1. 2006/6/211 IceCube EHE analysis Our findings and roadmap to analysis Shigeru Yoshida For the EHE working group

2. 2006/6/212 DOM response to high NPEs Log 10 ( ATWD estimated NPE ) Estimated number of photo-electrons per DOM ATWD or FADC? Log 10 (FADC based estimated NPE ) Log 10 (ATWD based estimated NPE ) Log 10 ( FADC estimated NPE) Log 10 (MC Truth NPE ) Red: DOM of which ATWD charge is larger Blue: DOM FADC is larger Npe saturation “ EHE specific ” response!

3. 2006/6/213   NPE Energy Distribution E -1 fluxes contained GZK  Atmospheric  GZK  10 7 10 10 [GeV] Log Npe

4. 2006/6/214 NPE Distribution Distribution difference between the signals and background! Distribution difference between the signals and background! GZK  GZK  Atmospheric 

5. 2006/6/215 Zenith Angle Distribution Signals peak at horizontal direction Background distribute over down-going region GZK  GZK  Atmospheric  up down

6. 2006/6/216 Preliminary Event Selection GZK  Atmospheric  GZK 

7. 2006/6/217 Event Rate with completed detector GZK  0.35 events/year GZK  0.31 events/year Atmospheric  0.033 events/year GZK  GZK  Atmospheric  GZK  GZK  Atmospheric  GZK: S. Yoshida et. al. (1997) ApJ 479:547 (m=4, Zmax=4) IceCube Preliminary

8. 2006/6/218 GZK  Signal Roadmap to analysis Atmospheric  BG Standard Candle In-Ice data 9-strings unblinded data Energy Npe Log(Npe) N DOM Cos(zenith) Log(Npe) Cos(zenith) Log(Npe) IceSim Tune Energy Eff. Area Extrapolate to signal domain Empirical Model

9. 2006/6/219 9-strings working data N pe >10 4 N DOM >80

10. 2006/6/2110 9-strings working data N pe >10 4 ~ 500 Events/yr Needs statistics ! to understand Intensity(N pe, zenith), DOM response in EHE regime

11. 2006/6/2111 Muon bundles 1PeV bundle of 1000 muons (1TeV/muon) Npe only would not be able to resolve tracks We do not know cosmic ray intensity in EHE We do not know cosmic ray composition in EHE Corsika has not reconstructed AGASA/Auger data 9-strings “ EHE ” REAL DATA Log(Npe) Cos(zenith) Build Empirical Model IceSim

12. 2006/6/2112 Why no problem in unblinding? Signal stats in the following data is by far large. Almost independent confirmation!! Expected Event Rate [/year] This Year Y2007 Y2008 x 2 x 1.5

13. 2006/6/2113 Why no problem in unblinding? Background and Signals are so different in Energies (Npe ’ s) and cos(1 st -guess zenith) This cut? Or this cut?

14. 2006/6/2114 Sensitivity/Bound Quasi-differential method S. Yoshida et. al. (2004) Phys. Rev. D 69 103004 Bound: energy dependent!! This is MODEL independent!!

15. 2006/6/2115 Beyond Npe and First-guess Energy/Geometry reco Waveform-based likelihood (proposed by Gary) Utilize unscattered photon hits? (suggested by Lutz in 2004) Including more non-contained events Log(Npe)  Log(Energy) cos(1 st guess  )  cos(reco  )

16. 2006/6/2116 Our Bread and Butter Photo by David Boersma Introducing “ Yoshida ” bottle(s) Your WG wins them if you publish your results earlier than anybody else!