1. 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

2. Why EeV neutrino To directly identify CR sources Neutrino –Pointing to the source –Avoiding absorption 10 18 eV –Primary >10 19 eV

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: p g interaction p + → m + + n m (~10 -8 s) m + → e + + n e + n m (~10 -6 s) D-resonance: e g ~1 MeV  e n ~10 14 eV. _ e g e p =0.2GeV 2 G 2 e =0.05 e p

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

7. EeV neutrinos:  0 -induced enenenen 100TeV1PeV f   nen2nnen2n WB bound: f   Prompt ~10sec No cooling suppression; 3% WB bound 1EeV

8. HE ’s from neutral  0 production Processes [Li & Waxman 2007b] EM cooling suppression no cooling suppression    CMB

9. Q1: suppressed by e+- production? Q2: deflected by IGM field (hence delayed)? [Li & Waxman 2007b] cross section  -1, similar   above  threshold  n   +2 CMB peak e +- thr.  +- thr.  =10 19-20 eV,  / e =(3-10)%    

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 [Li & Waxman 2007b] [Li & Waxman 2007a] [Li & Song 2004] dn/d e  ~1keV ~1MeV

11. EeV neutrinos: a new channel 0.03 enenenen 100TeV1PeV 0.2 nen2nnen2n WB bound 1EeV [Li & Waxman 2007b] 1 20/km 2 yr 1km 2 experiment n-g association (time/direction): directly identify sources

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