1. Propagation of UHE in Earth Interactions Interactions First Results First Results Implications for the IceCube Implications for the IceCube Future Plan Future Plan Shigeru Yoshida Dept. of Physics CHIBA Univ. CHIBA Univ. Laguna Beach 2003

2. UHE (EeV or even higher) Neutrino Events Arriving Extremely Horizontally Needs Detailed Estimation Limited Solid Angle Window (  N A ) -1 ~ 600 (  /10 -32 cm 2 ) -1 (  /2.6g cm -3 ) -1 [km] Involving the interactions generating electromagnetic/hadron cascades NN  X e + e - Laguna Beach 2003

3. e e      e/     Weak Incoming Products Weak Cascades Decay Weak Pair/decay Bremss Pair PhotoNucl. Decay Pair Pair Bremss Decay Weak

4. Laguna Beach 2003 Cross Sections and the Energy Loss Term CTEQ5 Parton Distribution for the evaluation

5. Laguna Beach 2003

7. Muon-Neutrinos from   Nadir Angle

8. Laguna Beach 2003

9. Tau-Neutrinos from    

10. Laguna Beach 2003 Tau Appearance  pair contribution Suppression By  decay  

11. Laguna Beach 2003

12.  x 1/300

13. Laguna Beach 2003 A factor of 2 enhancement Due to the heavier lepton production

14. Laguna Beach 2003

15. Downward going!! x 1/100!

16. Laguna Beach 2003 Upward-going Regenerating 

17. Laguna Beach 2003

18. Findings…  appeared in EeV-10EeV is our prime target on UHE detection. 1/100-1/500 of primary  intensity! Downward  and  might make main contributions in EeV Energy Estimation would be a key for the bg reduction  in PeV is enhanced due to the heavy lepton Production. Downward  enhanced by the regeneration

19. Laguna Beach 2003 We still need… Absolute Flux and Event Rate Estimation - GZK flux/ Top Down models etc.. - Solid angle integration - Consider Realistic Configuration of the Polar Ice!! including its curvature. IceCube Sensitivity on UHE (horizontal/downward) - R&D Study on the Energy estimation - Needs connection to UHE event generator - Background rejection