RICE David Seckel, NeSS02, Washington DC, Sept ,/2002 R adio I ce C herenkov E xperiment PI presenter

RICE David Seckel, NeSS02, Washington DC, Sept ,/2002 NeSS: 10 min + 2 Concept Status Results ( astro-ph/ ) Future

RICE David Seckel, NeSS02, Washington DC, Sept ,/2002 Radio Detection of High Energy Neutrinos Goals PeV: AGN 1 km 3 EeV: GZK 10 3 km 3 Cherenkov radiation from  induced in-ice shower Signal ~ D Q ~ 0.25 E s /GeV l ~ R M ~ 10 cm Transparency > 1 km Thermal 250 k.8 km

RICE David Seckel, NeSS02, Washington DC, Sept ,/2002 EeV neutrino detection with RICE 5 km 1-10 PeV1-10 EeV _ Signal StrengthIce Properties CalibrationLPM effect e  e N  recoil hadrons  0 s interact

RICE David Seckel, NeSS02, Washington DC, Sept ,/ Rx (10 cm dipole) 5 Tx 3 Horns 4 Oscilliscopes (x4) DAQ PCs Pulse Generator Dry hole Pole: Network analyzer Antenna range Kansas: Deployment

RICE David Seckel, NeSS02, Washington DC, Sept ,/2002 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

RICE David Seckel, NeSS02, Washington DC, Sept ,/2002 Single Channel Calibrations MHz: +/- 3 dB (E) TX….RX antenna + amplifier calibrations cable (TX, RX) and filter relative geometry of TX/RX (r, q)

RICE David Seckel, NeSS02, Washington DC, Sept ,/2002 Monte Carlo Simulation Neutrino interaction e + /e - /  shower Radio pulse generation Propagation through ice Antenna & DAQ response

RICE David Seckel, NeSS02, Washington DC, Sept ,/2002 Interactions and Event types Interaction Model –isotropic  flux from upper hemisphere (2  sr) –charged and neutral currents –hadronic energy = y E, lepton energy = (1-y) E –Gandhi et al. ’98 cross-section d  /dy with ~20% reduction for Oxygen (EMC effect)

RICE David Seckel, NeSS02, Washington DC, Sept ,/2002 Shower Simulations Shower simulation –GEANT 3.21 (100 GeV – 1 TeV) 30% smaller than ZHS (but …GEANT 4 ??) –Extrapolate to higher energies –LPM from Alvarez & Zas –Hadronic cascades convert completely to EM with no LPM –EM & hadronic cascades treated separately Average 100 GeV shower

RICE David Seckel, NeSS02, Washington DC, Sept ,/2002 EM Pulse generation ALSO: Experimental results (Saltzberg, et al.) confirms coherence and Askaryan effect 1.Pulse increases with Energy 2.Narrows with frequency 3.Some small numerical differences between codes

RICE David Seckel, NeSS02, Washington DC, Sept ,/2002 Radio Attenuation in Ice Red – Westphal (Greenland) + Matsuoka (high freq) Black – Kawada(lab) + Matsuoka (high freq) (from Matsuoka)  ’ + i  ” Solid – Provorov (used by RICE) Dashed – Matsuoka + Westphal RICE bandpass

RICE David Seckel, NeSS02, Washington DC, Sept ,/2002 Pulse shape simulation Disc. threshold Background taken from data sample

RICE David Seckel, NeSS02, Washington DC, Sept ,/2002 Results of MC simulation Limited by attenuation 60,000 e - showers at E = 1 EeV Black dots – sample Red dots – events which would trigger RICE ~ 5% efficiency Limited by Cherenkov angle

RICE David Seckel, NeSS02, Washington DC, Sept ,/2002 RICE effective volume for e -,  showers Range due to varying signal strength by Range due to varying attenuation by Multiply by 2  sr This is appropriate for e charged current events.

RICE David Seckel, NeSS02, Washington DC, Sept ,/2002 LPM and hadronic showers With LPM Without LPM “Hadronic” E s = 20% E

RICE David Seckel, NeSS02, Washington DC, Sept ,/2002 Reconstruction of transmitter events  t =  50 ns for noise  t =  ns for  r = 10 m nearby  r = 0.1 R, < 1 km  ~ 10 deg  E/E ~ 0.5

RICE David Seckel, NeSS02, Washington DC, Sept ,/2002 Results of Data Analysis hrs livetime

RICE David Seckel, NeSS02, Washington DC, Sept ,/2002 Limits on diffuse e flux from e - showers a)Stecker & Salamon (AGN) b)Protheroe (AGN) c)Mannheim (AGN) d)Protheroe & Stanev (TD) e)Engel, Seckel & Stanev (GZK) Ranges are central 80%

RICE David Seckel, NeSS02, Washington DC, Sept ,/2002 Limits derived from e - showers ( e CC) hadronic showers (all CC+NC) a)Stecker & Salamon (AGN) d ) Protheroe & Stanev (TD) b)Protheroe (AGN) e) Engel, Seckel & Stanev (GZK) c)Mannheim (AGN) Ranges are central 80%

RICE David Seckel, NeSS02, Washington DC, Sept ,/2002 Near term future Beginning analysis of ~ 1 yr of data. Improve limits by ~ 10.

RICE David Seckel, NeSS02, Washington DC, Sept ,/2002 Longer term 100 GZK events/yr requires ~ 1000 km 3 (1 Eg) RICE: LPM no LPM Auger: tau e, mu LPM Needs Salt EUSO ANITA AMANDA/ANTARES IceCube/NEMO

RICE David Seckel, NeSS02, Washington DC, Sept ,/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) V eff (E > eV) > 20 km 3 sr [ e CC only] Limit improves by 2-18 with inclusion of hadronic channels, depending on spectrum. Limits may improve by 10 (again) with analysis of 1 yr data. 100 GZK  events per yr is conceivable

RICE David Seckel, NeSS02, Washington DC, Sept ,/2002 Intentionally left blank End of Talk

RICE David Seckel, NeSS02, Washington DC, Sept ,/2002 Thermal Background Red – Simulated detected showers (1 EeV) Black – Simulated noise – uncorrelated background Warnings: shower vertices are “true” positions not reconstructed. Should be OK inside 1 km. shower vertices are monoenergetic.

RICE David Seckel, NeSS02, Washington DC, Sept ,/2002 Systematic Effects (see astro- ph/ )