icecube ehe analysis our findings and roadmap to analysis
DESCRIPTION
IceCube EHE analysis Our findings and roadmap to analysis. Shigeru Yoshida For the EHE working group. DOM response to high NPEs. ATWD or FADC?. “ EHE specific ” response!. Estimated number of photo-electrons per DOM. Log 10 (FADC based estimated NPE ). - PowerPoint PPT PresentationTRANSCRIPT
2006/6/212006/6/21 11
IceCube EHE analysisIceCube EHE analysisOur findings and roadmap to analysisOur findings and roadmap to analysis
Shigeru YoshidaShigeru YoshidaFor the EHE working groupFor the EHE working group
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DOM response to high NPEsDOM response to high NPEs
Log
10 (A
TW
D e
stim
ated
NP
E)
Estimated number of photo-electrons per DOM
ATWD or FADC?
Log
10 (F
AD
C b
ased
est
imat
ed N
PE
)
Log10 (ATWD based estimated NPE)
L
og10
(FA
DC
est
imat
ed N
PE
)
Log10 (MC Truth NPE) Log10 (MC Truth NPE)
Red: DOM of which ATWD charge is largerBlue: DOM FADC is larger
Npe saturation Npe saturation
“EHE specific” response!
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NPE Energy DistributionNPE Energy Distribution
E-1 fluxes
containedcontained
GZK Atmospheric GZK
107 1010 [GeV] 107 1010 [GeV] 107 1010 [GeV]
Log
Np
e
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NPE DistributionNPE Distribution
Distribution Distribution difference difference between the between the signals and signals and background! background!
GZKGZK
Atmospheric
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Zenith Angle DistributionZenith Angle Distribution
Signals peak at Signals peak at horizontal horizontal directiondirection
Background Background distribute over distribute over down-going down-going regionregion
GZKGZK
Atmospheric
up down
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Preliminary Event SelectionPreliminary Event Selection
GZK Atmospheric GZK
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Event Rate with completed Event Rate with completed detectordetector
GZK 0.35 events/year
GZK 0.31 events/year
Atmospheric 0.033 events/year
GZKGZK
Atmospheric
GZKGZK
Atmospheric
GZK: S. Yoshida et. al. (1997) ApJ 479:547 (m=4, Zmax=4)
IceCube Preliminary
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GZK Signal
Roadmap to analysisRoadmap to analysisAtmospheric BG
Standard CandleIn-Ice data9-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
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9-strings working data9-strings working data
Npe>104Npe>104
NDOM >80NDOM >80
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9-strings working data9-strings working data
Npe>104
~ 500Events/yr
Needs statistics ! to understandIntensity(Npe, zenith), DOM response in EHE regime
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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
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Why no problem in unblinding?Why no problem in unblinding?Signal stats in the following data is by far large.Almost independent confirmation!!
Expect
ed E
vent
Rate
[/y
ear]
This Year
Y2007
Y2008
x 2
x 1.5
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Why no problem in unblinding?Why no problem in unblinding?Background and Signals are so different inEnergies (Npe’s) and cos(1st-guess zenith)
This cut? This cut?Or this cut? Or this cut?
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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!!
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Beyond Npe and First-guessBeyond Npe and First-guessEnergy/Geometry recoEnergy/Geometry reco
e
NnNnP
Nn
k
i i
i
ii
i
!!!}){|}({
1
Waveform-based likelihood(proposed by Gary)
Utilize unscattered photon hits? (suggested by Lutz in 2004)
Including morenon-contained events
Log(Npe) Log(Energy)
cos(
1st g
uess
)
cos
(reco
)
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Our Bread and ButterOur Bread and Butter
Photo by David Boersma
Introducing “Yoshida” bottle(s)Your WG wins them if you publish your results earlier than anybody else!