astroph0206371 David Seckel Ice CubeAMANDA collaboration mtg Stockholm

astro-ph/0206371 David Seckel, Ice. Cube/AMANDA collaboration mtg, Stockholm SE, 6/21 -25/2002

Outline • • • Concept * Deployment Status Event Rate Calculation – Interaction rate * – – • • • Simulation of signal generation * Propagation * Detector response Veff * Event Reconstruction Backgrounds & Filters * August 2000 data – Data summary * – Limits * • Discussion – Systematics * – LPM & hadronic showers * David Seckel, Ice. Cube/AMANDA collaboration mtg, Stockholm SE, 6/21 -25/2002

Radio Detection of High Energy Neutrinos * Goals Pe. V: AGN 1 km 3 Ee. V: GZK 103 km 3 Cherenkov radiation from n-induced in-ice shower S ~ DQ ~ 0. 25 Es/Ge. V l ~ RM ~ 10 cm Transparency > 1 km Thermal noise @ 250 k David Seckel, Ice. Cube/AMANDA collaboration mtg, Stockholm SE, 6/21 -25/2002

Pole: • 16 Rx (10 cm dipole) • 5 Tx • 3 Horns • 4 Oscilliscopes (x 4) • DAQ • PCs • Pulse Generator • Dry hole Deployment Kansas: • Network analyzer • Antenna range David Seckel, Ice. Cube/AMANDA collaboration mtg, Stockholm SE, 6/21 -25/2002

Interactions and shower simulations * • Interaction Model – ne isotropic from upper hemisphere (2 p) – charged current only – Gandhi et al. ’ 98 cross-section ds/dy with ~20% reduction for Oxygen (EMC effect) • Shower simulation – GEANT 3. 21 30% smaller than ZHS (but …GEANT 4 ? ? ) – LPM from Alvarez & Zas – no contribution from hadronic cascade David Seckel, Ice. Cube/AMANDA collaboration mtg, Stockholm SE, 6/21 -25/2002

Radio Attenuation in Ice * e = e’ + i e” Red – Westphal (Greenland) + Matsuoka (high freq) Black – Kawada(lab) + Matsuoka (high freq) (from Matsuoka) RICE bandpass Solid – Provorov (used by RICE) Dashed – Matsuoka + Westphal RICE bandpass David Seckel, Ice. Cube/AMANDA collaboration mtg, Stockholm SE, 6/21 -25/2002

Pulse shape simulation * A lot of work has gone into calibration of antennas, amps, cables, DAQ. See astroph/0112372 Background taken from data sample Disc. threshold David Seckel, Ice. Cube/AMANDA collaboration mtg, Stockholm SE, 6/21 -25/2002

Results of MC simulation * 60, 000 e- showers at E = 1 Ee. V Black dots – sample Red dots – location of events which trigger RICE Limited by Cherenkov angle David Seckel, Ice. Cube/AMANDA collaboration mtg, Stockholm SE, 6/21 -25/2002 ~ 5% efficiency Limited by attenuation

Multiply by 2 p sr RICE effective volume for e-, g showers * Range due to varying attenuation by 0. 5 -2 Range due to varying signal strength by 0. 5 -2 David Seckel, Ice. Cube/AMANDA collaboration mtg, Stockholm SE, 6/21 -25/2002

Reconstruction & Man made noise This is actually a transmitter event ! • dt = 50 ns for noise • dt = 25 ns for n • dr = 10 m nearby • dr = 0. 1 R , < 1 km • dq ~ 10 deg • d. E/E ~ 0. 5 David Seckel, Ice. Cube/AMANDA collaboration mtg, Stockholm SE, 6/21 -25/2002

Thermal Background * Red – Simulated detected showers (1 Ee. V) Black – Simulated noise – uncorrelated background Warnings: shower vertices are “true” positions not reconstructed. Should be OK inside 1 km. shower vertices are monoenergetic. David Seckel, Ice. Cube/AMANDA collaboration mtg, Stockholm SE, 6/21 -25/2002

Results of Data Analysis * 333. 3 hrs livetime David Seckel, Ice. Cube/AMANDA collaboration mtg, Stockholm SE, 6/21 -25/2002

Limits on diffuse ne flux from e- showers * a) b) c) d) e) Stecker & Salamon (AGN) Protheroe (AGN) Mannheim (AGN) Protheroe & Stanev (TD) Engel, Seckel & Stanev (GZK) AMANDA (Hundtermark) Ranges are central 80% David Seckel, Ice. Cube/AMANDA collaboration mtg, Stockholm SE, 6/21 -25/2002

Potential Systematic Effects * David Seckel, Ice. Cube/AMANDA collaboration mtg, Stockholm SE, 6/21 -25/2002

LPM and hadronic showers * “Hadronic” Es = 20% En Without LPM David Seckel, Ice. Cube/AMANDA collaboration mtg, Stockholm SE, 6/21 -25/2002 With LPM

Limits on power law fluxes PRELIMINARY Top set: ne CC only Bottom set: all n’s CC+NC AMANDA (Hundtermark) GZK challenge! David Seckel, Ice. Cube/AMANDA collaboration mtg, Stockholm SE, 6/21 -25/2002

Summary • Radio detection has a bright future • Demonstrated ability to reject surface backgrounds and work close to thermal limit • Major uncertainty is – attenuation in ice (high energy) – calibration (low energy) • Veff (E > 1018 e. V) > 20 km 3 sr [ne CC only] • Limits will improve by 4 -10 with inclusion of hadronic channels • Limits may improve by 10 (again) with analysis of 1 yr data. David Seckel, Ice. Cube/AMANDA collaboration mtg, Stockholm SE, 6/21 -25/2002