ARENA 2005 DESY-Zeuthen Conference Summary 19 May 2005

1. ARENA 2005 DESY-ZeuthenConference Summary19 May 2005 John Learned University of Hawaii

2. General Comments • Heroic times for radio and acoustic, a renaissance… will grand discoveries follow? • Adventurous field: dangerous for careers perhaps, but opportunities, and a great training ground for students. • Build on successes of optical Cherenkov in IMB, Kam, SuperK -> SN1987A & muon neutrino oscillations. • Long campaign of Baikal, DUMAND-US, AMANDA, NESTOR, ANTARES, and NEMO ->ICECUBE… (+KM3?) Soon to bear fruit. • We had all better wish ICECUBE great success! • Amazingly all highest energy Nu limits from radio and acoust!! • Limits easier than discoveries… knowing what you saw is vital. • But no UHE discoveries yet, though… no Xterr nus.. Danger; lessons of HE and VHE Gamma Ray Astron. • Seek bread and butter results, ties to particle physics, creative funding. • International cooperation vital and natural. John Learned at ARENA 2005

3. Several Random Comments on Historyadding to earlier remarks here and at RADHEP • M. A. Markov & Frederick Reines – great stimulators of neutrino physics (and nucleon decay….), roles perhaps underappreciated. • Mistakes often forgotten… early acoust overestimate, other acoustic mechanisms with large output… progress is a crooked path. Amusing how wrong results can initiate later successes. • Some positive surprises: water and ice transparency >> thought in 1980’s. John Learned at ARENA 2005

4. Requirements for UHE Rare Particle Detection • Need natural targets, natural radiation mechanisms, detection at large impact parameter • Aevent ~ (Λtransverse)2 = (Λatten/θ)2 • Methods Particle Sampling Fluorescence/Scintillation Optical Cherenkov Radio Cherenkov Radio Geo-Synchrotron Thermo-Acoustic Radiation John Learned at ARENA 2005

5. Project Summary • So many projects and talks at this meeting, cannot cover all in short summary…. Apologies. • See many wonderful talks on ARENA web. • Many starting, a few physics results… • See following table… John Learned at ARENA 2005

6. Methods & Projects for UHE Particle Detection John Learned at ARENA 2005

7. Physics Simulations • Great progress in all areas (GEANT4 + Corsika)… but much to do for solids both acoustic and radio. • Highest energies still not well handled. Computing time. LPM. (Dedenko made nice hybrid). • Time domain in radio needed. • Need studies of HEP potential… crossections, flavor separation, composition…. • Have lab demos for radio, need work on acoust. • HE Physicists need to learn to deal with analogue signals… interesting new options in signal processing • (Engineers need to learn about non-CW signals). John Learned at ARENA 2005

8. Detector Technology • Much progress in radio antennas, work ongoing… still some black magic. • Ongoing problem due to our special need for impulse response devices. • Piezoelectric technology well developed by military & oil industry… commercial devices available. Use it. • Interesting options with fiber optics (Trono). John Learned at ARENA 2005

9. On Site Simulators & Calibrators • Pingers (bulbs) and transmitters (sparkers) easy, but shower simulation is not. • Sadly, no physics benchmark. • Shower simulators under development for acoust (zapper, laser). • Need ideas for ice/salt radio (accel in hole ?). • Cross calibrate in radio EAS applications. John Learned at ARENA 2005

10. Media Properties • Need work in all areas… • Radio in ice ~ good, lots of variation in salt measurements, but probably OK. • Acoust well known in water, but ice mostly theory. • More work needed in accounting for variable index of refraction, in simulations. John Learned at ARENA 2005

11. Radio Atten in Salt- lots of spread John Learned at ARENA 2005 Chiba

12. Acoustic absorption in ocean Pure water absorbs due to its viscosity. In sea water, a pressure wave shifts chemical equilibrium between a molecule and ions, taking energy from wave: B(OH)3 = B3+ + 3 OH-(relaxation freq. ≈ 1 kHz)MgSO4 = Mg2+ + SO42-(relaxation freq. ≈ 100 kHz) John Learned at ARENA 2005 water + B(OH)3 + MgSO4 absorptivity [dB/km] water + MgSO4 water Ulrich Frequency [Hz] Price

13. Summary of Acoustic predictions for iceand NaCl scattabs 104 Hz 3x104 Hz 104 Hz 3x104 Hz Ice (D=0.2 cm) 1650 km 20 km 8-12 km 8-12 km NaCl (D=0.75 cm) 120 km 1.4 km 3x104 km 3300 km 1. Clay, liquid inclusions, and anhydrite in salt domes dominate scattering and absorption. 2. Scattering in salt domes is worse than in South Pole ice because grain size is larger (geometric rather than Rayleigh). 3. In ideal salt, absorptivity would be far lower than in ice; in real salt it will be worsened by heterogeneities. 4. Must measure scattand abs in South Pole ice and salt domes John Learned at ARENA 2005 Price

14. Predicted depth (temperature)-dependent ice acoustic absorption at ~10 kHz See P.B. Price’s talk: absorption frequency-independent but temperature (depth)-dependent John Learned at ARENA 2005 In simulation, integrate over absorption from source to receiver Vandenbroucke

15. Ocean Acoustic Arrays Can Compete not optimized yet John Learned at ARENA 2005

16. Acoustic Detection Needs • Need acoustic noise levels in ocean versus depth, direction. • Realistic ocean propagation modelling. • Survey of promising locations in ocean (deep, calm, salty, warm surface, possibility to work below reciprocal depth). • Acoustic absorption and scattering in ice and salt, measured in situ. • Study of shear wave production in salt and ice. • Investigate use of surplus telephone (fiber) cables for a mid-ocean array. John Learned at ARENA 2005

17. LOPES@KASCADE-GrandeHeino Falcke KASCADE: ~250 electron & muon scintillator detector hutsLOPES10: 10 radio antennas KASCADE Grande: expansion of KASCADE (red dots) John Learned at ARENA 2005 KASCADE … KASCADE Grande

18. LOPES Summary & ConclusionsHeino Falke • LOPES works, the geosynchrotron effect is real • Radio is a faithful tracer of air showers • Radio gives very good energy information and arrival directions. • Inclined showers: Excellent prospects for composition studies and neutrino hunting • Next steps: Argentina, Moon John Learned at ARENA 2005

19. Westerbork Proposed Experiment next 5 slides from Jose Bacelar Use Westerbork radio observatory • Advantages: • 117-175 MHz band • 25 m diameter dishes • 5 degree field of view • 12-14 coincident receivers • 100 hour observation time • 40 M samples/sec (PuMa2) • Polarization information John Learned at ARENA 2005

20. Results of calculations for cosmic rays: John Learned at ARENA 2005

21. Results of calculations for neutrinos: John Learned at ARENA 2005

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23. Calc. limits GLUE Published limits Rice,GLUE,FORTE John Learned at ARENA 2005 Predicted limits 45 days ANITA Theoretical predictions Active galactic nuclei Astro.Phys.3(96)295 GZK induced flux Phys.Rev.D64(04)93010 Topological defects AstroPhys. J. 479(97)547 Calc. limits 100 hours Westerbork

24. Strong refraction in firn Acoustic: upward Radio: downward [D. Besson] John Learned at ARENA 2005 Signals always bend toward minimum propagation speed, but: Sound abhors vacuum [c =0] Radio adores vacuum [c = 3e8 m/s] Vandenbroucke

25. Ice Optical, radio, acoustic independent effective volumes John Learned at ARENA 2005 Preliminary! Vandenbroucke

26. Conclusion • Wonderful level of activity in AR detection. • New ideas, ranging from deep ice and salt, to earth and sky. • Exciting rapid progress in radio EAS • Much work to do in studying media, technology, array design, simulations. • Some projects close to having crucial results (ANITA, ICECUBE, AUGER). • Many thanks to hosts, and looking forward to next meeting. • Advert: (MeV) Geonu meeting in Hawaii 14-16 Dec 2005. John Learned at ARENA 2005

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28. John Learned at ARENA 2005 ARENA 2006Newcastle UK

29. Location John Learned at ARENA 2005

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34. EHE CR NusAndreas Ringwald – DESY • Insert slides limits and spectrum • SM Crossection uncertainties ~x2 • New physics x 100 E>EeV? • Strongly interacting nus… depth of interaction? • Necessity of seeing something soon or we are in trouble…. John Learned at ARENA 2005

35. GZK NeutrinosDave Seckel • Show overall spectrum and limits • ESS benchmark, but could be 10x lower, or 10x higher depending upon evolution, spectrum,… John Learned at ARENA 2005

36. Compare MethodsJulia Becker • Show plots energy and depth • What geomoetric volume for ICECUBE? John Learned at ARENA 2005

37. Radio Attenuation in Salt and IceChiba • L = 538 +/- 171 m in pure salt, cavity method 1GHz, 1000+/- 640 m at 300 MHz • Hockley 275+/- 234 m peculiar spread, 156+/-112m at 300MHz?? Show atten vs freq plot Questions of water absorption and polycrystaline form John Learned at ARENA 2005

38. Acoustic Waves in Ice and SaltBuford Price • Absorption and scattering both look good for ice and salt (10 km scale, but salt 1km?) • Salt needs dome with small (<1cm) grains • Need in situ measurements • Temperature and pressure dependence? John Learned at ARENA 2005

39. Acoustics in SaltEisenblatter and Manthei • Crack monitoring around cavities… 10KHz • Peak attenuation around 0.28db/10m in German repository (500m deep). John Learned at ARENA 2005

40. Radio Signals in Test Beams at SLAC Dawn Williams & Ped Miocinovic • 2000 – sand, 2002 – salt • photon beam simulated 1015 – 1019 eV • Amplitude and polarization agrees with theory over large range. • Measurements of spectrum, phase and deconvolved time domain consistent. John Learned at ARENA 2005

41. UHE SimulationsL. G. Dedenko • Hybrid calculations producing results • 400 m at 1020 eV due to LPM • Show cascade length vs energy John Learned at ARENA 2005

42. Coherent Radio Emission in Solid MediaJaime Alvarez-Muniz • ZHS, GEANT4 agree in various media • Simple scaling model for various media John Learned at ARENA 2005

43. Structure Function of Charge Excess in Rock SaltY. Watanabe • Model of EM shower with parameters for both longitudinal and lateral densities. • Uses GEANT4 up to few PeV. John Learned at ARENA 2005

44. Radio from CR ShowersHuege & Falcke • Geomagnetic effect predominates • Scales roughly with energy over large range • Frequencies < 50 MHz, dists < 1km • Not strong variation with azimuth around track • Show plots John Learned at ARENA 2005

45. EAS Radio Simulations with EGSnrcA. Konstantinov • See diffraction from Cherenkov • Cherenkov and Geosynchrotron… latter dominates by x10 • Cherenkov becomes dominant >100 MHz John Learned at ARENA 2005

46. Radio Signal Pulse ShapesDavid Seckel • Scaled to universal shapes for long and trans • Uses gamma functions for shower model • How to handle flcutuations, phases,… John Learned at ARENA 2005

47. Acoustic Signal ProcessingSean Danaher • Nice review of various signal analysis techniques…. See talk. John Learned at ARENA 2005

48. Experience from SAUNDJason Vandenbroucke John Learned at ARENA 2005

49. Analysis of ITEP Baikal Acoustic DataD. Zaborov • Doing reconstruction of possible sources of EAS generated pulses • No correlated events with EAS counters • Threshold maybe 1021 eV? John Learned at ARENA 2005

50. Acoustic Detectors in AntaresC. Neumann • Developing piezo devices • Deployed recording device • Have some noise spectra, but peculiar • Crazy plan to use sensors on glass housing John Learned at ARENA 2005