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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. 17 underice Rx dipoles + 3 surface horn Rx + 5 Tx dipoles 200x200x200 m cube above AMANDA - PowerPoint PPT Presentation
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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).