RICE Status Report

RICE Status Report

1) Technique & calibration

2) UHE neutrino limits (soon-to-be-released-once-the-mud-wrestling-is-over)

3) Low-scale gravity UL’s

4) RICE-II: Duty now for the future

RICE at a glance• 17 underice Rx dipoles + 3 surface horn Rx

+ 5 Tx dipoles – 200x200x200 m cube above AMANDA– 200500 MHz bandpass– Digital scope DAQ– 8.192 us waveform capture/event– “Forced”=“Unbiased” triggers to capture

background conditions– Data-taking since 1999

Transmitter Location Reconstruction

True (known) Transmitter Depth

Single Channel Absolute Gain Calib.

200-500 MHz: <3 dB (E),Likely better for pulses

NWAcableTxRxampcableNWA • antenna + amplifier calibrations• cable (TX, RX) and filter• relative geometry of TX/RX

Glaciology-n(z) by TxRx t=c/n

Data – surface reflections (03 data)

Bottom echo measures attenBottom echo visible thru 5.6 km! (20 dB noise reduction [averaging])

Bedrock/2850m

Absorption (Im(eps)) at SP

Ray Tracing

WAVEFORMS:Tx → Rx

simulation vs. data:

Data bandwidth slightly better

than MC prediction

data

simulated

MC MC SimulationsSimulations

MC simulations: Angular Resolution

+Energy resolution~50% for r<1 km

Monte Carlo efficiency

• Generate expected waveforms from Nshower

• Embed waveforms in “forced” trigger data– Sample over course of data-taking

• Smear MC by timing uncertainty (~10 ns)– Double-counting?

• Reconstruct with cuts as if data

• Efficiency~50%

Compare vx/vy/vz for 4-hit data vs 4-random time

Data more peaked @ cntr

Irreducible (thermal) bkgnds – ~50% of triggers when “RF-quiet”

Remaining bkgnds: dominantly surface transients

Data Summary – 1999April 2005

Total of ~1.5 yrs. Livetime for current analysis

Old vs. New (corrected ray-tracing + other refinements) effective volume

Aside: “The energy has to go somewhere”. Compensating effect of caustics, or after-pulses NOT included in Veff calc.

RICE (2000-2004) BOUNDS ON FLUXES

(Q=-|q|)=momentum transfer22 22

22 2

2( , ) ( , )(1 )F W

W

G ME Mdxq x Q xq x Q y

dxdy Q M

1. PDFs have not been measured in the required (x,Q) range. (10-3>x>10-9) – extrapolate (CTEQ5) into low x-regime2. Look for anomalous enhancements in neutrino-nucleon cross-section.

Example: Charged current Weak interaction (nu-nucleon)

neutrino

nucleon

Assume there are large compact extra dimensions. Only graviton sees these dimensions:gravity may become strong around electroweak scale (E(c.m.)~ O(1TeV)). Above the mass scale M_D, expect graviton exchange and micro black hole formation; expect enhancement of the neutrino-nucleon cross-sections. FREE PARAMETERS: number of extra dimensions (n); mass scale (M_D); minimum mass (M_BH0) required for black hole formation.=> for UHE neutrinos….

An example: LSG VS SM

LSG MAY BECOME DOMINANT ABOVE A FEW PeV

BOUNDS ON LOW SCALE GRAVITY

WEAKEST

STRONGEST

Paper release being held up internally pending completion of evaluation of systematic errors:

1) Uncertainty in attenuation length (most corrections drive Latten up)

2) Uncertainty in ray tracing (enhancement due to focusing being studied, although not to be included in results)

3) Smaller:1) Pattern recognition/vertexing within limits

of amplitude and timing uncertainties2) Transfer function uncertainties

Other things that we didn’t find

GRB coincidences (BATSE catalog+), Air Shower coincidences using SPASE coincidence trigger, SGR1806 (27 Dec 2004) flare, muon bremstrahlung (your model here)…

Next: monopole search: M=1 PeV monopole, ~104 loses ~20 PeV/km via photonuclear and pair production

RxDAQ hardware scheme

RICE-II / Hardware ready for deployment Nov., 2005…

Transient Response

Input signal size into OF linkS:kT noise = 3:1 = local trigger requirement

UHE nu+BH results “in the mail”

• Current Hardware will operate thru 2007 (MAPO elevation)

• RICERICE-II transition:– “When you see a fork in the road, take it”.

• To get to “next level”, need hardware improvements + bigger footprint (see Justin talk tomorrow on projected neutrino sensitivity improvement).