Exploring EHE Cosmic Rays: Neutrinos and EGMF

1. ArethereEHEsignals?Shigeru Yoshida

2. Outline • EHE CR fluxes – What’s going on? • Revisit EHE particles models • A different approach – Neutrinos! • GZKn + 100 GeV g ?

3. EHE CR fluxes Taken from B.M.Connolly et al 2006 Compiled by S.Yoshida for ICRC 2005

5. Energy estimation Even if detector calibration is perfect… • AGASA(SD) • Rcore 600~1000m • HiRes(FD) • Rcore < Rmoliere ~70m FD SD

6. Fluctuation plays a visible role in the end Hybrid – SD+FD FD-SD Correlation exists! ABSOLUTE value of Energy ?? P.Sommers for Auger collab. (ICRC 2005)

7. Really discrepancy? • Poor Stats --- N(>100EeV) ~ only 11 events • Energy Uncertainty --- D Escale ~ 30% Bayes Factor Test data MC from a single hypothesis BF using AGASA and Auger Spectrum BF using AGASA and HiRes1 Spectrum B.M. Connolly et al PRD 2006

8. Physics may be responsible • EGMF complicates particle trajectories • Source distribution may not be isotropic • Fluctuation in the spectra and intensities • of the source - “cosmic variance”

9. E-2 (rectilinear) E-1 (bohm diffusion) E-1/3 Propagation in EGMF 0.3 mG pancake Energy [EeV] Delay time [yr] Sigl, Lemoine, Biermann, Astropart.Phys. 1999

10. Propagation in EGMF More detailed EGMF model following Large Scale Structure Delay time [yr] Energy [EeV] Sigl, Miniati, Enbelin, PRD 2004

11. Spectrum fluctuated! B 100 nG Sigl, Lemoine, Biermann, Astropart.Phys. 1999

12. Spectrum fluctuated! B 300 nG! More pronounced GZK feature Sigl, Lemoine, Biermann, Astropart.Phys. 1999

13. Astrophysical sources in Large Scale Structures EGMF Baryon Density = Source Density uG nG 20Mpc 20Mpc Observer Sigl, Miniati, Enbelin, PRD 2004

14. Astrophysical sources in Large Scale Structures EHE Sky map Sigl, Miniati, Enbelin, PRD 2004

15. Astrophysical sources in Large Scale Structures Intrinsic fluctuation due to Without EGMF • source intensities • primary spectrum • source density • observer’s location in LSS With EGMF ~ uG Armengaud, Sigl, Miniati,PRD 2005

16. SoMany Unknown Parameters to fit poor data…. • “Favored” Scenario • Source density 2.4x10-5 Mpc-3 • Need LSS? Yes • Observer’s location Void • Mean spectral index -2.4 • B at the observer 8.2 pG But allows many OTHER possibilities…. 

17. Top Down model never dies Beyond the Standard Model • Top-Down neutrinos • decays/interaction of massive particles • (topological defects, SUSY, micro black hole, …) • The main energy range: En ~ 1011-15 GeV X

18. Top Down model never dies Cut-off feature g suppressed by (unknown) URB Sigl, Lee, Bhattacharjee, Yoshida, PRD 1999

19. Top Down model never dies A bunch of n Recycling g in 100 GeV region Sigl, Lee, Bhattacharjee, Yoshida, PRD 1999

20. (EHE) Photons in EBL EM cascades lead to the diffuse g-ray BG in the GeV range Transparent URB Energy Conservation IR/O CMB

21. EHE astrophysics“Everything is transient”“Nothing is certain” • Unknown EGMF strength • Unknown EGMF configuration • Unknown location of us relative to EGMF halo • Unknown source spectra • Unknown source distribution • Unknown source intensity • Large energy scale uncertainty • Extremely low flux • May or may not have a GZK cutoff

22. Neutrinos – The Last Crusader • Forget about EGMF stuff • Propagate cosmological distances – no local effects • EHE g-rays ? - It depends on unknown URB!

23. nm m p nm ne GZKn • The standard scenario EHE-CR • EHE cosmic-ray • induced neutrinos • The main energy range: En ~ 109-10 GeV

24. GZKn Yoshida, Teshima, Prog.Theo.Phys. 1993

25. GZKn – it’s robust Yoshida, Teshima. 1993 Engel, Seckel, Stanev 2001 Compiled by A. Ishihara

26. GZKn – parameter dependences Kalashev et al PRD 2002 Emax, E-a J(E>10 EeV) m, Zmax  J(E<1EeV) Yoshida, Teshima, Prog.Theo.Phys. 1993

27. GZKn – Strong Evolution case • Hard primary proton spectrum • + • strong evolution of sources • Unlikely case, but • Flux >> Waxman.Bahcall • GeV diffuse g OK with EGRAT • Reachable even by present • detectors. Yoshida, Dai, Jui, Sommers ApJ 1997

28. UHE/EHEn fluxes GZK (hard, high Emax) - Kalashev et al 2002 GZK (strong evolution) - ibid GZK (standard) - Yoshida Teshima 1993 TD - Sigl et al 1999 Zburst – Yoshida et al 1998

29. ANITA constraints (projected) Barwick et al PRL 2006 Bound from the 2003flight. Ruled out Z-burst

30. IceCube constraints ~5 yr constraints Look for downgoing or horizontal events. Yoshida, Ishibashi, Miyamoto, PRD 2004

31. IceCubeEHE 9 EeV 100 TeV

32. IceCubeEHE GZK m GZK t Atmospheric m GZK m GZK t Atmospheric m IceCube Preliminary A.Ishihara, S.Yoshida for the IceCube collaboration GZK m0.35events/year GZK t0.31 events/year Atmospheric m0.033events/year

33. EHE Neutrinos + 100GeV g-ray • n channel have its own drawback • low statistics, poor pointing resolutions… • g channel compensates Arrival direction Local UHECR source  VHE g (Ferrigno,Blasi,Marco, Astro.Phys.2005) (Gabici, Aharonian, PRL 2006)

34. (EHE) Photons in EBL Transparent Cooling down to 100 GeV URB Energy Conservation IR/O CMB

35. A “point” source contribution to the diffuse flux Diffuse Flux Flux from A source Source density “R-2” Zmax ~4 m~4 Z~2 (cosmological distances)

36. Too few as UHRCR sources r = 2x10-9 Mpc-3 • Note: • AGASA clusters • rlocal ~10-4~10-5 r = 2x10-7 Mpc-3 ICTs for n point sources? Taken from W. Hofman 2006

37. A “multi-particle” campaign I would like a Munich beer.. Helles ? What are the right ascension/ declination?

38. Summary • EHE signals are Extremely High Epicurean money/time (your career) consuming to explore • Hard to interpret data. Large Scale Structure? r~ 10-5 Mpc-3? • Neutrino may be a rescue Top Down model produces easily-reachable signals. GZK n detection is a probe to cosmological sources. -- Anita, Auger (>10EeV) IceCube (100 PeV-EeV) • Search for 100 GeV g’s with ICTs is worth to try