RICE bounds on UHE Neutrino fluxes in the GZK Regime

plus bounds on new physics

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)

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

16 co-authors fromKansas, Delaware,Canterbury, MIT

16 Radio Receivers 200mX200mX200mArray Between 100m and 300m UNDER THE ICE at the SOUTH POLE

A great debt owed toAMANDA

Radio Cherenkov Detection of NeutrinosRadio Cherenkov Detection of Neutrinos

RICE data collected 2000 - 2004by 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.

MC hit distribution with raytracing

Transmitter Location Reconstruction

True (known)

Transmitter Depth

RICE 2000-2004 ------ live-time Vs. discriminator threshold

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.

RICE 2000-2004 ---- SM bound on cosmogenic neutrino flux

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.

CROSS SECTIONS PLOTS

Standard Model

LSG, 1 TeV Scale

LSG, 2 TeV Scale

RICE 2000-2004---- ~ 1.5 years live-time Event Rates From Cosmogenic Neutrinos

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 ---- volume with LPM effect

RICE 2000-2004 ---- volume without LPM effect

RICE---- Volume versus Threshold

RICE 2000-2004 ---- SM bound on cosmosgenic neutrino flux

RICE PRELIMINARY

New Limit

1. Black holes without inelasticity

CROSS SECTIONS

UNIVERSITY OF KANSASUNIVERSITY OF KANSASD. W. MCKAYD. W. MCKAY

2. Black holes with inelasticity

Cross sections continued….

D. W. MCKAYD. W. MCKAY UNIVERSITY OF KANSASUNIVERSITY OF KANSAS

Where,

Graviton exchange

Cross sections continued….

D. W. MCKAYD. W. MCKAY UNIVERSITY OF KANSASUNIVERSITY OF KANSAS

n

c

b

bbs ⎟

⎠

⎞⎜⎝

⎛=),(χ

Graviton exchange continued…

Cross sections continued….

D. W. MCKAYD. W. MCKAY UNIVERSITY OF KANSASUNIVERSITY OF KANSAS

Showers from BHD

Shower rates continued….

D. W. MCKAYD. W. MCKAY UNIVERSITY OF KANSASUNIVERSITY OF KANSAS

Shower rates continued….

D. W. MCKAYD. W. MCKAY UNIVERSITY OF KANSASUNIVERSITY OF KANSAS

Showers from graviton exchange