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10 18 eV Neutrinos associated with UHECR ( >10 19 eV ) sources

10 18 eV Neutrinos associated with UHECR ( >10 19 eV ) sources. Zhuo Li ( 黎卓 ) Peking University, Beijing Collaborators: Eli Waxman & Liming Song. Li & Waxman, arXiv:0711.4969. Why EeV neutrino. To directly identify CR sources Neutrino Pointing to the source Avoiding absorption

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10 18 eV Neutrinos associated with UHECR ( >10 19 eV ) sources

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  1. 1018eV Neutrinos associated with UHECR (>1019eV) sources Zhuo Li (黎卓) Peking University, Beijing Collaborators:Eli Waxman & Liming Song Li & Waxman, arXiv:0711.4969

  2. Why EeV neutrino • To directly identify CR sources • Neutrino • Pointing to the source • Avoiding absorption • 1018eV • Primary >1019eV

  3. HE Neutrinos from CR accelerators • -production in accelerators: • acc. p’s; acc. e’s : synchrotron/IC photons • If all p energy converted to  (in the source) • Waxman-Bahcall Bound for sources optically thin to p: Waxman & Bahcall 1999

  4. UHECR source: acceleration

  5. GRB HE n’s: pg interaction p+→ m+ + nm (~10-8s) m+→ e+ + ne+ nm(~10-6s) _ e=0.05ep eg ep=0.2GeV2G2 • D-resonance: • eg~1 MeV en~1014eV.

  6. Spectral cutoff: EM cooling • For >10PeV protons, the fraction of total energy loss • Suppressed by pi+/mu+ EM energy loss • life, tcool1/ en2n(en) f=0.2 [Waxman & Bahcall 1997] ~1PeV 100TeV Neutrino energy No UHE neutrinos, how to identify UHECR sources? [Kashiti & Waxman 2005; Rachen & Meszaros 1998]

  7. EeV neutrinos: 0-induced en2n WB bound: f=1 f=0.2 No cooling suppression; 3% WB bound Prompt ~10sec 100TeV 1PeV 1EeV en

  8. HE ’s from neutral 0 production p0 • Processes g CMB EM cooling suppression m n no cooling suppression [Li & Waxman 2007b]

  9. q n lm g CMB peak n+2 • Q1: suppressed by e+- production? • Q2: deflected by IGM field (hence delayed)? cross section -1, similar above  threshold e+- thr. +-thr. =1019-20eV, /e=(3-10)% [Li & Waxman 2007b]

  10. Q3: HE ’s escape from source? • Attenuated by e+- production in source • low energy break • KN suppression of cross section • Strong synchrotron absorption below keV • Conclusion: >10PeV photons don’t suffer attenuation dn/de [Li & Waxman 2007b] ~1MeV ~1keV e [Li & Waxman 2007a] [Li & Song 2004]

  11. EeV neutrinos: a new channel en2n WB bound 1 0.2 20/km2yr 1km2 experiment 0.03 100TeV 1PeV 1EeV en n-g association (time/direction): directly identify sources [Li & Waxman 2007b]

  12. Coherence radio Cerenkov: • ANITA (balloon) • ARIANNA (array) • ~1/yr expected [Barwick 2007]

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