25 June, 2006 UHE Neutrinos: II D. Seckel, Univ. of Delaware

UHE Models, Erice, 25 June 2006 (Seckel) Topics Models w/focus on GZK Radio concept Coherent Radiation from Showers Radio/Acoustic Model independent limits

UHE Models, Erice, 25 June 2006 (Seckel) Overview of UHE models Proton acceleration models & UHE neutrinos Top-down scenarios Focus on GZK –Techniques –Cosmic evolution & model parameters –Reasonable, Guaranteed?

UHE Models, Erice, 25 June 2006 (Seckel) Neutrinos from accelerated protons Lots of evidence for shock acceleration –SN remnants & TeV  ’s –AGN, GRB,  -quasars, etc. Power law spectrum –E -2, maybe a bit softer E  ~ 1/20 E p

UHE Models, Erice, 25 June 2006 (Seckel) UHE Production: Acceleration 1. Acceleration predictions depend on scenario – could be “no ’s”. 2. “GZK” neutrinos are guaranteed – a guide for experiment design. 3. Still some model dependence. 4. Constraints from EGRET & UHECR 5. E ~.05 E p

UHE Models, Erice, 25 June 2006 (Seckel) Waxman & Bahcall “limit” Assume –Relativistic shock limit –Flat, i.e. equal energy per decade Normalize to UHE GeV –Above Galaxy –Below GZK Yield 1 neutrino per proton –  =1 source ? –Neutron escape v. acceleration Not a “limit” – think of as scale due to energy budget

UHE Models, Erice, 25 June 2006 (Seckel) Top down models

UHE Models, Erice, 25 June 2006 (Seckel) Jet Fragmentation 1.Mesons & Baryons created with same E distribution 2.Mesons more numerous by and  fluxes much higher than for “bottom up” color

UHE Models, Erice, 25 June 2006 (Seckel) UHE production: top down 1. For “direct” production, E > E p 2. #direct > #p 3. Constraints from EGRET 4. “GZK” there, but unimportant

UHE Models, Erice, 25 June 2006 (Seckel) Typical summary of models

UHE Models, Erice, 25 June 2006 (Seckel) GZK neutrinos CMBR is observed Cross-sections are known Lorentz invariance These exist (AGASA, HiRes, Auger..) Robust prediction for and 

UHE Models, Erice, 25 June 2006 (Seckel) GZK cosmic cascade codes propagation & dE/dx –adiabatic (cosmic expansion) –photonuclear:  p  B+X (ESS use SOPHIA) –pair production:  p  pe + e - source characteristics –injection spectrum dN/dE ~ E -(1+  ) –source cutoff E c –luminosity (ESS – normalize to UHECR, KKSS limit from EGRET) –homogenous cosmology –integrate over red-shift –source evolution: (1+z) m, z max –H 0,  …

UHE Models, Erice, 25 June 2006 (Seckel) dE/dx (  p  B+X (SOPHIA)) E / E p E / E em More to life than the  -resonance

UHE Models, Erice, 25 June 2006 (Seckel) Neutrino yield e  p

UHE Models, Erice, 25 June 2006 (Seckel) Spectrum and source evolution Simple scaling with m,  for matter dominated Shift energy of yield with epoch Change magnitude of yield with epoch q = 1 + z Factors of q for p and 

UHE Models, Erice, 25 June 2006 (Seckel) Simple scaling of GZK Spectrum: (E p ) -(1+  ) Evolution (1+z) m Matter dominated cosmology (1+z) -5/2 Spacing  (ln q) = 1 dB Shape of Y changes with   =1.5, m = 0  =1.0, m = 0.5  =1.0, m = 0  =1.5, m = 3

UHE Models, Erice, 25 June 2006 (Seckel) ESS result for a “reasonable” model Model –m=3, z max = 1.9, flat to 2.7, rolloff for z > 2.7. –Log E c = 21.5 –Norm. (19 < Log E cr < 21) –  = 0.0, 0.7 –  = 1 (E -2 spectrum) Flux “grazes” WB   e n-decay for anti- e

UHE Models, Erice, 25 June 2006 (Seckel) Discussion: Degeneracy of UHECR models a)Flat spectrum, evolution, galactic contribution b)Steep spectrum, no evolution, no galaxy

UHE Models, Erice, 25 June 2006 (Seckel) Neutrinos break degeneracy a) Flat spectrum, evolution, galactic contribution b) Steep spectrum, no evolution, no galaxy

UHE Models, Erice, 25 June 2006 (Seckel) Range of GZK possibilities ESS: m=3,  =1 ESS: m=0,  =1.7 KKSS: max

UHE Models, Erice, 25 June 2006 (Seckel) Summary of flux models & GZK Wide range of models for UHE neutrino production –WB reasonable baseline for UHE Top-down models give extra at high energy GZK mechanism is consequence of UHECR observations –Robust prediction of UHE CR –ESS is reasonable LOM – “Least Objectionable Model” GZK is a cosmology experiment –Source models give ± 1 order of magnitude uncertainty –“multi-wavelength”: UHE CR + UHE may resolve source issue

UHE Models, Erice, 25 June 2006 (Seckel) Radio Concept (with RICE as an example) Radio detection of showers RICE –Concept –Daq –Flux limit

UHE Models, Erice, 25 June 2006 (Seckel) Radio Techniques 5 m Askaryan: Q s = N e- - N e+ ~ 0.25 (E s /GeV)  c = 56 o +/- 3 o Detection distance scales with E s until ice absorption kicks in (1 km)

UHE Models, Erice, 25 June 2006 (Seckel) Confirmed at SLAC SLAC T444, Saltzberg et al. PRL 2001 SLAC T460, Gorham et al. 2002

UHE Models, Erice, 25 June 2006 (Seckel) RF Detection (RICE version) 5 km ~ 10 PeV event ~ 10 EeV event 600 m

UHE Models, Erice, 25 June 2006 (Seckel) RICE (very basic) channel and DAQ configuration Power Scope Trigger generator Antenna Amp in PV cable AmpFilter Splitter PC 4 hits within 1200 ns Latch scope TDC times to PC On-line veto (TDC times) Read scope Write to disk 8  sec 1 ns sample 500 MHz

UHE Models, Erice, 25 June 2006 (Seckel) RICE Flux Limits

UHE Models, Erice, 25 June 2006 (Seckel) Coherent Radiation from Showers Current density v. sum over single particles Review MC calculations Scaling of universal shape Application to AVZ Hadronic showers Different media Phases & pulse shapes Other issues

UHE Models, Erice, 25 June 2006 (Seckel) RF calculations: J v. sum of particles Current source density –Pro: Formal analytic relations Scaling –Con: Currents not known Sum over particles –Pro: Linear sum MC techniques –Con: Redo for each case Computationally expensive at high E.

UHE Models, Erice, 25 June 2006 (Seckel) Radiation from single particles ZHS: 2 0.5

UHE Models, Erice, 25 June 2006 (Seckel) Sum over particles/Integrate over shower Shower Front + Light Cone Density of Excess Projected Track Length

UHE Models, Erice, 25 June 2006 (Seckel) Separation of Variables

UHE Models, Erice, 25 June 2006 (Seckel) Phases for y,z transforms

UHE Models, Erice, 25 June 2006 (Seckel) Normalization and Determination of f, G y, G z

UHE Models, Erice, 25 June 2006 (Seckel) AVZ (Alvarez-Muniz, Vazquez, Zas) AVZ Use a Gaussian, and give the half-width of the Cerenkov cone at 1 GHz as 3.72 ° for a 1 PeV (3.1 m) shower. Determine G z as FT of gaussian

UHE Models, Erice, 25 June 2006 (Seckel) Scaling vs AVZ Field calculation is integral over shower profile Separation of shower profile Separation of form factors With scaled frequencies Adapted from Alvarez, Vazquez, Zas “Full sim” is approx a Blue – Gaussian for f(z), AVZ approx c for G y Red – Griessen for f(z) Separation of phase factors

UHE Models, Erice, 25 June 2006 (Seckel) Scaling with energy and type. (AZ) 1. LPM effect (Note: limited at ~10 20 eV by  p interactions (BR,K)) 2. At PeV proton showers are longer 3. Hadronic shower size asymptotes at about 93% of e-shower

UHE Models, Erice, 25 June 2006 (Seckel) LPM effect & Hadronic showers LPM lengthens shower –Narrows Cherenkov cone E < 1 EeV e CC showers y =.8 E > 1 EeV hadronic-showers – y =.2 –3 flavors * (CC + NC) = 4.5 channels –No LPM - no  0 decay above a few PeV (coincidence).

UHE Models, Erice, 25 June 2006 (Seckel) Hadronic showers II. (HM) Excess charge 1 GHz Contained Wider in  suggests shorter shower. Size similar to AZ Same R M ? (Affects G y ) – also see S. Klein Difference between proton and jet (G z )? What about charm (~10%)?

UHE Models, Erice, 25 June 2006 (Seckel) Scaling with medium AVZ scaled G4: From S. Hussain Yield of projected track length

UHE Models, Erice, 25 June 2006 (Seckel) Phases & Pulse shapes Hussain: G4 10 TeV shower, reconstructed complex E(  ) at  FFT  E(t) If  (t) symmetric, G z is real,  =0. i G z will transform to time derivative of  will be bipolar symmetric. If not, then  0, asymmetric shape. Changes sign with . Comparison to AVZ scaled at  =4. AVZ pulse shape symmetric bipolar. Comparison shown with and Without filter

UHE Models, Erice, 25 June 2006 (Seckel) Gamma is a better pulse shape Without phases AVZ effectively gaussian shower profile. Gamma function is approximation to shower profile. Causal, analytic phase, easy to scale. Comparison to G4

UHE Models, Erice, 25 June 2006 (Seckel) Determine G y, G z from G4 shower & test Spectrum at  from Hussein. Use  = 0 to get f 0, G y Use  = -2 to get G z  = (-4,2,4) from scaling, with phase part of G z GyGy GzGz

UHE Models, Erice, 25 June 2006 (Seckel) Multiple showers & fluctuations e CC events Multiple interactions Model fluctuations by adding subshowers from beginning of shower ? Fluctuations from distribution a,b ?

UHE Models, Erice, 25 June 2006 (Seckel) Acoustic Same as radio…. except –scalar vs vector –total track length –v/c is (a bit) smaller –Attenuation is different –experiment bandwidth See more information in talk by C. Spiering

UHE Models, Erice, 25 June 2006 (Seckel) Acoustic detection contours in ice (Vanderbroucke) Contours for P thr = 9 mPa: raw discriminator, no filter

UHE Models, Erice, 25 June 2006 (Seckel) Radio & Acoustic Radio –Ice: in-situ (RICE, AURA, …) –Ice: remote (ANITA, FORTE, Europa) –Salt: in-situ (SALSA) –Rock: remote (GLUE, NuMoon, LORD, …) Acoustic –Water (SAUND, ACOR E, KM 3 ) –Ice ( SPATS, Hybrid IceCube Extension: (ORA))

UHE Models, Erice, 25 June 2006 (Seckel) Antarctic Impulsive Transient Antenna (ANITA) Peter Gorham

UHE Models, Erice, 25 June 2006 (Seckel) ANITA-Lite: Dec ’03-Jan ‘04 TIGER/ANITA-lite flight path, 18d 5hr duration

UHE Models, Erice, 25 June 2006 (Seckel) ANITA-lite

UHE Models, Erice, 25 June 2006 (Seckel) SLAC

UHE Models, Erice, 25 June 2006 (Seckel) In-ice AURA Askaryan Underice Radio Array Long term goal Design issues

UHE Models, Erice, 25 June 2006 (Seckel) 10 year goals Completed Detector –1000 km 3 sr –E thr < 1 EeV (10 9 GeV) 100 events/yr from GZK –Full sky spectrum above 1 EeV –Event/Flavor ID –Measure   –Point source, GRB detection …

UHE Models, Erice, 25 June 2006 (Seckel) Attenuation & horizontal spacing eff includes temperature profile to bottom. Data from Barwick et. al. Maximum Spacing < 2 km

UHE Models, Erice, 25 June 2006 (Seckel) Cerenkov cone & vertical spacing 10 deg * 2 km = 300m Maximum separation < 300 m LPM effect for UHE e-showers3 deg width for hadronic or EHE e-showers

UHE Models, Erice, 25 June 2006 (Seckel) Ray tracing & Depth Minimum Depth > 200 m

UHE Models, Erice, 25 June 2006 (Seckel) Timing & vertex reconstruction 10 ns relative timing across array, for event reconstruction and pointing. Achievable with current IceCube DOM technology

UHE Models, Erice, 25 June 2006 (Seckel) AURA design (Ratlaff)

UHE Models, Erice, 25 June 2006 (Seckel) More on AURA

UHE Models, Erice, 25 June 2006 (Seckel) Acoustic at Pole (Boser) Status –Technique theoretically understood, but… –Attenuation ? –Background Noise ? South Pole Acoustic Test System (SPATS) –Instruments in three holes (2006/7)

UHE Models, Erice, 25 June 2006 (Seckel) Radio/Acoustic/Optical at SP (Besson etal)

UHE Models, Erice, 25 June 2006 (Seckel) SALSA: RF in salt domes Pro: –Salt domes are common –Cf ice:  =2.22, n=2.43 –Shielded by overburden Questions: –? attenuation –? drilling costs

UHE Models, Erice, 25 June 2006 (Seckel) Lunar observations: GLUE

UHE Models, Erice, 25 June 2006 (Seckel) NuMoon (Scholten et al) 100 MHz Vacuum Cosmic particle interaction θcθc Vacuum Cosmic particle interaction 3 GHz θcθc

UHE Models, Erice, 25 June 2006 (Seckel) NuMoon II

UHE Models, Erice, 25 June 2006 (Seckel) Model Independent Limits Goals –Reasonable, easy to apply, limits for theorists – must be fair to both experiments and models! –Fair comparison of experiments I. Collection of Models –Good: Always correct. –Bad: Hard to make graphical without misleading, not comprehensive, selection of models is subjective. May favor one exp. over another. II. Model Independent Bins –Good: Easy to describe, and compare. Model independent. –Bad: ad-hoc bin sizes. Not justified. Not really model independent. Common use tends to underestimate experimental reach. Convention not established Proposal: MI bins with underlying flux model ~1/EA –Good: Independent of physics model, characterized by experiment. Easy to compare experiments. Improves on scheme in common use. Graphical representation has reasonable meaning, and fairly represents experiments. –Bad: Community acceptance of yet another scheme?

UHE Models, Erice, 25 June 2006 (Seckel) Collection of model limits, e.g. RICE

UHE Models, Erice, 25 June 2006 (Seckel) This is just like the figure above. Not so Ad-Hoc anymore, but why does it work?

UHE Models, Erice, 25 June 2006 (Seckel) Power Law Models

UHE Models, Erice, 25 June 2006 (Seckel) Bin size:  limits  Curvature:   - 6 Limits

UHE Models, Erice, 25 June 2006 (Seckel) Summary UHE Models –p-acceleration, top down –GZK: robust, test of source models Radio detection –Large volume due to long attenuation –RF pulse calculations Radio & Acoustic Exps –RICE, ANITA, AURA, GLUE, NuMoon (others) –South Pole acoustic tests Model independent limits