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Searching for ultra-high energetic neutrinos Why - How - Where - When. Rolf Nahnhauer DESY. WHY?. Observation:. Interpretation, Model, Theory:. Improvements: ( in ~1500 years) - Epicycle on epicycle on… - Eccentric theory - Aequants - …. Message: d ecide carefully
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Searching for ultra-high energetic neutrinos Why - How - Where - When Rolf Nahnhauer DESY DESY, ZeuthenKlausur
WHY? DESY, Zeuthen Klausur
Observation: Interpretation, Model, Theory: Improvements: (in ~1500 years) - Epicycle on epicycle on… - Eccentric theory - Aequants - … Message: decide carefully - What do we really know? (from model independent measurements) - What do we assume? - What do we speculate? BUT: Basic assumption wrong solution DESY, Zeuthen Klausur
Our present model: Our present observations: Photons Neutrinos Protons Our present instruments: Our present status (a few examples ): DESY, Zeuthen Klausur
Ultra-high energy neutrinos Possible sources: - AGN’s (not discussed here) - neutrinos from GZK-effect - topological defects New insights from the study of neutrinos above ~1017eV about: - Astrophysics (not discussed here) - Particle Physics (2 examples) - Cosmology (2 examples) - Basic symmetries (1 example) DESY, Zeuthen Klausur
Pre-requisite: Limits from particle propagation through the universe 100 EeV Protons travel ~30 Mpc 10 TeV photons travel ~100 Mpc Neutrinos:- travel un-effected by dust and B-fields- interact only weakly- can escape from thick dense sources At high energies only neutrinos can give information about most of the universe DESY, Zeuthen Klausur
Cosmic rays interact with CMB photons and produce through Δ+ resonance If UHE-CR exist they should undergo GZK mechanism If GZK happens a neutrino flux is guaranteed GZK neutrinos BZ neutrinos GZK mechanism: a guaranteed source of neutrinos - Missing statistics? - No more sources?- No more power? - or real GZK? detect neutrinos V. S. Berezinsky, G.T. Zatsepin, PhysLett B 28 (1969)423 DESY, Zeuthen Klausur
BZ neutrinos from cosmological distances point back to theUHECR sources (within a GZK length precision) BZ neutrinos: astronomy for UHE proton sources throughout the universe < 3 degrees for a source at 1 Gpc “GZK sphere” DESY, Zeuthen Klausur
BZ neutrino flux: prediction and detection The standard case: An extreme case: L.A. Anchordoqui, Phys.Rev. D76(2007)123008 3.00 0.30 0.03 3.00 0.30 0.03 from P. Gorham, March 2010 Madison D. Seckel and T. Stanev, 2008 DESY, Zeuthen Klausur
Particle Physics with UHE neutrinos I:cross section measurements R.Gandhiet al. Phys.Rev. D58 (1998)093009 from PDG BZ- range Extrapolated over nine orders of magnitude xx Measure reasonable number (O(100)) of BZ-neutrinos at differentzenith angles get access to in the 1017 – 1020eV range sqrt (sN) = sqrt (2m E) = 14 TeV(E/1017eV)1/2 DESY, Zeuthen Klausur
Several effects at energies > 1017eV may change the cross section by orders of magnitude from A.Ringwald, ARENA 2005 short dashed: sphalerons [43,44] long dashed: p-branes [45] dotted: string excitations [46] DESY, Zeuthen Klausur
Cosmology and UHE neutrinosrelic neutrino detection For early ideas see e.g.: T. Weiler, Phys.Rev. Lett. 49(1982)234 S. Yoshida, G. Sigl, S. Lee,Phys Rev. Lett. 81(1998)5505 resonant annihilation of UHE neutrinos with relic neutrino background particles UHE neutrinos from topological defects CMB: T = 2.752 K from A. Ringwald, Arena 2005 dip in neutrino flux spectrum DESY, Zeuthen Klausur
Particle Physics with UHE neutrinos II:neutrino mass spectroscopy Use information the other way around: absorption lines in neutrino spectrum point to neutrino mass(es) But time evolution of universe: Moving target ’s energy smearing Compromises individual mass determination First peak could determine mass hierarchy ideal experiment C. Barenboim,O. Mena Requero, C. Quigg, Phys. Rev. D71 (2005)083002 DESY, Zeuthen Klausur
Basic symmetries and UHE neutrinosPlanck scale Lorentz invariance violation offers possibility for neutrino splitting: Log (L/Mpc) D. M. Mattingly et al., JCAP1002:007,2010(DESY 09-168) leads to cut-off of spectrum corresponding to -scale parameter and enhancement at lower energies DESY, Zeuthen Klausur
HOW? DESY, Zeuthen Klausur
UHE neutrino detection techniques Detected radiation: - Optical Cherenkov or fluorescence - Radio Cherenkov (coherent) - Acoustic waves Target media: - Air: atmosphere - Water: oceans, lakes - Salt: salt domes - Ice: (ant)-arctic glaciers - Rock: lunar regolith - Permafrost: Siberian river valleys DESY, Zeuthen Klausur
air dense medium acoustic“pancake” v-induced cascade coherentradio signal opticalCherenkov signal Best solution: Hybrid neutrino detection Energy range for typical detector 1016 eV 1017 eV 1018 eV • Multiple detection of same signal possible in several materials (best in ice) • Extend energy range of sensitivity and enlarge volume (bigger spacing?) • Calibrate R with O and cross-calibrate A & R • Improve energy and direction reconstruction • More efficient background rejection Trust your signal ! DESY, Zeuthen Klausur
The next radio detector at the Pole - ARA 37 clusters nearly without correlations per eventNo hybrid (acoustic) optionforeseen and possible holes too distant (1.3-2 km) holes not deep enough 148 holes DESY, Zeuthen Klausur
100km2 20 km 400 km2 20 km Adequate radio detector concept 2009 SATRA - Sensor Array for Transient Radio Astrophysics K.Hanson, P Sandstroem et al., 1km2 200Vp-p Stimulus 30km2 TDA Output AURA Front End Output - readout only waveform “envelop” - rely strongly on correlated antenna hits per event 500m x 500m sensor spacing shown DESY, Zeuthen Klausur
Radio vs. acoustic triggers 10 mPa 1 mPa 35% 16% 29% 11% 18% 6% DESY, Zeuthen Klausur
WHERE? DESY, Zeuthen Klausur
Optimal target material today: Ice - Antarctica Amundsen - Scott station, US dominated by US (NSF) PI has to be from US institution dominated by Europe PI has to come from France or Italy Concordia station,France, Italy long term Astrophysics program exists DESY, Zeuthen Klausur
WHEN? DESY, Zeuthen Klausur
What has to be done first: Check the general possibilities of a hybrid detector concept for a x*100 km3cosmogenic neutrino detector by doing detailed simulations Set up the basic requirements for a necessary R&D program, as there are e.g. - new (robotic) drilling and deployment technologies - new power and communication systems - new type of cable integrated sensors (optical, radio, acoustic,….) - new data collection, reduction and transfer concepts - etc., etc. A 2-3 orders of magnitude larger detector than ever built can not just be a blow-up of an older one, but needs new ideas and techniques It is NOT realistic to work out a concept which tomorrow can be startedto be built – the realistic timescale is at least of O(10years) DESY, Zeuthen Klausur
Start now: - propagate the basic ideas and possible concepts - look for interested partners in science and technology - set up an organized long term program with well defined work packages and responsibilities - begin a complex R&D program - reconsider necessities and possibilities about every three years DESY would be an ideal place to launch such a program DESY, Zeuthen Klausur
We have been pioneers before We can do it again Thanks to J.P. Yanez for the idea DESY, ZeuthenKlausur