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RICE bounds on UHE Neutrino fluxes in the GZK Regime plus bounds on new physics. Data from 2000 through 2004 confront models of the world (PRELIMINARY). Outline. What RICE is What the new data say Calculation of bounds on GZK fluxes Results Calculation of bounds on LSG Results
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RICE bounds on UHE Neutrino fluxes in the GZK Regimeplus bounds on new physics Data from 2000 through 2004 confront models of the world (PRELIMINARY)
Outline • What RICE is • What the new data say • Calculation of bounds on GZK fluxes • Results • Calculation of bounds on LSG • Results • Summary and Conclusions
Radio Cherenkov Detection of Neutrinos 16 co-authors from Kansas, Delaware, Canterbury, MIT 16 Radio Receivers 200mX200mX200m Array Between 100m and 300m UNDER THE ICE at the SOUTH POLE A great debt owed to AMANDA
RICE data collected 2000 - 2004 by the Radio Ice Cherenkov Detector current RICE authors: Ilya Kravchenko,Dave Seckel, Jenni Adams, Steve Churchwell, Pauline Harris, Surujdeo Seunarine, Peter William, Alice Bean, Dave Besson *, Scott Graham, Sarah Holt, Shahid Hussain, Doug McKay, Josh Meyers, John Ralston, Rainer Schiel, Hanah Swift, *Contact: dzb@kuhep4.phsx.ku.edu
RICE Searches for UHE Cosmic Neutrino Hits in Antarctic Ice with Radio Antennas Coherent Cherenkov Pulses from Showers Pulses Amplified and Sent to Surface Trigger on 4 hits above Threshold* Triggered pulses Read into Oscilloscope, Saved Pulses are Time labeled - basis to reconstruct hits Acceptance of Above Summarized in Veff, the EFFECTIVE VOLUME *Background Fixes Discriminator Threshold
RICE Calibrations and Collateral Experiments • Direct in situ attenuation length and refractive index in-ice measurements made by RICERS • Antenna calibrations, gain calibrations, timing calibrations, vertexing tests, … are described in: • I. Kravchenko et al., Astropart. Phys. 19, (2003) 15; Flux bounds and a recap of the calibrations and testing are presented in I Kravchenko et al., Astropart. Phys. 20, (2003) 195
Effective Volume Comments • Landau, Pomeranchuk, Migdal effect (LPM) makes a difference only to EM showers • Radio ray bending costs us effective volume. This feature is included here for the first time. • Separate livetimes must be logged for each threshold setting, reflecting varying background conditions.
Transmitter Location Reconstruction True (known) Transmitter Depth
Next RICE LIMITS ON COSMOGENIC FLUXES
Cosmogenic Fluxes, Comments: We choose a wide range of normalizations and several different forms of energy dependence to illustrate the corresponding range of rate expectations. Each of the cases shown is one out of a span of models (input parameter choices), that each group presents. The large is the largest one in the KKSS study, the medium is the smallest in the PJ study, and the small is the smallest in the ESS study. There is overlap among all of the groups.
After ~ 1.5 years livetime, what does RICE see? NO NEUTRINO EVENTS PASS FINAL CUTS - VERTEX LOCATION AND CONE FIT.
Rate Calculations and 95% CL Limits on Cosmogenic Neutrino Fluxes • All neutrino flavors are included • EM (electron neutrino only) and hadronic showers included, so CC and NC counted • Improved Monte Carlos of Veff and offline cut efficiencies reduce nominal acceptance compared to 2000 and 2003 reports • 2 years more data and lower ‘03 and -’04 backgrounds compensate • {(Flux)bound = 3x(TxRate)-1modelx(Flux)model }* * @ 95%CL, where T is the livetime.
Next: more limit calculations LOW SCALE GRAVITY: (LSG) limits on scale
Low Scale Gravity Cross Sections • Need X- sections for BH production : with and without inelasticity (impact parameter effect) • Need X-cross sections for KK -graviton exchange in eikonal (UNITARY) approximation • Need shower rates from BH and KK-graviton (eikonal) AND from SM interactions for total rate • All cross sections rise with energy, as does Veff, while the fluxes fall. • Rates rely on X-section x Volume x Flux, and the product reveals the most sensitive energy range for a given detector.
RICE 2000-2004---- ~ 1.5 years live-time Event Rates From Cosmogenic Neutrinos LSG, 1 TeV Scale Standard Model LSG, 2 TeV Scale
RICE 2000-2004 ---- bounds on LSG from cosmogenic neutrinos
Summary • RICE has completed a first analysis of all data from 2000 thru 2004 • No neutrino candidates survive all cuts • Preliminary bounds on representative - “small, medium and large” - GZK, or COSMOGENIC , flux models • Bounds on Planck mass in 6-d low scale gravity models via elastic and BH production. Degeneracies confuse the interpretation of data.
RICE continuesto determine the STRONGEST LIMITSfor the energy rangeabove about 1018 eV
Conclusions • the LARGEST cosmogenic flux model on the verge of 2-sigma EXCLUSION • the INTERMEDIATE and SMALL FLUX models still 101-101.5 below confrontation • Depending on flux model and on low scale gravity model dependence, lower bounds on the Planck mass range from 1 to 10 TeV. • Many Interpretations are possible. IT’S STILL EARLY IN THE GAME1
RICE 2000-2004 ---- SM bound on cosmosgenic neutrino flux New Limit RICE PRELIMINARY
CROSS SECTIONS 1. Black holes without inelasticity D. W. MCKAY UNIVERSITY OF KANSAS
Cross sections continued…. 2. Black holes with inelasticity Where, D. W. MCKAY UNIVERSITY OF KANSAS
Cross sections continued…. Graviton exchange D. W. MCKAY UNIVERSITY OF KANSAS
Cross sections continued…. Graviton exchange continued… D. W. MCKAY UNIVERSITY OF KANSAS
Shower rates continued…. Showers from BHD D. W. MCKAY UNIVERSITY OF KANSAS
Shower rates continued…. Showers from graviton exchange D. W. MCKAY UNIVERSITY OF KANSAS