Mar 9, 2005 GZK Neutrinos Theory and Observation D. Seckel, Univ. of Delaware

GZK neutrnos, theory and observation, Kansas Mar 10, 2005 Topics “Theory” –UHECR - overview –GZK neutrinos (Engel, Seckel, Stanev) –Model choices and parameters –GZK neutrinos and UHECR spectrum (with TS) Detection issues –Radio detection Rates –Scaling of Askaryan pulses –HE interactions Event Topology (old picture) New considerations (Scales, LPM, dE/dX) –Scaling dE/dX –Photonuclear –Pair Production –LPM issues –Line radiation Expectaions for e,  at PeV, EeV, ZeV

GZK neutrnos, theory and observation, Kansas Mar 10, 2005 Start with cosmic rays Composition Spectrum Source Propagation History

GZK neutrnos, theory and observation, Kansas Mar 10, 2005 UHECR AGASA - HiRes - + Propagation

GZK neutrnos, theory and observation, Kansas Mar 10, 2005 Propagation UHECR with E > are young (<0.01 t 0 ) + Magnetic fields: Could be diffusive, Old and Local?

GZK neutrnos, theory and observation, Kansas Mar 10, 2005 UHECR puzzles Sources young, but no candidates. (AGASA: clustering?) Solutions –Bad data (my personal favorite) –Stable penetrating particle –Diffuse source (particle decay?) –Local source + magnetic fields More Data –Build Pierre Auger Obs. –But degeneracy of models a)Flat spectrum, evolution, galactic contribution b)Steep spectrum, no evolution, no galaxy

GZK neutrnos, theory and observation, Kansas Mar 10, 2005 GZK Neutrino production I

GZK neutrnos, theory and observation, Kansas Mar 10, 2005 GZK neutrino production II

GZK neutrnos, theory and observation, Kansas Mar 10, 2005 Simple scaling of GZK Spectrum: (E p ) -(1+  ) Evolution (1+z) m Matter dominated cosmology (1+z) -5/2 Spacing  q = 1 dB

GZK neutrnos, theory and observation, Kansas Mar 10, 2005 Neutrinos break degeneracy a) Flat spectrum, evolution, galactic contribution b) Steep spectrum, no evolution, no galaxy c) Cutoffs, Lambda…

GZK neutrnos, theory and observation, Kansas Mar 10, 2005 Neutrino Detection Atmospheric GeV Astro-Sources 0.1 TeV - 10 PeV GZK EeV 50 m 500 km 1 km 5 km

GZK neutrnos, theory and observation, Kansas Mar 10, p cross-section 5% in 3 km salt

GZK neutrnos, theory and observation, Kansas Mar 10, 2005 Shower Rate per km 3

GZK neutrnos, theory and observation, Kansas Mar 10, 2005 Radio Detection of Showers Askaryan: Coherent radiation S ~  Q ~ 0.25 E s /GeV ~ R M ~ 10 cm  /l ~ 3 deg Confirmed by –SLAC T444, Saltzberg et al. PRL 2001 –SLAC T460, Gorham et al. 2002

GZK neutrnos, theory and observation, Kansas Mar 10, 2005 Scaling behavior fractional excess Single particle & shower signals Includes LPM effect z y cc to observer

GZK neutrnos, theory and observation, Kansas Mar 10, 2005 RF spectrum 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

GZK neutrnos, theory and observation, Kansas Mar 10, 2005 Phases I ZHS phase? gaussian profile symmetric – no phase in g(z) Realistic shower profiles should have phases Proposal: use phases based on RSBMRS

GZK neutrnos, theory and observation, Kansas Mar 10, 2005 Phases II

GZK neutrnos, theory and observation, Kansas Mar 10, 2005 Radio Event Topology: Old Picture

GZK neutrnos, theory and observation, Kansas Mar 10, 2005 New Considerations (dE/dX)

GZK neutrnos, theory and observation, Kansas Mar 10, 2005 Scaling of dE/dX

GZK neutrnos, theory and observation, Kansas Mar 10, 2005 Photonuclear review I Comments From DRSS = 3km salt  –y-distribution important

GZK neutrnos, theory and observation, Kansas Mar 10, 2005 Photonuclear review II  ~  /(  +m lep ) ~  /(  +m lep ) Growth with  due to growth in photon cross- section (QCD) with E

GZK neutrnos, theory and observation, Kansas Mar 10, 2005 Pair Production From LKV  ~ 1/m lep ~ m e /m lep ? Quasi-continuous

GZK neutrnos, theory and observation, Kansas Mar 10, 2005 LPM issues Is reduction in  eN-eN    N-Nee the whole story ?   N (see S. Klein) –Convert energy to hadronic shower  eN-eNX,(10 19 eV?),  eN-eNee (10 20 eV (lpm?))

GZK neutrnos, theory and observation, Kansas Mar 10, 2005 Line radiation (just like SLAC salt stack !?) Showers vs radiation from a moving “charge” Coherence region along track Lumpy? L d

GZK neutrnos, theory and observation, Kansas Mar 10, 2005 Expectations e  