10-32cm2) -1(r/2.6g cm-3) -1 [km] Involving the interactions generating electromagnetic/hadron cascades mN mX e+e- RESCEU 2003
Products ne nm nt m t p e/g ne Weak Weak nm Weak Weak nt Weak Weak Incoming e/g Cascades Decay Weak Pair/decay Bremss Decay m Pair Pair PhotoNucl. DecayPair Decay Pair Bremss Decay Decay Decay Decay Weak t Pair PhotoNucl. p Cascades
Suppression By t decay Muon(Neutrinos) from nm nt Tau(Neutrinos) from nm nt Nadir Angle RESCEU 2003
Atmospheric muon! – a major backgrond But so steep spectrum Upward-going Downward going!! RESCEU 2003
± π + + e e - - e e ν EHE events! Downward lepton 1.4km γ γ 1km Ice γ ν lepton 1km Rock ν Upward
11000m 2800 m 1400 m Down-going events dominate… Atmospheric m is attenuated faster… Up Down RESCEU 2003
Flux as a function of energy deposit in km3 • dE/dX~bE DE~DXbE
Flux as a function of energy deposit in km3 • dE/dX~bE DE~DXbE
Intensity of EHE m and t [cm-2 sec-1] RESCEU 2003
IceCube EHE n Sensitivity 90% C.L. for 10 year observation
RESCEU 2003 Summary • UHE n fluxes are constrained by g/CR fluxes. A detection beyond this limit would imply a new class of astronomical objects. • EHE n fluxes are constrained by EGRET g/UHECR fluxes and by the synchrotron cooling of m’s. The loophole to this bound would be the GZK cosmogenic neutrinos with intensity of 10-7~10-8 GeV /cm2 sec sr.
RESCEU 2003 Summary (Cont’d) • AMANDA observatory is getting to reach to its sensitivity to the WB bound. The other telescopes in northern hemisphere would reaches the similar sensitivity. • IceCube observatory would be sensitive to 10-2 of the WB bound. The EHE sensitivity is comparable to the GZK neutrinos fluxes: 3x10-8 GeV /cm2 sec sr in 10 years observation.