04/18/2304/18/23 11

IceCube EHE analysisIceCube EHE analysisPresent Status and Future PlanPresent Status and Future Plan

Shigeru YoshidaShigeru YoshidaFor the EHE working groupFor the EHE working group

04/18/2304/18/23 1111

Preliminary Event SelectionPreliminary Event Selection

GZK Atmospheric GZKV01-07-04 (DC1)

04/18/2304/18/23 1212

Npe - Energy Npe - Energy V01-07-04 (DC1)

04/18/2304/18/23 1515

Npe - Energy Npe - Energy V01-09-03 MCHits / DOM < 100000

FADC bins 50 ~ 1 usec

04/18/2304/18/23 1818

9-strings working data9-strings working data

Npe>104Npe>104

NDOM >80NDOM >80

Npe>105 Npe>105

04/18/2304/18/23 1919

9-strings working data9-strings working data

Npe>104

~ 500Events/yr

Needs statistics ! to understandIntensity(Npe, zenith), DOM response in EHE regime

04/18/2304/18/23 2020

GZK Signal

Roadmap to analysisRoadmap to analysisAtmospheric BG

Standard Candle

In-Ice data

9-strings unblinded data

Energy

Npe

Log(

Npe

)

NDOM

Cos(

zeni

th)

Log(Npe)

Cos(

zeni

th)

Log(Npe)

IceSim IceSim

))cos(,(

Ef

dE

dN

Tune

Energy

Eff.

Area

Extrapolate to signal domain

Empirical Model

Tune

04/18/2304/18/23 2121

Available level1 EHE DataAvailable level1 EHE Data

N events in a file

Samples used in slides 1/22 of Availablesample

Nch>50sample

04/18/2304/18/23 2222

Waveforms… Waveforms… ProblemsProblems

1. Samples at random

2. Corrected by 150 ns offset

3. Corrected random amplitude samples

04/18/2304/18/23 2323

FADC 50-6=44 bins (=1.1 microsecond) …. Too short!!Very difficult baseline estimation

For FADC zero baseline is used in the followingATWD is of course far too short.

For ATWD the ‘iteration method’ but not perfect, still

04/18/2304/18/23 2424

MC – IC9 data comparisonMC – IC9 data comparisonV01-07-04 (DC1) IC-9 data

~E-4 ~E-4

04/18/2304/18/23 2525

MC – IC9 data comparisonMC – IC9 data comparisonV01-09-01 (DC2) IC-9 data

(Only 5% of total data sample)

04/18/2304/18/23 2626

MC – IC9 data comparisonMC – IC9 data comparisonV01-09-01 (DC2) IC-9 data

(Only 5% of total data sample)

04/18/2304/18/23 2727

Muon bundlesMuon bundles1PeV bundle of 1000 muons (1TeV/muon)• Npe only would not be able to resolve tracks

• We do not know cosmic ray intensity in EHE

• We do not know cosmic ray composition in EHE

• Corsika has not reconstructed AGASA/Auger data9-strings “EHE” REAL DATA

Log(Npe)

Cos(

zeni

th)

Build Empirical Model

IceSim

))cos(,(

ENf

dE

dNm

04/18/2304/18/23 2828

GZK Signal

Roadmap to analysisRoadmap to analysisAtmospheric BG

Standard Candle

In-Ice data

9-strings unblinded data

Energy

Npe

Log(

Npe

)

NDOM

Cos(

zeni

th)

Log(Npe)

Cos(

zeni

th)

Log(Npe)

IceSim IceSim

))cos(,(

Ef

dE

dN

Tune

Energy

Eff.

Area

Extrapolate to signal domain

Empirical Model

Tune

December2006

On-going

November2006

May 2007

04/18/2304/18/23 2929

The EHE track reco : PDF

1017 eV50 m

100 m

200 m

300 m

1 p.e.1 p.e.

04/18/2304/18/23 3030

The EHE track reco

100 PeV100 PeV

Parameterized functionMC data

Profile (MC data)

Waveform Comparison Energy Reconstruction!

04/18/2304/18/23 3131

Sensitivity/Bound Sensitivity/Bound Quasi-differential Quasi-differential methodmethod

S. Yoshida et. al. (2004)Phys. Rev. D 69 103004

Bound: energy dependent!!

][/3.2)( )( nobservatioevent TEdLogE

dJN

This is MODEL independent!!

04/18/2304/18/23 3232

The Goal in 2007The Goal in 2007

Publish the 1Publish the 1stst results of EHE results of EHE search search

http://www.ppl.phys.chiba-u.jp/research/IceCube/EHE/